Transportation Soil Engineering in Cold Regions, Volume 1: Proceedings of TRANSOILCOLD 2019 (Lecture Notes in Civil Engineering, 49) 9811504490, 9789811504495

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Lecture Notes in Civil Engineering

Andrei Petriaev Anastasia Konon   Editors

Transportation Soil Engineering in Cold Regions, Volume 1 Proceedings of TRANSOILCOLD 2019

Lecture Notes in Civil Engineering Volume 49

Series Editors Marco di Prisco, Politecnico di Milano, Milano, Italy Sheng-Hong Chen, School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan, China Ioannis Vayas, Institute of Steel Structures, National Technical University of Athens, Athens, Greece Sanjay Kumar Shukla, School of Engineering, Edith Cowan University, Joondalup, WA, Australia Anuj Sharma, Iowa State University, Ames, IA, USA Nagesh Kumar, Department of Civil Engineering, Indian Institute of Science Bangalore, Bangalore, Karnataka, India Chien Ming Wang, School of Civil Engineering, The University of Queensland, Brisbane, QLD, Australia

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Andrei Petriaev Anastasia Konon •

Editors

Transportation Soil Engineering in Cold Regions, Volume 1 Proceedings of TRANSOILCOLD 2019

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Editors Andrei Petriaev Emperor Alexander I St. Petersburg State Transport University St. Petersburg, Russia

Anastasia Konon Emperor Alexander I St. Petersburg State Transport University St. Petersburg, Russia

ISSN 2366-2557 ISSN 2366-2565 (electronic) Lecture Notes in Civil Engineering ISBN 978-981-15-0449-5 ISBN 978-981-15-0450-1 (eBook) https://doi.org/10.1007/978-981-15-0450-1 © Springer Nature Singapore Pte Ltd. 2020 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Organizing Committee

Honorary Chair Dr. Alexander Y. Panychev, Rector of Emperor Alexander I St. Petersburg State Transport University, Russia

Conference Chair Dr. Andrei Petriaev, “Construction of roads” Department, Emperor Alexander I St. Petersburg State Transport University, Russia

Vice-chairs Prof. Jiankun Liu, School of Civil Engineering, Sun Yat-sen University, China Prof. Erol Tutumluer, Chair of TC202, ISSMGE, University of Illinois, Urbana-Champaign, USA

Conference Secretary Dr. Anastasia Konon, “Construction of roads” Department, Emperor Alexander I St. Petersburg State Transport University, Russia

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Organizing Committee

Conference Committee Members Local Committee Vice-chairs Prof. Tamila S. Titova, Vice-rector, Emperor Alexander I St. Petersburg State Transport University, Russia Prof. Nikolai S. Bushuev, Dean of Transport Construction Faculty, Emperor Alexander I St. Petersburg State Transport University, Russia Prof. Vladimir V. Egorov, Dean of Civil Construction Faculty, Emperor Alexander I St. Petersburg State Transport University, Russia Dr. Alexey F. Kolos, Head of “Construction of roads” Department, Emperor Alexander I St. Petersburg State Transport University, Russia Prof. Larisa B. Svatovskaya, Head of “Engineering Chemistry” Department, Emperor Alexander I St. Petersburg State Transport University, Russia Prof. Alexander P. Lediaev, Head of “Tunnels and Underground Railways” Department, Emperor Alexander I St. Petersburg State Transport University, Russia Viktor V. Gachits, “Construction of roads” Department, Emperor Alexander I St. Petersburg State Transport University, Russia Dr. Antonina S. Sakharova, “Engineering Chemistry” Department, Emperor Alexander I St. Petersburg State Transport University, Russia Svetlana A. Petrenko, “Construction of roads” Department, Emperor Alexander I St. Petersburg State Transport University, Russia

International Committee Prof. Charles Ng, President of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE), The Hong Kong University of Science and Technology, Kowloon Prof. Chungsik Yoo, President of International Geosynthetics Society (IGS), College of Engineering, Sungkyunkwan University, Seoul Prof. Martin Ziegler, Geotechnical Engineering and Institute of Foundation Engineering, Soil Mechanics, Rock Mechanics and Waterways Construction, RWTH Aachen University, Aachen Prof. Antonio Gomes Correia, Immediate past Chair of the TC202, ISSMGE, University of Minho, Braga Prof. Abdelmalek (Malek) Bouazza, Chair of TC215 Environmental Geotechnics, ISSMGE, Monash University, Australia Prof. Takashi Ono, Chair of TC216 Frost Geotechnics, ISSMGE Prof. Jorge G. Zornberg, University of Texas at Austin

Organizing Committee

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Dr. Jacek Kawalec, Silesian University of Technology, Poland Prof. Askar Zhussupbekov, Eurasian National University, Astana Prof. Eun Chul Shin, College of Urban Science, Incheon National University, Incheon Prof. Devendra Narain Singh, Indian Institute of Technology Bombay, Mumbai Prof. Satoshi Akagawa, Cryosphere Engineering Laboratory, Hachioji, Tokyo Prof. Jong-Sub Lee, School of Civil, Environmental and Architectural Engineering, Korea University, Seoul Prof. Valentin V. Vinogradov, Russian University of Transport, Moscow Prof. Taisiya V. Shepitko, Russian University of Transport, Moscow Prof. Alexander L. Isakov, Siberian Transport University, Novosibirsk Prof. Evgeniy S. Ashpiz, Russian University of Transport, Moscow Dr. Daniele Cazzuffi, President of the Italian Chapter of IGS—CESI SpA, Milano Prof. Gökhan Baykal, Department of Civil Engineering, Faculty of Engineering, Bogazici University, Istanbul Prof. Armen Z. Ter-Martirosyan, Moscow State University of Civil Engineering (National Research University), Moscow Prof. Svyatoslav Ya. Lutskiy, Russian University of Transport, Moscow Simon Dumais, President of Permafrost Young Researchers Network (PYRN), University Laval, Quebec Prof. Tatsuya Ishikawa, Hokkaido University, Sapporo Prof. Ivan Vanicek, ISSMGE Vice-president for Europe 2009–2013, Czech Technical University, Prague Prof. Andreas Loizos, Laboratory of Pavement Engineering, National Technical University of Athens Prof. Jean Cote, University Laval, Quebec Prof. Pauli Kolisoja, Tampere University of Technology Prof. Sergey A. Kudryavtsev, Nominated Member of TC216 Frost Geotechnics, ISSMGE, Far Eastern State Transport University, Khabarovsk Prof. Vladimir N. Paramonov, Emperor Alexander I St. Petersburg State Transport University, Russia Prof. José Neves, University of Lisbon Prof. Zhaohui Yang, University of Alaska Anchorage Prof. Katarzyna Zabielska-Adamska, Bialystok University of Technology Prof. Inge Hoff, Department of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), Trondheim Prof. Luljeta Bozo, Polis University, Tirana Dr. Andrey A. Zaitsev, Moscow State University of Railway Engineering, Moscow Dr. Elena Scibilia, Department of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), Trondheim Dr. Nikolai K. Vasiliev, Department of Soil Mechanics and Geotechnics, JSC “Vedeneev VNIIG”, St. Petersburg Prof. Xinglong Wang, Heilongjiang Institute of Highways and Transport Research Prof. Xiong Zhang, Missouri University of Science and Technology

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Organizing Committee

Prof. Dongqing Li, State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu Prof. Igor Sakharov, Saint-Petersburg State University of Architecture and Engineering Prof. Gennadiy M. Stoyanovich, Far Eastern State Transport University, Khabarovsk Dr. Kazunori Munehiro, Senior Researcher, Civil Engineering Research Institute for Cold Regions, Sapporo Alexey A. Maslakov, Department of Cryolithology and Glaciology, Faculty of Geography, Lomonosov Moscow State University Dmitry Yu. Nekrasov, Coordinator, PYRN Russia 2018–2020 Dr. Pavel I. Kotov, Department of Geocryology, Faculty of Geography, Lomonosov Moscow State University Prof. Viktor V. Pupatenko, Far Eastern State Transport University, Khabarovsk Prof. Fujun Niu, Chinese Academy of Sciences, Beijing Dr. Stephan Saboundjian, Chair of AFP50, Committee on Seasonal Climatic Effects on Transportation Infrastructure, TRB Prof. Ma Wei, State Key Lab of Frozen Soil Engineering, Gansu Prof. Yuanming Lai, Academician, Chinese Academy of Sciences, Beijing Prof. Qing-Bai Wu, State Key Lab of Frozen Soil Engineering, Gansu Prof. Zhou Guoqing, Vice-president, China University of Mining and Technology, Xuzhou Prof. Adelino Jorge Lopes Ferreira, University of Coimbra Pietro Rimoldi, Professional Civil Engineer, Council member of IGS Prof. Dimitrios Zekkos, University of Michigan, Ann Arbor Prof. Hemanta Hazarika, Kyushu University, Fukuoka Prof. Zhuangzhuang Liu, School of Highway, Chang’an University, Xi’an Prof. Erol Guler, Bogazici University, Istanbul Prof. Heinz Brandl, President of the Austrian Chapter of IGS, Vienna University of Technology

Editorial Committee Dr. Dali Naidu Arnepalli, India Prof. Talal Awwad, Syria Prof. Gokhan Baykal, Turkey Prof. Daniele Cazzuffi, Italy Prof. Krzysztof Czech, Poland Prof. Hamed Farshbaf Aghajani, Iran Prof. Erol Guler, Turkey Ing. Viktor Ganchits, Russia Prof. Wojciech Gosk, Poland

Organizing Committee

Prof. Tatsuya Ishikawa, Japan Prof. Jacek Kawalec, Poland Prof. Jong-Sub Lee, South Korea Prof. Dongqing Li, China Prof. Xu Li, China Prof. Zhuangzhuang Liu, China Prof. Dongdong Ma, China Prof. Kazunori Munehiro, Japan Prof. José Neves, Portugal Prof. P. L. Ng, Hong Kong Dr. Yu Qian, USA Prof. Pietro Rimoldi, Italy Dr. Antonina Sakharova, Russia Prof. Yupeng Shen, China Ing. Arina Sivolobova, Russia Prof. Šarūnas Skuodis, Lithuania Prof. Bagdat Teltayev, Kazakhstan Prof. Ivan Vaníček, Czech Republic Prof. Nicolai Vasiliev, Russia Prof. Yuanjie Xiao, China Prof. Zhaohui Yang, USA Prof. Katarzyna Zabielska-Adamska, Poland Prof. Andrey Zaytsev, Russia Prof. Dimitrios Zekkos, USA Prof. Feng Zhang, China Prof. Askar Zhussupbekov, Kazakhstan

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Preface

The International Scientific Conference “Transportation Soil Engineering in Cold Regions” (TRANSOILCOLD2019) provides an international forum on the latest technologies and research in the field of transportation geotechnics in cold regions. The conference was organized by the Emperor Alexander I St. Petersburg State Transport University, Permafrost Young Researchers Network, Russian University of Transport, Siberian Transport University, Far Eastern State Transport University, Transportation Research Board, Russian Chapter of International Geosynthetics Society (RCIGS) with the support of IGS Technical Committee on Stabilization, Russian Society for Soil Mechanics, Geotechnics and Foundation (RSSMGFE) with the support of ISSMGE Technical Committee TC202 on Transportation Geotechnics, ISSMGE Technical Committee TC215 on Environmental Geotechnics and ISSMGE Technical Committee TC216 on Frost Geotechnics. The “Cold Regions” of the world cover large areas in the northern hemisphere, including Canada, Alaska, Finland, Norway, Sweden, a vast portion of China and Russia and all the northern tier of the USA. The cold regions cover 50% of the world’s total land area. TRANSOILCOLD2019 aims to provide a broader look at the overall problems faced by designers, contractors and infrastructure owners during the planning and building of transport infrastructure in cold regions. TRANSOILCOLD2019 was organized as the follow-up to TRANSOILCOLD symposiums, held in 2013 (Xining, China), 2015 (Novosibirsk, Russia) and 2017 (Gui-de, China). The conference programme included Young Geotechnical Engineers Symposium. The different themes covered in this conference include: – permafrost dynamics in changing climate and under technogenic impact, – green technology in construction and reconstruction of transport facilities for Arctic and cold regions, – design, construction and exploitation of high-speed railway subgrade, – geotechnical problems in permafrost regions, – geotechnical modelling of transport facilities base,

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– use of geosynthetics in construction and reconstruction of transport facilities, – geotechnical problems of underground construction in complex geotechnical conditions, – frost heaving and thaw weakening of subgrade, ballasted subgrade and base of slab track. The Organizing Committee of the TRANSOILCOLD2019 received more than 200 abstracts from 16 countries. Each submitted paper went through an exacting peer review with at least two independent reviewers. Following a thorough review, 109 full papers were selected for submission to Springer series Lecture Notes in Civil Engineering. More than 200 researchers, practitioners and students from all over the world registered to attend the conference. We would like to thank the Organizing Committee members for their support. We would also like to thank all the authors who submitted their papers at this conference and the reviewers St. Petersburg, Russia

Dr. Andrei Petriaev Dr. Anastasia Konon

Contents

Problems of Permafrost, Frost Heave and Thaw Influence of Intra-seasonal Snowfall Deposition, the Peculiarities of Snow Cover Accumulation and Winter Season Temperature Variation on Ground Freezing Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . Denis Frolov Characteristics of Slope Surfaces Deformed by Frost Heaving . . . . . . . . Atsuko Sato and Osamu Hatakeyama The Account of Frost Heave and Thawing Processes When Designing Road Embankments in Cold Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . I. I. Sakharov, V. N. Paramonov and S. A. Kudryavtsev Temperature Deformations of Soil Influencing Transportation Continuity in the Arctic Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. A. Nesterov, A. V. Marchenko, N. K. Vasiliev, Y. G. Kondrashov and A. I. Alhimenko

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Field Experimental Investigations of Freezing and Thawing of Highway Subgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. B. Teltayev, Askar Zhussupbekov, Zh. Shakhmov and E. A. Suppes

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The Destruction of Stabilized Expansive Clays Due to Frost Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kumor Maciej Kordian and Kumor Lukasz

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Experimental Study on Shear Strength Characteristics of Silty Sand Under Freezing and Thawing Conditions . . . . . . . . . . . . . . . . . . . . . . . . Yali Li and Yahu Tian

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Measurement for Permeability of Frozen Soil by Transient Pulse Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tetsuya Tokoro and Tatsuya Ishikawa

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Effects of Permafrost on Earthquake Resistance of Transport Facilities in the Baikal–Amur Mainline Area . . . . . . . . . . . . . . . . . . . . . T. A. Belash and A. M. Uzdin

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Creation of the Massif of Permafrost in Construction Zones of Engineering Structures on Soft Soils . . . . . . . . . . . . . . . . . . . . . . . . . V. I. Moiseev, T. A. Komarova, O. A. Komarova and N. K. Vasiliev

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Research of Ribbed Piles in Permafrost . . . . . . . . . . . . . . . . . . . . . . . . . 105 Naberezhnyi Artem, Kuzmin Georgiy and Savvina Aleksandra The MonArc Project: Monitoring Programme for Foundation Settlements and Initial Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Anatoly O. Sinitsyn, Pavel I. Kotov and Arne Aalberg Soil Dynamics New Approach of Railway Roadbed State Monitoring Using Broadband Seismometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Galina Antonovskaya, Natalia Kapustian and Irina Basakina Analysis of Vibration Measurements on Moving Trains . . . . . . . . . . . . 139 Jonas Majala and Jan Laue Geoecological Aspects of 27 Tons Axle Load Innovative Cars Influence on the Railway Roadbed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Ivan Kozlov, Ksenia Ivanova, Dmitry Kozlov, Vadim Govorov and Evgenii Shekhtman Estimation of Shear Strength and Shear Wave Velocity for Frozen Soils with Various Silt Fractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Sang Yeob Kim and Jong-Sub Lee Problems of Design, Construction and Operation of Transport Infrastructure in Cold Regions Analytical Modeling of the Dynamic Behavior of the Railway Track on Areas of Variable Stiffness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Alexey A. Loktev, Z. T. Fazilova, A. A. Zaytsev and N. L. Borisova The Influence of Ballast Characteristics on Lateral Stability of Railway Track . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Maxim Mylnikov and Alexander Skutin Operation Problems of the Cold Condensate Pipeline in Heaving Soils and Arctic Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Evgeniy Markov, Sergey Pulnikov and Yuri Sysoev

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Producing Sleepers from Modified Wood for Railways in Cold Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Ilya Medvedev, Vladimir Shamaev, Dmitry Parinov and Oksana Shakirova Automated System for Monitoring the Upper Structure of the Railway Track for Extreme Arctic Conditions . . . . . . . . . . . . . . . 205 Daniil A. Loktev and Alexey A. Loktev Traffic Management System for the Northern Latitudinal Railway . . . . 215 Efim N. Rozenberg, V. I. Umansky and M. I. Shmulevich Rails for Low Operating Temperature and High Speed . . . . . . . . . . . . . 221 Evgeny Shur, Alexey Borts and Sergey Zakharov Complex Solutions for Providing Roadbed Stability on Permafrost . . . . 233 Svetlana Zhdanova and Oksana Neratova Intelligent Onboard Train Protection System for the Northern Territories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Efim N. Rozenberg and Vladimir Batraev Transport Construction of the Mainland—Sakhalin Island . . . . . . . . . . 249 Ekaterina Shestakova, Anatolii Novikov, Anatoly Antonyuk and Pavel Kurchanov Analysis of Changes of Track Upper Structure Technical Condition and Its Operation Costs in Regions with Long Winter Period for Different Types of Rail Fastenings . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Vladimir Beltiukov, Andrey Andreev and Anna Sennikova Experiments of Autonomous Vehicles Running at a Test Track, and Future Prospects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 Kazunori Munehiro, Naohisa Nakamura and Masaya Sato Stress–Strain State of Railway Embankment with the Use of Mineral Geoecoprotective Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 Ivan Kozlov The Problems of the Railway Subgrade Construction in the Subarctic Part of the Russian Cryolithozone and the Ways of Their Solution . . . . 295 Evgeny S. Ashpiz Requirements for Tramway Filler Block During Construction in Cold Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Evgenii P. Dudkin and Kirill A. Gmirya Technogenic Hazards of Russian North Railway . . . . . . . . . . . . . . . . . . 311 Isaev Vladislav, Kotov Pavel and Sergeev Dmitrii

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Analysis of Track Condition Based on Application of the Irregularity Length Cumulative Distribution Function . . . . . . . . . . . . . . . . . . . . . . . 321 Gregory A. Krug Study on the Effect of HDPE Stress Absorbing Layer in Preventing Reflective Cracks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Zhonghua Hao, Jiankun Liu and Jian Chang Railway Subgrade Stressed State Under the Impact of New-Generation Cars with 270 kN Axle Load . . . . . . . . . . . . . . . . . . 343 Alexey Kolos, Andrei Romanov, Vadim Govorov and Anastasia Konon Negative Impact of Geological Condition on the Roadbed Structure . . . 353 Natalia Kirillova, Maksim Rymin and Nadezhda Teniriadko Analysis of the Experience of Operation and Scope of Application of Direct Connections to Ensure Passenger Transportation on Regional Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 Alexey Kotenko, Tatiana Malakhova and Timofey Shchmanev Features of Tram Traffic Organization in Permafrost Areas . . . . . . . . . 373 S. A. Doronicheva, M. V. Malakhov, Evgenii P. Dudkin and G. L. Akkerman Analysis of Residual Deformations Accumulation Intensity Factors of the Railway Track Located in the Polar Zone . . . . . . . . . . . . . . . . . . 381 Evgenii Chernyaev, Victoriia Cherniaeva, Lyudmila Blazhko and Victor Ganchits Special Aspects of Railway Roadbed Stability Calculations After Its Strengthening by Electrochemical Treatment . . . . . . . . . . . . . 389 Victor Ganchits, Evgenii Chernyaev, Victoriia Cherniaeva and Nataliia Panchenko Features Transport Planning the Network of Municipal Roads in Northern Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 Pavel Pegin, Alexey Ilyin and Ksenia Semenova Bearing Capacity of High Embankment Clay Soils in Terms of Heavy Axle Load Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403 Alexey Kolos, Andrei Romanov, Evgeniy Shekhtman, Gennadii Akkerman, Anastasia Konon and Artyom Kiselev Research on Frost Protective Layers for Railways . . . . . . . . . . . . . . . . . 413 Vladislav Yurkhanov, Dmitriy Serebryakov, Evgeniy Shavrin and Anastasia Konon

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Design, Construction and Exploitation of Geotechnical Structures Intensive Technology of Construction of Geotechnical Structures in Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 Taisiya V. Shepitko, Svyatoslav Ya. Lutsky, Vyacheslav A. Zabolotny and Igor A. Artyushenko Slope Failure Status and Analytical Results of Slope Stability from Fracture Orientations. Case Study in 3B Highway in Xuathoa Area, Backan Province, Vietnam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 Truong Thanh Phi Pile Testing Regarding ASTM and Kazakhstan Standards . . . . . . . . . . 441 A. S. Tulebekova, Askar Zhussupbekov, Serik N. Nurakov and Ye. Ashkey Effective Structure for Strengthening the Road Embankments on Unstable Mountain Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 A. A. Piotrovich, T. F. Mirzoev and A. N. Magdalinsky Complex Analysis of Bored Piles on LRT Construction Site in Astana . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 Askar Zhussupbekov, Abdulla Omarov, Nurgul Shakirova and Daria Razueva Methodical Approaches for Durability Assessment of Engineering Structures in Cold Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 Tamila Titova, Rasul Akhtyamov, Elina Nasyrova and Alexey Elizaryev The Determination of Soil Cutting Force Applied with Bucketless Bottom Rotor with Account of Speed and Runout . . . . . . . . . . . . . . . . . 479 Serik N. Nurakov, T. Awwad, A. Kaliyev and A. S. Tulebekova Analysis of the Settlement of New Construction Drill-Injection Pile with Broadening at the End in Silty-Clayed Soils . . . . . . . . . . . . . . . . . 487 Mikhail Samokhvalov, Andrei Geidt and Aleksandr Paronko Numerical Analysis Using Elastic–Plastic Soil Model for a Single Pile in Clay Layer to Examine the Effect Surcharge Loading on the Distribution of Skin Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499 T. Awwad, S. Al Kodsi, V. Ulitsky, A. Shashkin and L. Awwad Underground Construction in Cold Regions Ventilation Shafts Freezing Protection Under the Influence of Negative Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 Evgenii Kozin, Dmitrii Burin, Alexander Lediaev, Alexander Konkov, Yuri Filonov and Anatolii Novikov

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Justification of Engineering Solution on Rebuilding Severomuysky Railway Tunnel Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 Simon G. Gendler and Mikhail R. Belov Particularity and Prediction Method of Ground Settlement Caused by Subway Tunnel Construction in Permafrost Area . . . . . . . . . . . . . . . 531 Guangming Yu, Ruixue Ge, Xiankun Zeng, Yingnian Yu, Zhuang Zhang, Xianguo Meng and Yongjun Qin Artificial Freezing Method in Geotechnical and Tunneling Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 Martin Ziegler

About the Editors

Dr. Andrei Petriaev is a senior researcher in the Emperor Alexander I St. Petersburg State Transport University, Russia and the President of Russian Chapter of IGS. Dr Petriaev's research expertise is in geoecology and the geotechnics of railways and road design, with specific focus on the challenges faced in cold and arid regions. He has served as the conference chair for the Transportation Geotechnics and Geoecology conference in 2017, and on the scientific committee for various other conferences.

Dr. Anastasia Konon is an associate professor in Emperor Alexander I St. Petersburg State Transport University, Russia, where she joined in 2005. Dr Konon's research interests are primarily in road and railway engineering, with specific emphasis on the geotechnical challenges faced in cold and arid environmental conditions. She has worked as a technician, researcher and engineer in railway design and geotechnics projects for JSC Russian Railways, and has served as the conference secretary for Transportation Geotechnics and Geoecology conference in 2017, and on the scientific committee for various other conferences.

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Problems of Permafrost, Frost Heave and Thaw

Influence of Intra-seasonal Snowfall Deposition, the Peculiarities of Snow Cover Accumulation and Winter Season Temperature Variation on Ground Freezing Depth Denis Frolov Abstract On basis of the data of winter seasons on snowfalls, thermal regime and peculiarities of snow accumulation regime and according to the calculating scheme with three-layer media heat conductivity problem (snow cover, frozen and thawed ground) and with phase transition on the boundary of frozen and unfrozen ground with daily resolution the estimation of ground freezing depth for the North-East part of European territory of Russia for the period of 1988–2008 was conducted. The Heat balance equation included phase transition energy, inflow of heat from unfrozen ground and outflow to frozen ground, snow cover and atmosphere. The heat flux was calculated on basis of Fourier law as a product of heat conductivity and temperature gradient. The assumption that snow cover consists of different layers deposited by different snowfalls and having different structure and density and heat conductivity depending on its density was taken. The density and heat conductivity of each layer and the whole thickness of snow cover were determined and the regional stratigraphic column for snow cover was compiled and the calculation of ground freezing intensity and freezing depth was conducted. The comparison of estimated with calculating scheme and observed values of ground freezing depth were performed and the correlation of equal 0.76–0.77 of them was stated. Keywords Snowfalls · Snow accumulation regime · Winter air temperature · Ground freezing depth

1 Introduction Thermal regime of winter season and peculiarities of snow accumulation are important factors for ground temperature and freezing depth. According to the data on these processes and on basis of construction norms the depth of freezing and placement of underground pipelines are determined. However, variations in the process of intraseasonal snowfall deposition, accumulation of snow cover and seasonal variations of D. Frolov (B) Geographical Faculty, Lomonosov Moscow State University, Moscow 119991, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_1

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air temperature in relation to mean values lead to variations of ground temperature, variations of ground freezing depth and hazards for underground pipelines. Kudriavcev [1] characterized warming and cooling action of snow cover on the ground depending on snow accumulation regime and on its duration and suggested an equation for estimation of ground freezing depth including snow cover thickness, its thermal properties and amplitude of yearly air temperature oscillations. In the work of Park et al. [2] by means of experiments with ground surface model CHANGE was established, that intensive snowfalls at the beginning of winter season make thermos-isolating snow cover before coming of frost and prevent ground cooling and reduce freezing or increase thawing depth. In the rock ground freezing modelling, Haberkorn et al. [3] the model Alpine3D consisting of the 3D atmospheric processes model coupled with the 1D energy balance model SNOWPACK is used. In our case calculating scheme for ground freezing was constructed on basis of three-layer media heat conductivity problem (snow cover, frozen and thawed ground) with phase transition on the boundary of frozen and unfrozen ground. Heat balance equation included phase transition energy, inflow of heat from unfrozen ground and outflow to frozen ground, snow cover and atmosphere. The heat flux was calculated on basis of Fourier law as a product of heat conductivity and temperature gradient. It was supposed, that temperature changes in each media linearly. For snow cover and frozen and thawed ground the experimentally verified in refrigerated chamber formula of heat conductivity of three-layer media was used. Inconsistency of prediction of ground freezing depth obtained on basis of estimation scheme with the observed ones (possibly in two times) makes it possible to conclude that important role also played the assumption of continuity and uniformity of heat-conducting media properties (of snow cover) and that for snow cover it was assumed the seasonal mean values of density and heat conductivity. Also important role plays relation snow cover heat conductivity on its density, structure and texture. In reality snow cover is not a continuous and uniform media but consists of layers with different structure and density. Consideration of meteorological data of air temperature, precipitation and snow thickness and snowfall intensity on the nearest meteorological station makes it possible to defined density and heat conductivity of snow cover and compile the regional stratigraphic column for snow cover and to conduct the calculation of ground freezing intensity and freezing depth more precisely.

2 Materials and Methods On basis of meteorological data on air temperature, precipitation and snow cover thickness extracted data on deposition and intensity of snowfalls at the nearest meteorological station Narayan-Mar [4] (see distribution on Fig. 1a). Generalized stratigraphy columns are compiled for this region for winter seasons 1990/91–2015/16 like in [5, 6] (see Fig. 1b). On the basis of relation of snow heat conductivity on density

Influence of Intra-seasonal Snowfall Deposition …

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Fig. 1 a Average number of snowfalls of particular intensity according to data of meteorological station Narayan-Mar for 1988–2008, b generalized stratigraphic column of snow cover for meteorological station Narayan-Mar for 1988–2008, c variations of winter season observed and estimated ground freezing depth for meteorological station Narayan-Mar in 1988–2008

according to Pavlov [7] formula the estimation of heat conductivity of separate snow layers was conducted. According to formula of heat conductivity of multilayer media λ = x

x1 λ1

1 + ··· +

xn λn

(1)

And on basis of information on snow layers, the ground freezing depth was calculated. The calculations of freezing of the covered by the snow cover ground in winter period on basis of daily data on air temperature and snow thickness and heat conductivity of snow cover allow estimating the rate of movement of ground freezing

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interface during this winter period. The rate of movement of ground freezing interface can be expressed with the formulas. The equation of heat balance can be written as: F1 = cLV + F2 ,

(2)

is heat outflow through snow cover and frozen ground from ground freezing interface to the atmosphere (W/m2 ); cLV heat value for phase transition in the ground, c—ground moisture content (1– 4 kg/cm*m2 ), (last value correspond to full filling of porous by water for light clay with density 2000 kg/m3 and porosity coefficient 0.617 [8]), L—energy of H2 O phase transition (335 kJ/kg), V —rate of movement of ground freezing interface (cm/s); F 2 heat outflow for cooling of thawed ground in front of ground freezing interface (W/m2 ). F1

Heat flux is expressed according to Fourier law by means of temperature gradient and heat conductivity as F = λ (grad T ). Heat conductivity and heat flux through combination of two media (snow and frozen ground) according to [9] can be expressed as: F1 = λ

T T Tair =  = xfg l xs hs x + + fg λs

λfg

λs

(3)

λfg

here T air air temperature, hs and l fg snow cover thickness and ground freezing depth, and λs and λfg heat conductivity of snow and frozen ground. It was supposed, that on the depth of 10 m in ground there is a point of zero annual temperature oscillation with temperature value T 0 about 3 °C. That is why F2 = λthg

T T0 = λthg x 10 − lfg

(4)

Here λthg is heat conductivity of thawed ground. For validation of three-layers-calculating-scheme the experiment of one direction freezing of covered with snow sand sample was conducted in refrigerated chamber under the action of negative temperatures. The intensity of freezing and rate of movement of phase transition front were determined and compared with obtained by calculating scheme values. For this reason, the dry sand sample with the mass of 5.2 kg, 1.35 g/cm3 density and less than millimeter grain size was placed in plastic volume of 14 * 14 * 30 cm. One liter of distilled water was also added into the sand in order to become its’ moisture content maximal and equal to 20%. The volume with wet sand was placed into heat isolating cover for one direction freezing and thermal

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probes on the levels −20, −10 and 0 cm from the upper sand surface level were also placed. The installation was placed in the refrigerated chamber with negative temperature of −5 °C. As upper sand surface was cooled down, the coarse-grained snow with initial density of 0.3 g/cm3 was placed on the top of sand and thermal probe on the level +5 cm from the upper sand surface was placed close to the upper outer snow surface. In a while of cooling of the installation the phase transition on the lower snow– upper ground surface happened. Further at assumed heat losses of sample at one direction freezing (1 J/s) the calculated time of freezing of the whole ground sample was 90 h. In reality, the phase transition in the ground sample finished in 84 h. This could be explained by not accounted heat losses through the sidewalls of the installation. Therefore, the three-layers-calculating-scheme estimations were validated with experimental observations.

3 Results Calculations of the ground freezing depth were done according to the constructed calculating scheme on basis of heat conductivity Stephan problem with multilayer heat conductivity. For this reason on basis of knowledge about winter snowfalls’ frequency and intensity the generalized snow stratigraphy column for each winter season were compiled and the heat conductivity of the multilayer system was determined. Calculations were done with the step-size of one day. For initial conditions, it was supposed that frozen ground thickness lfg was equal 0.5 cm. For each time step (for each day) the rate of movement of freezing interface V and the value frozen ground thickness lfg for the next day (time step) were calculated. According to [8] averaged heat conductivity of thawed and frozen ground was assumed to be equal to 1.4 and 1.8 W/m °C correspondingly. The results of calculations by described estimation scheme determined general consistency of calculated ground freezing depth values with the observed ones (see Fig. 1c). The correlation coefficient is equal to 0.76–0.77, which is quite good for such simple calculation scheme. The work is done in a frame of state topic AAAA-A16-116032810093-2 «Mapping, modelling and assessment of risk of hazardous natural processes».

References 1. Kudryavtsev VA (1954) Temperature of the upper horizons of permafrost thickness within the USSR. Akad. Nauk SSSR, Leningrad 2. Park H, Fedorov AN, Zheleznyak MN, Konstantinov PY, Walsh JE (2014) Effect of snow cover on pan-Arctic permafrost thermal regimes. Clim Dyn 9–10(44):2873–2895

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3. Haberkorn A, Wever N, Hoelzle M, Phillips M, Kenner R, Bavay M, Lehning M (2016) Distributed snow and rock temperature modelling in steep rock walls using Alpine3D. Cryosphere Discuss. https://doi.org/10.5194/tc-2016-73 4. Specialized data for climatic research. http://aisori.meteo.ru/ClimateR 5. Golubev VN, Petrushina MN, Frolov DM (2017) Snowfall events as a factor of snow cover’s stratigraphy formation. In: Lupo A (eds) The 2nd international electronic conference on atmospheric sciences, vol 2 (2017) 6. Golubev VN, Petrushina MN, Frolov DM (2008) Winter regime of temperature and precipitation as a factor of snow-cover distribution and its stratigraphy. Ann Glaciol 49:179–186 7. Pavlov AV (2008) Cryolithozone monitoring. Academician Publishing House, Novosibirsk 8. Trofimov VT (2005) Soil science. MSU Publishing, Moscow 9. Mikheev MA, Mikheeva I (1977) Fundamentals of heat transfer. Energiya, Moscow

Characteristics of Slope Surfaces Deformed by Frost Heaving Atsuko Sato and Osamu Hatakeyama

Abstract Many deformation incidents of cut slopes due to the repetition of freezing and melting in cold-district regions have been reported. Technologies to prevent incidents or mitigate the effects are required to be established. However, it is not easy to judge whether the deformation of a slope surface is due to frost heaving because experiences and technical evidence are needed for the judgment. The frost heaving phenomenon is caused when the three conditions of temperature, soil property, and moisture are met. The frost susceptibility of a constructed area can be judged when these conditions are investigated in detail. However, it is not realistic to investigate all areas in detail, which are not clear at this moment. Therefore, data on slope surface conditions, meteorological conditions, and other required conditions of a lightweight constructed slope surface, which suffered extensive damage due to frost heaving and showed the frost heaving phenomenon clearly in Hokkaido, northern Japan, were obtained for the study. The results of the study clarified the following matters: (1) irrespective of the snow coverage, deformation occurs due to frost heaving in a lowtemperature area; (2) snow coverage is small on a slope surface with a slope gradient of about 1:1.2 and heat insulation by the snow is not expected; (3) the direction of the slope surface may affect the frost heaving generation, and slope surfaces facing the northwest or southeast direction may cause frost heaving. Keywords Frost heaving · Slope surfaces · Deform

1 Introduction Many deformation incidents of cut slopes due to the repetition of freezing and melting in cold-district regions have been reported. Technologies to prevent the incidents or mitigate the effects are required to be established. The Study Group on the Survey and Design Methods of Frost Heaving Countermeasure Works of the Hokkaido Branch of Japanese Geotechnical Society studied the matters from June 2011 to A. Sato (B) · O. Hatakeyama Civil Engineering Research Institute for Cold Region, Sapporo, Japan e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_2

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March 2015. The Group showed investigation approaches to select frost heaving countermeasure works of slope surfaces, criteria to select the construction methods, and design methods to prevent frost heaving and mitigate the effect [1]. The investigation on frost heaving consists of brief investigations and detailed investigations. Confirmation of the deformation of peripheral structures is indicated as a part of the brief investigation. However, it is not easy to judge whether the deformation of slope surface is due to frost heaving because experience and technical evidence are needed for the judgment. Moreover, the frost heaving phenomenon is caused when the three conditions of temperature, soil property, and moisture are met [2]. The frost susceptibility of the constructed area can be judged when these conditions are investigated in detail. However, it is not realistic to investigate all areas in detail, which are not clear at this moment. Therefore, it was considered that the conditions of slope surfaces and meteorological phenomena of areas which suffered large damage due to frost heaving in Hokkaido located in the north of Japan will contribute to the selection of the investigation areas to some extent, which will reduce the expense and time required for the investigation.

2 Investigation Method Hokkaido Development Bureau, Ministry of Land, Infrastructure and Transport, developed the accident prevention checklist for national highways (hereafter referred to as the “checklist”) to maintain and manage the jurisdiction district. The checklist has been used to check and record deformation, which is considered to be one of the factors leading to a disaster, and to judge the necessity and urgency of countermeasure works. This investigation was performed from 2006 to 2016, selecting a lightweight slope frame structure to judge whether frost heaving affects the deformation of the structure from photographs of the checklist without performing a field investigation. The lightweight slope frame structure was selected as it is possible to be affected by frost heaving from various structures built by such construction methods as ground-anchorage work, rock-mass reinforcement work, revetment work, reinforcement work, basket work, slope framework, spray work, and drainage work. The slope with the lightweight slope frame structure was deformed as shown in Fig. 1. The deformation was caused as anchor pins were drawn out by frost adhesion and heaving. Judgment by these photographs is easy. Therefore, deformation data of lightweight slope frame structures were compiled for the investigation. Then, the deformation of the lightweight slope frame structure shown in the checklist was judged as to whether it was caused by frost heaving or not. Moreover, the slopes, surface conditions, such as the height, slope angle, and direction, and meteorological conditions, such as tree planting, spring water, air temperature, and snow coverage, were compared for structures that showed deformation caused by frost heaving.

Characteristics of Slope Surfaces Deformed by Frost Heaving

(a) Steel slope frame

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(b) Precast concrete slope frame

Fig. 1 Deformation of slope by frost heaving

Also, the lightweight slope frame structure is expected as a foundation work to prevent erosion by rain and to function for tree planting. Lightweight slope frame structures made of precast concrete, steel, wire net, plastic, etc. are constructed to stabilize slope surfaces, and have been used widely in Japan. However, in a cold district like Hokkaido, it is required to pay sufficient attention for the application because there are instances of disaster as described in [3] above, and instances of construction of lightweight slope frame structures have decreased dramatically recently.

3 Investigation Results 3.1 Type of Lightweight Slope Frame Structures Checklists of the Hokkaido Development Bureau indicated that a total of 58 lightweight slope frame structures made of steel, precast concrete, resin, and wood showed deformations due to frost heaving. The type of deformed lightweight slope frame structures is shown in Fig. 2. The number of the deformed structure type is in descending order of steel, precast concrete, resin, and wood. The type of frame construction that tends to cause the deformation was not identified because the actual number of installations was unclear. However, it is considered that the deformation of a lightweight slope frame structure of any kind of material is caused by frost heaving. Also, investigated checklists were recorded in 2006–2008, revealing that the deformations of lightweight slope frame structures were already caused before the recording times. Because the construction year of a lightweight slope frame structure is unknown, the elapsed time from the construction to deformation cannot be calculated. However, a study by Ueno et al. [4] showed that the ground surface rises by freezing and sinks by melting, but the residual displacement accumulates because the raised surface does not come back to the level it was at before frost heaving. This

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Fig. 2 Type of deformed lightweight slope frame structures

phenomenon occurred on lightweight slope frame structures. Namely, lightweight slope frame structures raised by frost heaving and sunk by melting to some extent, but, because the surface does not come back to the original level, the elapse of time caused the lightweight slope frame structure to rise above the slope surface due to the accumulation of residual displacements. Because the factors of the temperature, soil property, and moisture that affect frost heaving are not considered to change largely, the deformation phenomenon is considered to occur immediately after construction.

3.2 Height to Develop the Deformation The height at which the lightweight slope frame structures deformed due to frost heaving is shown in Fig. 3. The lightweight slope frame structures deformed at a comparatively low level of less than 10 m. The lower part of the slope surface is considered more vulnerable to deformation due to frost heaving than the upper part Fig. 3 Height of the deformed lightweight slope frame structures

Characteristics of Slope Surfaces Deformed by Frost Heaving

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because the moisture flows to the lower part from the upper part. Seventeen (onethird of the whole) checklists describe the back face geomorphological information of the slope surface as the foot part of a plateau, forest, or catchment basin. Such topographies easily hold moisture in such forms as rain in the back face of the slope surface, and the held moisture can serve as a supply source for frost heaving.

3.3 Inclination of the Slope The inclination of the slopes of lightweight slope frame structures deformed by frost heaving are shown in Fig. 4. The inclination of approx. 90% of the whole slopes is 1:1.2 or less. The Hokkaido Development Bureau specifies the standard slope inclination of the cut land of 1:1.0 to 1:1.2 except for ground with spring water or a landslide [5]. The slope surfaces for which the lightweight slope frame structures were constructed to satisfy this standard.

3.4 Direction of the Slope Surface Twenty-four of the investigated checklists describe the direction information of the slope surfaces. The directions of the slope surfaces of these lightweight slope frame structures are shown in Fig. 5. Slope surfaces facing northwest and southeast show much deformation, and slope surfaces facing northeast and southwest show little deformation. For other deformed slope surfaces confirmed from now on, the direction of the slope surfaces will be investigated to confirm this tendency.

Fig. 4 Inclination of the slope of the deformed lightweight slope frame structures

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Fig. 5 Direction of the slope surface of the deformed lightweight slope frame structures

3.5 Meteorological Conditions Because the meteorology was not observed in the investigation area, meteorological data were not described in the checklists. Considering that meteorological conditions have a significant effect on frost heaving, data on the air temperature and snowfall near the investigation areas were collected from AMEDAS [6] of the Japan Meteorological Agency. Because the deformation of the lightweight slope frame structures was confirmed in the checklists from 2006 to 2008, the meteorological data from 1998 to 2007, including the data for ten years until the deformation was confirmed, were collected. The maximum and minimum of the air temperature and snowfall are obtained from the data near the investigated areas in this period as shown in Table 1. The lowest air temperature was −30.3 °C in the cold area in Hokkaido. The snow coverage was data observed on flat ground ranging from 27.9 to 249.8 cm. The deformation of lightweight slope frame structures occurred in areas with considerable snow coverage. Table 1 Meteorological conditions

Minimum

Maximum

Air temp. (°C)

−30.3 (Shumarinai)

−13.3 (Soya cape)

Snow coverage (cm)

27.9 (Nemuro)

249.8 (Shumarinai)

Characteristics of Slope Surfaces Deformed by Frost Heaving

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3.6 Places of Constructed Lightweight Slope Frame Structures Deformed by Frost Heaving Places of constructed lightweight slope frame structures deformed by frost heaving are shown in Fig. 6 for each structure material. Also, the main meteorological characteristics of each area in Hokkaido are shown in Fig. 7 [7]. Lightweight slope frame structures suffered from damage due to frost heaving mostly in low-temperature areas in Hokkaido, and 80% and 20% of the damage occurred in light snow areas and heavy snow areas, respectively. This difference is due to the heat insulation effect of snow, that is, in the heavy snow area, the snowy heat insulation makes the frost penetration depth thinner and the frost heaving less. Lightweight slope frame structures made of steel suffered damage equally in the light and heavy snow areas. Lightweight slope frame structures made of precast concrete suffered damage in the low temperature and light snow areas shown in Fig. 5. Because the number of constructions for each structure material is unknown, it is not clear whether the deformation is due to the number of constructions or due to the meteorological conditions. Fig. 6 Places where lightweight slope frame structures deformed

Hokkaido

Japan

Fig. 7 Main meteorological characteristics of each area in Hokkaido

16 Table 2 Maximum snow coverage depth and the frost penetration depth for each slope inclination

A. Sato and O. Hatakeyama Inclination

Snow coverage

Frost penetration depth

1:1.2

20

58

1:1.5

40

38

1:1.8

60

17

Flat ground (snow removed)

0

79

This investigation showed that the deformation of the lightweight slope frame structures also occurred in heavy snow areas. It is shown that the snow coverage exceeding about 20 cm suppresses the frost penetration depth due to the snowy heat insulation effect [8]. The snow coverage on a gentle slope is deep, and that of a steep slope is shallow. Authors measured the slope inclination, snow coverage depth, and frost penetration depth in the Tomakomai area [9]. The investigation results show that the inclination of a slope to cause a snow coverage depth of approx. 20 cm, which can expect the snowy heat insulation effect, is 1:1.5, and that a steeper slope causes less snow coverage depth, leading to deeper frost penetration. Furthermore, Table 2, which shows the data measured by another organization [10], indicates that a steep slope exceeding 1:1.2 causes deeper frost penetration depth. Table 1 is considered to not be appropriate for the slope exceeding the inclination of 1:1.2 because the show coverage was measured on flat ground. Also, the slope inclination of 8 out of the 11 heavy snow areas, of which slope inclination is known, is steep, exceeding 1:1.2. Even in the heavy snow area, if the slope is steep, the snow coverage is light, and the frost penetration is deep, which may cause the deformation by frost heaving. Because the frame height of lightweight slope frame structures is comparatively low, it is considered that the slope inclination and snow coverage are related. However, the frame height of the ground-anchorage work and rock-mass reinforcement work, which are constructed in an on-the-spot concrete frame, is high, and the snow may accumulate in the frame. The drainage work is constructed on a flat surface, which is a structure that also easily accumulates snow. As explained above, depending on the structure, the slope inclination is not the prime concern.

4 Conclusions This report, using the checklists, discusses areas where the deformation of lightweight slope frame structures is developed. The results show that irrespective of the amount of snow coverage, deformation due to frost heaving occurred in Hokkaido. Moreover, heat insulation by the snow coverage is not expected for an excavation slope of approx., 1:1.2 standard inclination. Furthermore, the direction of the slope surface may also affect frost heaving; that is, the slope surface of northwest and southeast directions may cause frost heaving.

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Acknowledgements I most gratefully acknowledge the people at the Hokkaido Development Bureau of the Ministry of Land, Infrastructure and Transport who provided data from the accident prevention checklists of national highways for this study.

References 1. Hokkaido branch of the Incorporate Foundation, Japanese Geotechnical Society (2016) Study group on investigation and design methods of frost heaving countermeasure works, investigation and design manual of the measures against the frost heaving of slopes (proposal) 2. Japanese Geotechnical Society (1982) Soil freezing—control and application—Soil Foundation Engineering Library, pp 7–8 3. Hokkaido Development Bureau (2018) Road design procedure, I-4-28. Hokkaido Development Bureau 4. Ueno K, Dahu R, Suzuki T, Yamashita S (2008) Behavior of sodding slope in freeze-thaw process, observation (2). In: 43rd geotechnical-engineering research presentation meeting, pp 989–990 5. Hokkaido Development Bureau (2018) Road design procedure, I-3-19. Hokkaido Development Bureau (2018) 6. Past Meteorological Data, Japan Meteorological Agency, https://www.data.jma.go.jp/obd/ stats/etrn/index.php, 7 Dec 2018 7. Sapporo Technical Office, Hokkaido Branch Office, Japan Highway Public Corporation (2003) Recent technical efforts for frost heaving countermeasures of Hokkaido Highways, Lilac No. 15, p 1 (2003) 8. Tsuchiya F (2001) Effect of Climate change on frost penetration depth and feature of soil freezing. In: Symposium on soil freezing and indoor frost heaving experiment method, the Japanese Geotechnical Society 9. Sato A, Nishimoto S, Suzuki T (2011) Relationship between the slope inclination, snow coverage, and frost penetration depth. In: 29th Nippon Road meeting 10. Hokkaido branch of the Incorporate Foundation, Japanese Geotechnical Society, Study Group on Slope Damages by the Frost Heaving and Countermeasures (2000) Guideline on slope damages by the frost heaving and countermeasures

The Account of Frost Heave and Thawing Processes When Designing Road Embankments in Cold Regions I. I. Sakharov, V. N. Paramonov and S. A. Kudryavtsev

Abstract Construction of railway embankments in cold regions is associated with a need to take into account not only changes in temperature but also deformations of embankments and their subsoils during freezing and thawing. If in case of aboveground structures (elements of buildings and transport facilities) temperature changes are accompanied, as a rule, by relatively small linear deformations, for soils—deformations of frost heave and thawing, associated with freezing and thawing due to phase transformations of water, significantly exceed temperature deformations in elements of a structure. Therefore, calculation of deformations of embankments and their subsoils increases complexity of designing these sites by an order. The method developed by the authors for the finite-element solution of such problems consists of two stages: calculation of temperature fields and calculation of the stress–strain behavior of soil and structures located on it. The article pays attention to inevitable heterogeneity of temperature fields for linear structures located in the cryolithozone, oriented in the latitudinal direction, which causes uneven deformations of frost heave and thawing. Keywords Freezing · Thawing · Insolation

1 Introduction Thawing of soils in the warm season is attributable to positive air temperatures. However, the action of solar radiation is the most important factor provoking thawing. If, for example, on the coast of the Arctic ocean, solar radiation cannot be taken into

I. I. Sakharov Saint-Petersburg State University of Architecture and Civil Engineering, Saint-Petersburg, Russia V. N. Paramonov (B) Saint-Petersburg State Transport University, Saint-Petersburg, Russia e-mail: [email protected] S. A. Kudryavtsev Far Eastern State Transport University, Khabarovsk, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_3

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account due to the low standing sun and frequent clouds, in the southern areas of the permafrost areas such an account is often absolutely necessary. For industrial and civil buildings the account of the solar radiation helps to explain some emergencies. Therefore, in one of the authors’ articles it was shown how the shadowing of the northern section near the school building led to accumulation of frozen soil, which thawing at the start of heating of the building resulted in large settlements of soils and pile foundations near the walls of the northern section of the building [1]. For long linear structures, which represent embankments of railways and roads, the effect of insolation is especially evident for the sites traced in the latitudinal direction. These are, primarily, the railway tracks of the Trans-Siberian Railway and the “Amur” highway. For these structures, southern parts of embankments and adjacent areas are subjected to significantly greater warming than the northern parts. This uneven heating leads to more intensive thawing and, accordingly, to larger settlements of southern parts of cross-sections, which cause inclination of embankments. The calculations of the effects of solar radiation are hardly used in practice. The necessity to take into account the uneven insolation in predicting deformations of embankments at thawing of soil is demonstrated on a real example.

2 Calculation of Freezing and Thawing of an Embankment and Its Subsoil Taking into Account Solar Radiation Here are the results of calculations of temperature fields and deformations across the road embankment with or without taking into account the action of insolation. The height of the road embankment is 3 m, it is made of non-heaving soil, erected on soils with a coefficient of thawing 0.05. The calculations were performed for a period of two years with a 1-month step for the climatic conditions of the village of Skovinino. The calculation started from October—the first month with negative air temperature. The finite-element scheme of the embankment with its subsoil is shown in Fig. 1. The software complex “Termoground” was used for computational evaluation of the influence of insulation, which features and the algorithm for solving the problems are described in the paper [2–4]. Monthly total solar radiation was set according to clauses 8 and 9 of SP 131.13330.2012 “Construction climatology”, the updated version of SNiP 23-01-99 [5]. Cloudiness in the reserve was not taken into account. Fig. 2 demonstrates contours and diagrams of temperatures in three sections of the cross-section after two years of operation before the beginning of the winter period without taking into account the action of solar radiation. As it can be seen from the figure, the temperature distribution is symmetrical, which should lead to symmetry of deformations caused by freezing and thawing. This situation is typical for linear structures traced in the meridional direction.

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Fig. 1 Finite element scheme

Fig. 2 Temperature distribution in the system “embankment—foundation” at the end of the warm period without taking into account the action of solar radiation

When the embankment is oriented in the “west-east” direction, the southern part of the cross-section experiences significantly more heating than the northern part (Fig. 3). As it can be seen from the figure, the temperature difference on the surfaces of the slopes reaches 13°. This temperature difference at the end of the thawing period leads to a substantially greater thickness of the thawed layer in the southern part of the cross-section (Fig. 4). Thus, outside of the embankment the difference in the thickness of the thawed zone reaches almost 1.3 m. Such a difference naturally leads to different displacements of the southern and northern parts of the cross-section (Figs. 5 and 6).

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Fig. 3 Asymmetric radiation. Contours and temperature distributions of soil at the end of the warm period of the year

Fig. 4 The areas of soil thawing in the subsoil of the embankment at the end of the warm period after 2 years of operation. Frozen ground is shown in blue. The thickness of the thawed soil layers is shown in meters

Fig. 5 The graph of total displacement of the surface of the cross-section after 2 years of operation, m

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Fig. 6 Displacements of various points of the cross-section for a 2-year period of operation

3 Conclusions Therefore, uneven displacements of the embankment caused by their various exposures without taking any other structural measures are inevitable, that leads to deformations of rail tracks or solid coatings of roads. In order to eliminate differential deformations of embankments, which accumulate during operation, it is possible to propose the following methods: 1. Reduction of influence of solar radiation, which can be achieved by thermal insulation of the southern parts of embankments. 2. Reduction of thawing settlements, for which it is necessary to provide laying materials with low coefficients of relative thawing in the thawing zones. In case of the existing roads, the latter method can be implemented by injection of special mixtures into the thawing zones.

References 1. Paramonov MV, Sakharov II, Paramonov VN (2015) Accounting for non-one-dimensionality of frost heaving in the numerical implementation of spatial problems. In: Proceedings of second international symposium TranSoilCold-2015, pp 117–120 2. Paramonov VN, Sakharov II, Kudriavtcev SA (2016) Forecast the processes of thawing of permafrost soils under the building with the large heat emission. In: MATEC web of conferences

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2016, “15th international conference “topical problems of architecture, civil engineering, energy efficiency and ecology—2016”, TPACEE 2016” 3. Ulitskii VM, Sakharov II, Paramonov VN, Kudryavtsev SA (2015) Bed—structure system analysis for soil freezing and thawing using the Termoground program. Soil Mech Found Eng 52(5):240–246 4. Paramonov MV, Sakharov II (2013) Mathematical modeling of thermal and deformation processes in problems of freezing and thawing of soils. In: Proceedings of 5th international geotechnical symposium. Geotechnical engineering for disaster prevention and reduction. IGH5, Incheon, 22–24 May 2013. Incheon, South Korea, pp 122–127 (213) 5. SP 131.13330.2012 «Construction climatology». Updated version of SNiP 23-01-99

Temperature Deformations of Soil Influencing Transportation Continuity in the Arctic Region A. A. Nesterov , A. V. Marchenko , N. K. Vasiliev , Y. G. Kondrashov and A. I. Alhimenko

Abstract Phase transformations of ice in seasonally frozen soils are an inalienable part of the Earth’s cryosphere and affect the balance of the external heat of our planet. These processes depend on natural and technogenic changes in the environment. That is why for the design of engineering structures (roads and railways, quay walls, etc.) built in the Arctic world regions, it is necessary to have a complete understanding of the formation mechanism of the stress–strain state of such soils in a wide range of thermal loads. The study of the nonstationarity of ice, as an important component of the considered medium, is an actual problem. New method for measuring the temperature deformations of frozen soils using fiber-optic Bragg grating sensors can serve as a solution. In the course of the experiments, cylindrical samples of previously frozen soils saturated with water of different salinity were tested. Measurements of the thermal deformations of frozen soil samples were performed in the cold laboratory in the temperature range between 0 and −12 °C. Fiber Bragg gratings strain and temperature sensors were used to measure the deformation and temperature inside the samples. A number of tests with the samples prepared from Kaolin and Cambrian clay saturated with freshwater, and prepared from fine and silt sand saturated with fresh or saline water, were performed. Thermal deformations of the samples are analyzed depending on the cyclic changes of their temperature. Keywords Thermal expansion · Frozen soil · Ice · Sand · Clay · Fiber-optic sensors · Arctic region A. A. Nesterov (B) · A. I. Alhimenko Peter the Great Saint-Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 Saint-Petersburg, Russia e-mail: [email protected] A. V. Marchenko University Centre in Svalbard, N-9171 Longyearbyen, Norway N. K. Vasiliev JSC Vedeneev VNIIG, Gjatskaya 21, 195220 Saint-Petersburg, Russia Y. G. Kondrashov KPIF AO Atomenergoproekt, Molodezhnaya 9, 307251 Kurchatov, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_4

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1 Introduction A need for mining, hydraulic engineering, transport, industrial, and other types of construction causes development of frozen soil mechanics, the purpose of which is to develop methods for determining the stress–strain state of frozen soils as a result of thermal or mechanical effects on them in man-made and cryogenic processes. Without knowledge of thermodynamics, heat and mass transfer, physicochemical, mechanical, and structural processes (cycles of freezing-thawing) of frozen soils, it is impossible to develop evidence-based recommendations for the forecast of their changes and purposeful management in connection with the economic development of the Arctic world regions. One of permafrost study domains is geocryology, that is geological support of design, construction, and operation of engineering structures in the cryolith zone for the justification and selection of the most reliable and economic methods for permafrost area development. The processes of frozen soil interaction and structures have paramount importance at all stages of design in the northern building climatic zones. Main production requirement in these conditions is the conclusion of engineering-geocryological surveys and study (laboratory and field) composition, cryogenic structure, physical and mechanical properties of frozen soils and ice as the basis of engineering structures. The foundations behavior forecast is based on results of qualitative and quantitative research of interaction freezing breeds processes and engineering constructions. Experimental investigations of thermal deformations of frozen soils started in the 1930s [1]. A complex nonlinear character of the deformations due to the cooling was ascertained later by [2–6]. Thermal deformations of frozen soils have abnormal properties (expansion due to cooling and contraction due to heating) in a certain range of temperatures due to the presence of unfrozen or bound water in frozen soils [7–10]. Properties of the bound water in cryogenic soils are discussed in the analytical review [11]. Negative values of the coefficient of thermal expansion are explained by the gradual freezing of the bound water during the soil cooling [12, 13]. Several methods of determining the amount of unfrozen water in frozen soil are known: the method based on measurement of the thawing temperature [14], the method of measuring the amount of heat for heating the soil and melting the ice in a sample [15], and the calorimetric method [16]. All of these methods involve determining multiple deliverables, are time-consuming, and are not accurate enough. The method for determining of soil deformations with dial indicators does not have sufficient measurement accuracy [6]. In the present paper, we describe the method and the results of direct measuring of thermal expansion/contraction of frozen soil samples with fiber Bragg gratings (FBG) strain and temperature sensors. The experiments are performed with soil samples with different grain-size distribution, water saturation, and salinity. Earlier, this method was used to investigate thermal expansion of saline ice [17].

Temperature Deformations of Soil Influencing Transportation …

27

2 Instrumentation FBG sensor is a periodic grid with 40,000 cells burned by two laser beams inside the fiber with diameter of 9 µm. The grid length is 1 cm. Each FBG sensor reflects the light signal of a certain wavelength, depending on the grid characteristics, tension, and temperature of the fiber. The incoming light signal is generated in the optical fiber by the source LED in the spectral range 1,500–1,600 nm. The wavelengths reflected by the FBG sensors are registered and analyzed by a spectrometer. To register changes inside a calibration device, a constant temperature is maintained in one of the sensors. The spectrometer, calibrator, and analyzer of the incoming optical signals are combined in one unit with four channels designed and manufactured in the company Advanced Optics Solutions GmbH (Dresden). Every channel of the unit can transfer information from 16 FBG sensors embedded in the same fiber. FBG thermistor string and strain sensor are shown in Fig. 1. Fiber cable with FBG temperature sensor is protected from mechanical deformations by thin metal tube of 1 mm diameter. The FBG thermistor string includes 12 FBG sensors embedded in the same fiber with 1 cm distance between neighbor sensors. The FBG thermistor string is protected from mechanical deformations by thin metal tube of 1 mm diameter and 25 cm length. The thermistor string is welded with optical fiber protected by blue plastic. The accuracy of temperature measuring and nominal resolution is correspondingly equal to 0.4 and 0.08 °C. Strain sensor is embedded in the middle part of the fiber protected by transparent plastic with working length about 20 cm. The fiber inside transparent plastic is going through the screw and welded to fiber cable protected by yellow plastic. The strain sensor is mounted on a sample and attached using two screws and bolts. The resolution of the strain sensors is 10−6 , and the accuracy is 5 × 10−6 . The change of the wavelength (λ) of the light reflected by the Bragg grating is proportional to the fiber extension (L/L) and the change of the fiber temperature (T ): Fig. 1 FBG thermistor string with blue plastic housing of the fiber and strain sensor with yellow plastic housing of the fiber

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L λ = GF · + TK · T λ L

(1)

where GF = 0.719, “calibration factor”; TK = 5.5 × 10−6 , “thermal elongation factor”; L is the reference length of the fiber; λ is the reference length of the light reflected by the Bragg grating. The value of λ is measured by the spectrometer. From Eq. (1), it follows that temperature changes of the fiber T should be known for the calculation of the fiber strain L/L. In the experiment, the temperature of the strain sensor was measured by the FBG temperature sensor. The FBG thermistor string was installed to measure temperature inside the soil sample.

3 Experiments The soil samples were installed within the metal frame used for the mounting of the fiber with FBG sensors (Fig. 2). The fiber with FBG strain sensor was fixed between the metal frame and the steel slab, lying on the surface of the sample. The vertical screws exclude possible horizontal displacements of the slab along the sample. It allows to avoid the complicated procedure of fixing the sensors on the sample itself [14] and simplify the mounting of FBG sensors. The distance between the slab and the frame decreases when the sample elongates. In this case, the strain sensor indicates contraction. In case when the sample becomes shorter, the strain sensor indicates expansion. The sample strain is calculated according to the strain sensor reading as follows:

Fig. 2 a View of the tested sample, b the rig for the tests

Temperature Deformations of Soil Influencing Transportation …

ε=

29

L s L s L =− Ls L Ls

(2)

where L is the initial distance from the frame to the sample surface, and L s is the initial length of the sample. Samples of different porosity, density, and water content were prepared in the cold laboratory of the University Centre in Svalbard (UNIS). The samples had the form of thick-walled cylinders 20 cm high, with the outer diameter 13 cm and the inner diameter 2 cm (Fig. 2a). The physical characteristics of the soils are presented in Table 1. The water content of the sand samples was preset as equal to 15% and for clay samples, 35.5%. The water saturation ratio S r for sand samples was equal to 0.72– 0.86 and for clay samples, 0.90–0.96. Saturation was performed using freshwater or seawater with salinity of 34.3 ppt. For clay samples, the densities of them were approximately equal. The fine and silt sands had the characteristics presented in Table 2. The fine sand was considered to have no less than 75% content of particles >0.1 mm by weight; the silt sand had less than 75% content. For sand sifting, the sieves of international standard ASTM and the vibrating table Retsch AS 200 were used. The soil samples were preliminarily cooled before testing: the sand samples to 0 °C and the clay samples to −5 °C. Then, each sample was placed in the cold room, and the FBG strain sensor and thermistor string were mounted on the sample. All electronic devices, the LED source, the spectrometer, and the PC were installed Table 1 Characteristics of the tested soils Type of soil

Water content, W (%)

Type of water used for saturation

Density (g/cm3 )

Void ratio, e

Saturation factor, S r

Fine sand

15.0

Fresh

2.04

0.544

0.76

Silt sand

15.0

Saline

2.13

0.479

0.86

Fine sand

15.0

Saline

2.01

0.568

0.72

Clay (Cambrian)

35.5

Fresh

1.83

0.991

0.96

Clay (Kaolin)

35.5

Fresh

1.80

1.085

0.91

Clay (Cambrian)

35.5

Saline

1.83

0.991

0.96

Clay (Cambrian)

35.5

Saline

1.79

1.097

0.90

Table 2 Grain-size distribution of fine and silt sands Particle size (mm)

≥0.6

≥0.3

≥0.15

≥0.075

Silt sand, mass (g)

1,250

1,250

1,000

1,500

Fine, mass (g)

1,000

1,500

1,500

700

0.70 m, Fig. 4.

The Destruction of Stabilized Expansive Clays Due to Frost Action

55

Fig. 4 A layer of the clay-cement composite under the plastic film deteriorated due to frost

• Clay-cement composite was fully degraded in terms of granules and volume alongside the borderline layers of clay [6], in the form of irregular networks releasing aggregates of the clay-cement composite, Fig. 5.

Hkc73 cm

Fig. 5 Capillary action of the frozen clay-cement composite, H kc > 0.70 m

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K. M. Kordian and K. Lukasz

Fig. 6 Effects of frost-induced damage and swelling of the clay-cement 10 mm) layer (

The photographs below show the typical symptoms and effects of frost-induced deterioration of the clay-cement composite at the bottom of the excavation (Fig. 6).

3 Summary and Final Conclusions Based on an analysis of geotechnical investigation and identification testing of the clay-cement composite state, one shall confirm the harsh form of deterioration of the frozen zone of the cement-stabilized composite. Deterioration caused by the cyclic freezing of the surface zone of the subsoil at the bottom of the excavation took place due to incorrectly applied mechanical cement stabilization, despite an attempt to use other water and frost protection measures. Direct causes of frost action on expansive soils include incorrect selection of stabilization method, natural process of cyclic freezing and thawing, and the impact of precipitation and groundwater—piezometric level, which have led to enhancement of the negative role of freezing and swelling of clay, disaggregation, and quick soaking leading to changes in volume of clay in the cement-stabilized zone. As a result, the clay-cement composite going through cyclic freezing was transitioned in the stabilization zone into a liquid state, whereas the range of deterioration of the subsoil structure covered practically the entire area of stabilization performed in the excavation as a result of using unreasonable protection measures. The presented example of effects of frost-induced deterioration of expansive soils focuses our attention on cases of leaving ineffectively protected open excavations for a period of winter frosts, which still occur in geotechnical reality. As known, layers of clay of the Pozna´n series, e.g., [6], can be characterized by the unique properties and extreme sensitivity to weather changes, in particular frost, precipitation, and underground waters. The presented example allows to assume that the basic engineering knowledge related to freezing problems available to specialists, mentioned in the first part of

The Destruction of Stabilized Expansive Clays Due to Frost Action

57

the chapter, as well as experiences regarding usefulness of cement in stabilization of expansive soil, particularly highly dispersive clay of the Pozna´n series, was ignored or lost in confrontation with the arguments of substitute technology.

References 1. Kumor MK (2016) Expansive clays of building ground in Bydgoszcz. Some geotechnical problems [in Polish]. University of Technology and Life Sciences, Bydgoszcz, p 235 2. Jershov ED (1983) Formirovanie kriogennyh tekstur pri epigeneticzieskom i syngeneticzeskom promierzani dispiersnych porod. Problems of geocryology. Publishing House Nauka Moscow, pp 143–152 3. Kozłowski T (2011) Low temperature exothermic effect on cooling of homoionic clays. Cold Reg Sci Technol 68:139–149 4. Kumor MK (2015) The destruction of stabilized expansive clays due to frost action [in Polish]. In˙zynieria Morska i Geotechnika [Polish periodical] 3:517–220 5. Niedzielski A, Kumor MK (2009) Geotechnical problems of foundation on expansive soils in Poland. In: 15th national conference of soil mechanics and geotechnical engineering, Bydgoszcz 6. Olchawa A, Kumor MK (2008) The effect of cyclic freezing on frost-induced swelling and contraction of composite soil materials: organic soil—fly ash, organic soil—monomineral clay, [in Polish]. “Hydrotechnika” Archive Z.2 T. XXXII S. pp 299–307

Experimental Study on Shear Strength Characteristics of Silty Sand Under Freezing and Thawing Conditions Yali Li and Yahu Tian

Abstract This paper combines the construction process and geological conditions of the artificial freezing method on the contact channel of Zhengzhou Metro Line 3, according to the remolded silty soil with the moisture content of 19.5% at room temperature and negative temperature (−1, −5 and −10 °C) to conduct a largescale direct shear test. This study analyzed the variation of shear properties of silty sand with temperature. Test results show that the shear stress–shear displacement curve of silty soil in the melted state is of the strain hardening type, while under freezing conditions it shows to be a strain softening type. As the cooling temperature decreases, the peak strength and cohesion of the silty soil increase significantly, but the internal friction angle increases relatively small. When the silty soil is in the melted state and frozen at −1 °C, the shearing phenomenon occurs in the initial stage of the test, while only the dilatancy occurs when freezing at −5 and −10 °C; the maximum amount of dilatancy is negatively correlated with vertical pressure and positively correlated with cooling temperature. Keywords Frozen silty sand · Shear strength · Shear dilatancy

1 Introduction Zhengzhou Metro Line 3 is mainly located in the sandy soft soil layer of the alluvial plain of the Yellow River, and the groundwater level is about 15–20 m deep. According to the design document of Line 3, the line sections from Erqi Square Station to Shuncheng Street Station basically pass through the saturated sand layer, so the communication channels between the sections are constructed by artificial freezing method. In the construction process of artificial freezing method, the bearing capacity and stability of the frozen wall has always been one of the problems in the project. In recent years, researchers have carried out a series of researches in combination with specific actual engineering conditions and have obtained a lot of research results. Wu Y. Li (B) · Y. Tian Beijing Jiaotong University, Beijing 100044, China e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_7

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et al. [1] proved that the increase of confining pressure or the increase of temperature significantly enhanced the plasticity and strain hardening behavior of frozen sand by triaxial shear test. Li et al. [2] obtained a direct shear test, and the shear displacement when the frozen soil was destroyed was generally less than 2.5 mm. Shen [3] obtained the variation of the shear strength index of unsaturated soil under different suction, moisture, and dry density conditions by direct shear test. De Guzman [4] obtained large shear strength of compacted roadbed fillers during freezing through indoor large direct shear test, but its shear strength after freezing and thawing and melting conditions. Reduced by more than 50%, Niu et al. [5] found that the initial tangential modulus of frozen Lanzhou loess increased linearly with the increase of confining pressure by triaxial test of frozen lanca loess at −6 °C in the range of 1–15 MPa. When the confining pressure is greater than 11 MPa, it increases linearly with the increase in confining pressure. Lian [6] used a direct shear test machine and found that the cohesive force and internal friction angle of the frozen clay increased significantly with the decrease in temperature. But when the temperature is lower than 6 °C, the low-temperature effects on the direct shear strength are smaller and smaller. Czurda and Hohmann [7] demonstrated through the indoor direct shear test that the shear strength of frozen clay changes with time and temperature mainly due to the change of ice cohesive force, and the frictional resistance is basically constant. Feng et al. [8] found that undisturbed moraine soil has certain structural strength through large-scale direct shear test, and the strength of remolded moraine soil will decrease with the increase in water content. At present, many achievements have been made in the study of the mechanical properties of frozen soil. However, because the physical and mechanical properties of frozen soil are closely related to a given location’s own unique soil conditions, it is difficult to apply the theoretical or experimental research results obtained by a particular soil to predict directly other types frozen soil properties. In the construction of the subway contact channel freezing method, the soil properties, water content, and overburden load have significant effects on the mechanical properties of the frozen soil and the stability of the frozen wall. Therefore, this paper combines the geological conditions of Zhengzhou Metro Line 3 and analyzes the variation of the strength and dilatancy of silty sand under different cooling conditions through largescale direct shear test, in order to provide certain support for the on-site construction of Zhengzhou Metro Line 3 guide.

2 Test Content and Method 2.1 Soil Sample The soil samples taken from the Erqi Square Station to the Shuncheng Street Station section were tested, and the basic physical parameters of the soil were obtained as shown in Table 1. Due to the high groundwater level in the stratum of the subway line

Experimental Study on Shear Strength Characteristics … Table 1 Basic parameters of the soil

Property

61 Values

Specific gravity

2.69

Natural moisture content (%)

25.2

Precipitation moisture content (%)

13.8

Liquid limit (W L , %)

28.6

Plastic limit (W P , %) Maximum dry density

17.4 (g/cm3 )

1.73

from Erqi Square Station to Shuncheng Street Station, the site construction adopts the excavation mode of first precipitation and then construction. According to the test after excavation of the foundation pit of Erqi Square Station, the natural moisture content of silty sand is 25.2%, and the water content after precipitation is 13.8%, indicating that the effect of on-site precipitation measures on soil water content is significant. The main line of Shuncheng Street Station to Erqi Square Station on Line 3 is constructed by shield method. Considering that the precipitation effect of the communication channel between the lines may not be as obvious as the station, the water moisture of the soil sample in this test is intermediate value (19.5%) between the saturated water moisture 25.2% and the water moisture after precipitation 13.8%. The particle gradation curve is shown in Fig. 1. The fine particle content is 47.96%, and the main fine particle component is silt. According to the specification [9], it is named as silty sand. Fig. 1 Particle size distribution of the silty sand examined

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2.2 Test Equipment and Method The direct shear instrument used in the test is shown in Fig. 2, in which the shear box has a square cross section and its geometric dimension is length × width × height (300 mm × 300 mm × 200 mm); the shear box is connected to the external cold bath. The freezing of soil samples is achieved. The maximum vertical and horizontal loads that can be applied by the direct shear are 100 kN and 150 kN, respectively; the lower box of the shear box does not move during the test, and the upper box completes the shearing process of the soil sample at a speed of 1 mm/min under the action of horizontal force. The compaction coefficient of the soil sample in the test is 0.93; five temperature sensors are arranged in the height direction of the shear box side to determine the temperature of the soil during the test; the soil sample is cooled and cooled, so that the sensor temperature reaches the predetermined temperature target value. After the soil sample temperature was stable for 2 h, the horizontal load and the vertical load were applied to perform the shear test. In the test, the temperature of the soil sample was room temperature and four temperature conditions of −1, −5, and −10 °C, and the vertical pressure was 50, 100, 200, and 300 kPa under each temperature condition. According to the test results, the shear characteristics of frozen soil under different soil conditions were compared and analyzed.

Fig. 2 Direct shear apparatus

Experimental Study on Shear Strength Characteristics …

63

3 Analysis of Test Results 3.1 Shear Stress–Shear Displacement Curve Characteristics Figure 3 shows the shear stress–shear displacement curves for different temperatures and vertical pressure conditions. It can be seen from Fig. 3a that the stress–displacement curve of the silt soil is strain hardened at room temperature. There are no obvious peak points. In the initial stage of shear displacement of 0–4 mm, the shear stress increases proportionally with the shear displacement, and the growth rate is larger. This is mainly due to the joint and embedding of soil particles under the combined action of shear stress and vertical pressure, which increases the compactness and mechanical bite force of silty sand. When the shear displacement gradually increases to 4 mm, the shear stress growth rate becomes smaller and smaller, which is characterized by strain hardening. The shear deformation at this stage is mainly due to the mutual friction between the soil particles and the shearing displacement of the soil particles. In the frozen state, the development trend of shear stress of silty sand with shear displacement is shown in Fig. 3b–d. The shear stress has obvious peak points, which

(a) Room temperature

(c) T= -5

(b) T= -1

(d) T= -10

Fig. 3 Relationship curves between shear stress and shear displacement

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is softening. It can be seen from Fig. 3b that when the shear displacement is less than 1 mm, the shear stress increases sharply with the increase in the displacement. At this stage, the relationship between the two curves is approximately straight; this phenomenon is more significant with the decrease in the cooling temperature. When the shear displacement is between 1 and 2 mm, the shear strength of silty sand decreases with the increase in displacement. This is due to the plastic deformation of the silty soil, the soil begins to yield but the plastic strain increases the powder. The frozen strength of silty sand is continuously enhanced, and this strength prevents the soil structure from continuing to deform. When the shear displacement exceeds 2– 4 mm, the shear stress in the soil sample suddenly decreases or gradually decreases, and the shear deformation continues to increase. At this time, the fracture surface is basically formed in the soil sample. Shear strength is mainly derived from the friction of the shear plane.

3.2 Shear Strength Characteristics Figure 4 shows the trend of peak strength change of silty sand under different temperature conditions; in order to make the abscissa more intuitively describe the relationship between silty soil temperature and shear strength, the fracture strength of soil samples at room temperature regarded as 0 °C is the same. According to the literature [10], for the stress–strain relationship curve of the strain hardening type, the fracture strength of the soil sample generally takes the corresponding value when the shear strain is 2%, and for the strain softening curve, the shear stress value of the peak point is taken. Fig. 4 Relationship between failure strength and temperature

Experimental Study on Shear Strength Characteristics …

65

It can be seen from Fig. 4 that the failure strength of silty sand increases with the increase in the vertical pressure and increases remarkably as the cooling temperature decreases. When the vertical pressure is increased from 100 to 300 kPa, the breaking strength increases by about 30%. This is because the structure of the soil resists deformation under the action of large vertical pressure, which causes the vertical pressure to affect the strength and deformation characteristics of the silt. When changing from room temperature to a cooling temperature of −1 °C, the breaking strength of silty sand increased by about 5 times; when the cooling temperature was changed from −1 to −5 °C, the breaking strength increased by about 2.5 times. This is because under the condition of negative temperature, the pore water exists in the form of pore ice. The high-strength ice filling bears a certain shearing force in the pores of the soil particles, and the cementing force between the soil skeleton particles and the ice particles has certain binding force [11]. When the cooling temperature is lower, the larger the ice content, the greater the composition and structural changes inside the soil, resulting in stronger attraction and bonding ability between the particles. According to the Mohr–Coulomb strength theory, the relationship between the peak strength of silty sand at different temperatures and the vertical pressure is shown in Fig. 5a. The relationship between the cohesive force and the internal friction angle of the silty sand at different temperatures and the temperature can be obtained by fitting the intercept and slope of the straight line in Fig. 5b. It shows that the cohesion and internal friction angles increase sharply as the temperature is lowered from room temperature to −1 °C. When the cooling temperature was lowered from −1 to −5 °C, the cohesive force increased from 285 to 546 kPa; when the cooling temperature was lowered from −5 to −10 °C, the cohesive force increased from 546 to 990 kPa, almost linearly increasing. As the cooling temperature continues to decrease, the internal friction angle increases only by 6°–8°. For the silty soil in the frozen state, the bonding force of the ice plays a decisive role, which on the

Fig. 5 a Failure stress-vertical pressure fitting straight line; b relationship between cohesion, internal friction angle, and temperature

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one hand increases the strength of the soil and on the other hand strengthens the surface cementing force with the soil particles. The lower the cooling temperature, the higher the ice content, the larger the contact area between the soil particles and the ice, and the stronger the cementing ability, so the soil cohesive force is also larger [12]. Under freezing conditions, the friction between the pore ice and the soil particles is increased, and the bite force between the soil particles is increased, which leads to a large increase in the internal friction angle. However, in the case where the soil water content is constant, the cooling temperature is further lowered. The amount tends to be closer to the value, and the embedding between the ice particles and the soil particles is gradually stabilized, so that the internal friction angle of the soil is no longer greatly increased.

3.3 Shear Dilatancy The curve of the dilatancy–shear displacement of the silt soil in the direct shear test is shown in Fig. 6. The amount of dilatancy of the ordinate is the difference between

(a) Room temperature

(c) T= -5 Fig. 6 Dilatancy–shear displacement curve

(b) T= -1

(d) T= -10

Experimental Study on Shear Strength Characteristics …

67

the vertical displacement value of each point and the initial vertical displacement value. Figure 6a shows that at room temperature, the silt soil in the initial stage of the shear test showed a phenomenon of first dilating and then dilating. At a temperature of −1 °C, as shown in Fig. 6b, when the vertical pressure is greater than 100 kPa, the silt soil exhibits a shearing phenomenon; when the vertical pressure is less than 100 kPa, the silty sand exhibits only dilatancy. When the cooling temperature is −5 and −10 °C, as shown in Fig. 6c and d, the silty soil only undergoes dilatancy, and the dilatancy tendency is obvious. At room temperature and the initial shear stage of −1 °C, the structure of the silt soil changed, and the soil particles squeezed into the pores of the soil, resulting in a smaller volume. When the cooling temperature is −5 and −10 °C, the presence of a large amount of pore ice in the soil makes the soil have lower compressibility. When a certain shear displacement is reached, the soil has become more compact. Under the continuation of the shearing force, the soil particles and ice particles will inevitably move or roll on the shear plane or the shear band, resulting in dilatancy behavior [13]. Table 2 shows the maximum dilatancy of the silt soil at a shearing displacement of 12 mm at different freezing temperatures. When the test temperature is the same, the maximum dilatancy of silty sand has a negative correlation with the vertical pressure. That is, as the vertical pressure increases, the overall dilatancy shows a decreasing trend, such as when the freezing temperature is −5 °C. With the increasing vertical pressure, the amount of dilatancy of silty sand is 8.39, 6.33, 5.74, and 5.02 mm. This is because the greater the vertical pressure, the greater the friction between the particles, the less likely the relative misalignment between the particles, so the dilatancy is not easy to occur; conversely, the smaller the friction generated, the more likely the dilatancy occurs [14]. Under the same conditions of vertical pressure, the dilatancy of silty sand is greatly affected by the freezing temperature. The lower the freezing temperature, the larger the dilatancy. For example, when the vertical pressure is 200 kPa, from room temperature to negative temperature silt. The maximum amount of dilatation will increase by about 1–2 mm. The lower the cooling temperature, the more ice content in the frozen soil. During the shearing process, the more the displacement and slip movement of a large number of ice particles and soil particles, the greater the volume change in the shear direction, so the more the amount of dilatancy. Table 2 Amount of shear dilatancy at different freezing temperatures Temperature (°C)

Vertical pressure (kPa) 100

200

300

20

50 2.94

2.56

2.28

2.02

−1

6.37

5.65

4.05

2.93

−5

8.39

6.33

5.74

5.02

−10

12.53

9.87

7.66

6.92

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4 Conclusion Through the direct shear test of silty sand at room temperature and different freezing temperatures, the shear characteristics of the silt soil of Zhengzhou Metro Line 3 were compared and analyzed. The main conclusions are as follows: 1. For silty soil under room temperature, the stress–displacement curve is strain hardening in the vertical pressure range of this experiment, and the shear stress remains stable when the shear displacement reaches 6 mm; within 1–2 mm in the initial stage of shearing shrinkage occurred, and the shear dilatation began to show significant dilatancy after reaching 2 mm. 2. For frozen silt, the stress–displacement curve appears as a strain softening type. In the frozen state, the shear strength of the silt is multiplied by the room temperature silt, and the change of the cooling temperature is negatively correlated with the shear strength. When the cooling temperature is −1 °C, when the vertical pressure is greater than 100 kPa, the silt soil will shrink. When the vertical pressure is less than 100 kPa, the silt soil only shows dilatancy; the cooling temperature is −5 and −10 °C, and only the dilatancy of the silty soil occurred in the test vertical pressure range. The maximum dilatancy of frozen silty sand is negatively correlated with vertical pressure and positively correlated with cooling temperature. 3. The cohesive force and internal friction angle of silty sand under melting conditions are 30 kPa and 25°, respectively, and the corresponding values when the freezing temperatures of silty sand are −1, −5 and −10 °C, respectively. They are 285 kPa and 49°, 546 kPa and 55°, 990 kPa and 61°, respectively. Under the freezing condition, the cohesion and internal friction angle of the silt soil increased significantly compared with the melting state, but the internal friction angle increased less as the freezing temperature decreased.

References 1. Wu Z et al (1994) Strength characteristics of frozen sandy soil. J Glaciol Geocryol 16(1):15–20 2. Li D (2004) Study on shear strength characteristics of frozen soil and its experimental. J Anhui Univ Sci Technol 24(5):52–55 3. Shen C et al (2009) Effects of suction, moisture content and dry density on shear strength of remolded unsaturated soil. Rock Soil Mech 30(5):1347–1351 4. De Guzman EMB (2018) Large-scale direct shear testing of compacted frozen soil under freezing and thawing conditions. Cold Reg Technol 151:138–147 5. Niu Y et al (2016) Experimental study on deformation and strength characteristics of frozen Lanzhou loess. J Lanzhou Jiaotong Univ 35(1):112–115 6. Lian M (2018) Study on shear strength characteristics of artificially frozen clay. Sichuan Build Mater 44(10):90–93 7. Czurda KA, Hohmann M (1997) Freezing effect on shear strength of clayey soils_1000035493224410. Appl Clay Sci 12(1):165–187 8. Feng J et al (2008) Experimental study on large direct shear strength characteristics of hail soil in a railway in Yunnan. Rock Soil Mech 29(12):3205–3210

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9. GB/T50145–2007 (2008) Standard for engineering classification of soil. China Planning Press, Beijing 10. Wang Q et al (2016) Large direct shear test study on coarse-grained packing of high-speed railway subgrade in cold area. J Railw 38(8):102–110 11. Wang P et al (2014) Study on mechanical properties of crushed stone aggregate under direct shear. J Railw 36(2):103–108 12. An W, Wu Z (1989) Temperature and moisture stress of frozen soil and its interaction. Lanzhou Jiaotong University Press, Lanzhou, pp 178–179 13. Lu P, Liu J (2015) Direct shear test study on the interface between frozen soil and concrete. J China Railw Soc 37(2):106–110 14. Xu C et al (2018) Dilatancy and shear characteristics of sand and its influence on shear strength. J Arch Civil Eng 35(4):27–33

Measurement for Permeability of Frozen Soil by Transient Pulse Method Tetsuya Tokoro and Tatsuya Ishikawa

Abstract In this study, permeability coefficient of frozen soil has been measured by transient pulse method for specimens in which ice lenses did not exist by applying axis stress more than ice pressure calculated by generalized Clausius–Clapeyron equation. The applicability of the transient pulse method for frozen soil was examined by comparing the previous study conducted by authors. It is found that the permeability coefficient has a dependency on temperature and changes drastically over the tested temperature range. These tendencies of the permeability coefficient under negative temperature were similar to the permeability coefficient obtained by the constant head permeability test. Therefore, it is concluded that transient pulse method can be available to measure the permeability coefficient of frozen soil. Keywords Frozen soil · Permeability coefficient · Transient pulse method

1 Introduction Frost heaving does severe damage to infrastructures such as road and railways in cold regions. Several studies have been made on frost heaving for a long time, and based on the prominent research findings, the mechanism of frost heaving is progressively getting understood. However, the detailed mechanism of water flow in frozen soil still remains unclear. It is indispensable for solving the frost heaving mechanism to estimate water flow in frozen fringe. Some permeability measurement methods have been proposed already. Burt and Williams [1] measured the permeability coefficient of frozen soil by using the solution of lactose in water as seepage water. Although using a water solution enables the permeability test to be conducted, it dissolves pore ice in frozen soil and, accordingly, causes overestimation of permeability since T. Tokoro (B) National Institute of Technology, Tomakomai College, Tomakomai, Japan e-mail: [email protected] T. Ishikawa Hokkaido University, Sapporo, Japan e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_8

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the freezing point is depressed. Horiguchi and Miller [2] proposed the “sandwich method,” which measures water movement due to regelation. Regelation is a phenomenon whereby ice melts under high pressure and grows at lower pressure. This method cannot estimate genuine permeability for frozen soil. Black and Miller [3] developed a method that independently applies water pressure and confined stress. However, this method allows ice nucleation to occur in the specimen and uses glycol solution as seepage water. As mentioned above, it is difficult to measure the permeability coefficient of frozen soil since ice lenses obstruct water flow in the soil and water in the plumbing path is frozen without a device. These problems must be resolved to estimate water flow in frozen soil. Tokoro et al. [4] proposed a method that addressed the abovementioned problems. This method prevents ice lenses from forming in frozen soil by applying axial stress greater than the ice pressure that occurs in forming ice lenses. Moreover, freezing only the specimen center, while maintaining a positive temperature at the edges, enables the use of pure water instead of a water solution. However, there was a problem that the temperature of the specimen is not uniform. In addition, recently there are some attempts to obtain the permeability coefficient of saturated and unsaturated frozen soils [5, 6]. Furthermore, some models to predict the permeability coefficient of frozen soil have been proposed [7, 8]. Nevertheless, the estimation of permeability for frozen soils has not yet to be established. The purpose of this study is to examine the application of transient pulse method [9] to frozen soil in order to solve those problems. Transient pulse method has been widely used for estimation of low-permeable rocks since 1970s [10, 11]. The test results were assessed by comparing the test result obtained by previously proposed method [4]. This paper reports the results of the permeability tests for a frost susceptible soil and compares the permeability coefficient with previous study.

2 Methodology 2.1 Material The material used in this study is Fujinomori clay. Table 1 and Fig. 1 show the physical properties and grain size distribution of Fujinomori clay, respectively. Fujinomori clay is known as a frost susceptible soil, which means it contains unfrozen water content below 0 °C. The unfrozen water content of Fujinomori clay, measured by pulse NMR, is shown in Fig. 2. Fujinomori clay has sufficient unfrozen water, especially at near 0 °C. Table 1 Physical properties Sample name

ρ s (g/cm3 )

W L (%)

W P (%)

IP

Fujinomori

2.69

40.5

24.7

15.8

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100

Fig. 1 Grain size distribution

Passing finer (%)

80

60

40

20 0 0.001

0.01

0.1

1

Grain size (mm)

35

Fig. 2 Unfrozen water content Unfrozen water content (%)

30 25 20 15 10 5 0 -20

-15

-10

-5

0

o

Temperature ( C)

2.2 Apparatus Figure 3 shows the permeability test apparatus for the transient pulse method. The apparatus consists of a cell, stainless steel tanks, and low-temperature circulator. The apparatus was placed in an incubator whose temperature can be controlled. The cell is a hollow structure in which antifreeze liquid can be circulated in order to control the temperature of the specimen. Inside of the cell is made of stainless steel of which thermal conductivity is high. Furthermore, the diameter of specimen is 20 mm so that the temperature can keep unique through the specimen by circulating antifreeze liquid. A thermistor inserted in the cell measures the temperature of the cell. The pulse pressure is controlled by a regulator, connected to a compressor. Upstream tank was used to apply pulse pressure, and downstream tank was used

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T. Tokoro and T. Ishikawa Bellofram cylinder Connected to compressor

Stainless steel tank (Upstream) Pressure transducer Thermistor

Valve Pressure transducer Regulator

Stainless steel tank (Downstream)

Low temperature circulator

Fig. 3 Test apparatus

to confirm response of the pulse pressure. During the permeability test, pressure transducers measure the water pressure of upstream and downstream tanks. A Bellofram cylinder applies axial stress to the specimen σ 1 in order to prevent ice lenses from forming in the specimen. When the permeability test is conducted, pore water pressure Pw is applied. Therefore, the effective axial stress σ e (= σ 1 − Pw ) needs to be larger than pore ice pressure Pi to prevent frost heave from occurring. Pore ice pressure can be calculated using the following generalized Clausius–Clapeylon equation (GCCE) [12]. Pw vw − Pi vi =

Lw θ T0

(1)

where vw and vi are the specific volume of water and that of ice, respectively, L w is latent heat, and T 0 is 273 K.

2.3 Measurement Procedure The samples were reconstituted from slurry with 80% water content under preconsolidation pressure of 1 MPa. After the consolidation, the specimen was frozen by circulating the antifreeze liquid. The temperature of the low-temperature circulator was set to −10 °C, and the cooled antifreeze liquid was circulated as the thermal shock for preventing the pore water from being in a supercooled state. Subsequently, the temperature was set to −0.45 °C, which is lowest temperature among subzero temperature to perform the permeability test. The temperature of the incubator was also the same temperature as the specimen. Axial stress of 1 MPa was applied to the specimen during freezing in order to prevent ice lenses from forming in the specimen. In this study, the specimens were frozen laterally. The specimens were frozen; the

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Pressure (kPa)

Fig. 4 Conceptual diagram of transient pulse method

P1 P

Pf P2 Time (s)

method prevents ice lenses from forming in the specimen so that freezing direction is thought to have an insignificant effect on the permeability coefficient. In this study, solution of sodium chloride was adopted as test water since the permeability test was conducted below 0 °C. The test water was replaced by the solution stored at the same temperature as the specimen in prior to the start of the tests for frozen condition. Figure 4 shows the conceptual diagram of transient pulse method. The initial pressures in the upstream and downstream were atmospheric pressure. The pulse pressure P of 100 kPa was selected. The downstream tank was closed, and the pulse pressure was applied to the upstream tank. The permeability tests were conducted until the water pressure of upstream and downstream reached to Pf . The pressure decay depends on the permeability of specimens, the volume of the upstream and downstream tanks, and some water properties. The simple solution was derived by Brace et al. [9], and the permeability coefficient can be obtained as follows. P1 − Pf =

P V2 −αt e V1 + V2

(2)

in which α=

K A V1 + V2 μβ L V1 V2

(3)

where K is the permeability; P1 is the pressure in the upstream tank at time t; Pf is the final water pressure; P is the pulse pressure; V 1 and V 2 are the volumes of the upstream tank and downstream tank, respectively; A is the cross section of the specimen; L is the length of the specimen; μ is the viscosity coefficient of water; and β is the compressibility of water. The permeability can be calculated by Eq. (4). K =

μβ L V 1 V2 α A(V1 + V2 )

(4)

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α can be obtained by fitting the relation between pressure decay and time with Eq. (2). The permeability K is mainly used for rocks, and it is a liquid-independent index of the permeability. The permeability coefficient can be calculated with consideration for gravity and the viscosity coefficient of water. k=K

ρg μ

(5)

These procedures were repeated for different temperatures, and permeability coefficients on the rising temperature process were obtained. For unfrozen condition, a separate test was conducted at the temperature of 0.2 °C.

3 Results Figure 5 shows one example of the pressure decay curve of upstream and downstream at the temperature of −0.45 °C. The pressures in both upstream and downstream decrease and increase, respectively, and get to be closed with increasing time. Thus, the pressure is certainly transmitted through the specimen. Figure 6 shows the permeability coefficient obtained by the transient pulse method. The permeability coefficient obtained by constant head permeability test for the same sample [4] was plotted in the figure. Compared with the permeability coefficients by different method, the permeability coefficient in this study has same temperature dependency as the previous study. When compared with the unfrozen condition, the permeability coefficient drops by up to approximately one order. Furthermore, the permeability coefficient decreases with the decrease in the temperature. Tokoro et al. [4] indicated that the temperature dependency of the permeability coefficient is attributed to the unfrozen water content, which has strong temperature dependency. The permeability coefficient of this study shows the similar temperature dependency Fig. 5 Pressure decay curve

100

-0.45oC Upstream Downstream

Pressure(kPa)

80

60

40

20

0

0

20000

40000

60000

Time (s)

80000

100000

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Permeability coefficient(m/s)

Fig. 6 Permeability coefficient

10

-8

10

-9

10

-10

10

-11

10

-12

-0.6

77

Fujinomori clay Transient pulse method Constant head permeability test (Tokoro et al. 2016) -0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

o

Temperature ( C)

to previous study. Therefore, even though there are some considerations such as the effect of the solution on the permeability coefficient, transient pulse method can be applicable to frozen soils.

4 Conclusion The permeability tests for the frozen soil by using transient pulse method were conducted. The permeability coefficient obtained by the transient pulse method has same temperature dependency as the permeability coefficient obtained by the constant head permeability test. Thus, there is a high possibility that the transient pulse method can measure the permeability coefficient of frozen soils.

References 1. Burt TP, Williams PJ (1976) Hydraulic conductivity in frozen soils. Earth Surf Process 1:349– 360 2. Horiguchi K, Miller RD (1980) Experimental studies with frozen soil in an “ice sandwich” permeameter. Cold Reg Sci Technol 3:177–183 3. Black PB, Miller RD (1990) Hydraulic conductivity and unfrozen water content of air-free frozen silt. W Resour Res 26:323–329 4. Tokoro T, Ishikawa T, Akagawa S (2016) Temperature dependency of permeability coefficient of frozen soil. In: Proceedings of GEOVancouver 2016, Vancouver, [1/1(USB)3896] 5. Watanabe K, Osada Y (2017) Simultaneous measurement of unfrozen water content and hydraulic conductivity of partially frozen soil near 0 °C. Cold Reg Sci Technol 142:79–84 6. Watanabe K, Osada Y (2016) Comparison of hydraulic conductivity in frozen saturated and unfrozen unsaturated soils. Vadose Zone J 15

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7. Azmatcha TF, Sego DC, Arensonb LU, Biggarc KW (2012) Using soil freezing characteristic curve to estimate the hydraulic conductivity function of partially frozen soils. Cold Reg Sci Technol 83–84, 103–109 8. Lebeau M, Konrad J-M (2012) An extension of the capillary and thin film flow model for predicting the hydraulic conductivity of air-free frozen porous media. W Resour Res 48 9. Brace WF, Walsh JB, Frangos WT (1968) Permeability of granite under high pressure. J Geophys Res 73:2225–2236 10. Zoback MD, Byerlee JD (1975) The effect of microcrack dilatancy on the permeability of westerly granite. J Geophys Res 80:752–755 11. Yang S, Zhou HW, Zhang SQ, Rena WG (2019) A fractional derivative perspective on transient pulse test for determining the permeability of rocks. Int J Rock Mech Min Sci 113:92–98 12. Edlefsen NE, Anderson ABC (1943) Thermodynamics of soil moisture. Hilgardia 12–2:117– 123 (Univ California, Berkley)

Effects of Permafrost on Earthquake Resistance of Transport Facilities in the Baikal–Amur Mainline Area T. A. Belash

and A. M. Uzdin

Abstract The permafrost region includes about 50% of seismic areas of Russia. One of the largest Russian railway lines, the Baikal–Amur Mainline (BAM), runs through these areas. Currently, there is much concern about the continuation of its construction in an effective manner and development of the adjacent areas that are rich in mineral resources and woods. Key characteristic factors of this region include permafrost occurring down to a depth of several hundred meters, long severe winter period, strong winds, seismic rating of up to 9 and higher. Earthquake consequences have never been considered as a natural disaster because the territory is sparsely populated. However, with anticipated populating and further development of this area in the nearest future, studying of seismic manifestation, as well as implementation of efficient solutions ensuring reliability of transport buildings and structures, will be an important national task. By reviewing geotechnical and seismic conditions in the mainline area, one of the most hazardous parts of the route can be defined, i.e., the western part where permafrost penetration is as deep as 200 m and deeper, with permafrost soil temperatures down to minus 6 °C with high ice content in the soil. This part of the mainline is characterized by rate 5–10 earthquake manifestations. In addition, mudflows, snow slips, and landslides are common in this part of the mainline. Seismic activity in this region is characterized not only by high degree of earthquake intensity, but also by frequency of earthquake manifestations. According to seismological information of researchers, in the mainline area rate 8 earthquakes can be expected to repeat in 15–20 years, rate 9 earthquakes can be expected to repeat in 60–70 years, and rate 10 earthquakes can be expected to repeat in 200–250 years. This repetition rate of earthquakes gives significant rise to the medium frequency of earthquakes in one geographic point of a seismic area, which is a parameter taken into account by seismic construction regulations. This paper discusses the issues of permafrost effects on the seismic hazard of the mainline area and includes T. A. Belash (B) · A. M. Uzdin Emperor Alexander I St. Petersburg State Transport University, St. Petersburg 190031, Russia e-mail: [email protected] A. M. Uzdin e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_9

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recommendations for the need to consider these effects when designing facilities of transport infrastructure. Keywords Permafrost · Seismic hazard · BAM area · Seismic protection

1 Introduction As known, the Baikal–Amur Mainline (BAM) route starts at Lena railway station and ends in the city of Komsomolsk-on-Amur. It runs through the areas of Irkutsk region, Buryatia, Amur and Chita regions, Khabarovsk Territory, and South Yakutia. It is of major importance for economical development of Russia, because these are areas rich in woods, furs, various mineral resources, energy resources, and other natural resources. The key feature of this mainline is that it runs through poorly studied taiga areas. Key characteristic factors of this region include permafrost occurring down to a depth of several hundred meters, strong winds, low ambient temperatures, severe winter periods, and high seismic rating of up to 9 and higher. Earthquake consequences have never been considered as a natural disaster because the BAM area is sparsely populated. However, in the nearest future active, reclamation, development, and populating are expected in these areas. The beginning of growth and changes in this direction can be seen already. To this end, the implementation of rational and advanced technologies is an important national issue that ensures reliable and safe functioning of transport infrastructure facilities taking into account the demanding conditions of construction. The area of the mainline is characterized by the presence of permafrost soils with various modes of occurrence. Permafrost soils in western and eastern parts of the mainline occur mainly as spots, while in the central part there is a continuous permafrost along the length of 2,500 km. Permafrost soils in western and eastern parts of the mainline are classified as high-temperature soils (above minus 2 °C), and permafrost soils in the central part are low-temperature soils (under minus 2 °C) in terms of their temperature mode. Maximum seasonal freeze depth of the soil is 3.5 m. The most intensive seismic activity is observed in the Sayan–Baikal region. In this region, earthquakes occur with a quite high repetition rate and intensity. Earthquake manifestations in conditions of permafrost are investigated in many research works and described in publications by Solonenko, Grib, Fedorov, and others [1–6]. Zonation of the mainline area by permafrost expansion and seismic activity is shown in Fig. 1. According to the analysis of severe earthquake consequences, earthquakes in permafrost areas are quite frequent and associated with high disturbing forces. For example, according to Solonenko [5], 11 strong (up to rate 10) earthquakes and about 1,500 earthquakes with a rate of up to 6 were recorded within the period of 1957– 1963 in the area of the present southwest of Yakutia. The following most significant earthquakes are mentioned in [6]: Tas-Yuryakh earthquake of 1967 (M = 7), South Yakutia earthquake of 1989 (M = 6.6), and many others. All earthquakes occurring

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(a) Okhotsk

Viluysk

Yakutsk

Tura Olekminsk Aldan

Mukhtuya Vitim

Kezhma

Bodaibo

Kirensk

Skovorodino

Bratsk

Komsomolsk-onAmur

Taishet Sretensk

Khabarovsk

Chita Irkutsk

Ulan-Ude

PetrovskZabaikalsky Vladivostok

Southern margin of permafrost expansion

Ditto, with a thickness from 200 to 300 m

Soil temperature isoline at a depth of 10 m

Ditto, with a thickness from 300 to 400 m

Zone of separate permafrost spots with a maximum thickness of up to 25 m

Ditto, with a thickness from 400 to 500 m

Zone of permafrost soil expansion with a maximum thickness of up to 100 m

Ditto, with a thickness greater than 500 m

Ditto, with a predominate thickness from 100 to 200 m

Areas of permafrost expansion with a thickness greater than 500 m

(b)

Kropotkin

Kansk Taishet

Ust-Kut

Bratsk

Bodaibo

Nymnyrsky

Oron Chara

Taluma

Nizhneudinsk

Nagorny

Tulun

Nizhneangarsk

Zhigalovo

Tyndinsky Toora-Khem

Zima Cheremkhovo

Kachug

Sosnovka

Amazar Tungokochen

Angarsk Irkutsk Slyudyanka Bayangol

Itaka

Ust-Zaza Khorinsk Ulan-Ude

Chita

Gorodok Akma Mangut

Rate 8 earthquakes Rate 9 earthquakes Rate 10 earthquakes

Fig. 1 Zonation of the BAM mainline area by permafrost expansion (a) and seismic activity (b)

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in these conditions are perceptible over huge areas. According to [1, 2], the North Baikal earthquake of April 29, 1917 (M = 6.5) was perceptible over an area of 500 thousand km2 , and the Muya earthquake of June 27, 1957, was perceptible over an area of about 2 mln km2 having a rate of 10–11. It is worth noting that similar conditions of construction are also observed in other countries, such as Canada, USA, and islands in the Arctic Ocean. On March 27, 1964, a large earthquake struck Alaska (M = 8.6) with a high disturbing force and tsunami. As a result of this earthquake, many civil buildings were destroyed, as well as 200 km of railways and 110 bridges. Strains were spread over an area of 300 thousand km2 (see Fig. 2) [7]. Another strong earthquake occurred in Alaska in October 2018 and resulted in damages to various transport infrastructure facilities (see Fig. 3) [8]. Despite the exacting nature of combined manifestation of permafrost and earthquake effects, there is a certain experience of construction, which is reflected in regulatory documents [9, 10]. In particular, it is pointed out in these documents that the construction site should be preferably located on areas with homogeneous soils and with flat, smooth topography. An advantageous factor is high continuity of soil in horizontal direction, the presence of rocky, low-compressible hard frozen and loosely frozen soils in the natural ground [4, 9]. Special requirements are imposed to keep the selected temperature mode of the ground during the entire service life of the structure in accordance with the selected principle of construction. In the areas of hard frozen soils, as well as in the earthquakeprone areas, the use of permafrost soils should be based on principle I, i.e., preservation of the frozen state of soil. When application of principle I is impossible, the use of principle II is allowed with foundations supported by rocky soils or other soils that are low-compressible upon defrosting, or by pre-defrosted and compacted soils, in accordance with Code of Practice SP 25.13330.2016: Foundation Engineering on Permafrost Soils, [11–13]. In this case, as noted in [3], principle I is the most rational solution for earthquake-prone areas that allows for reduction of the estimated seismicity rate. In contrast, the use of principle II in construction results in 1–2 points higher estimated seismicity rate. It is related to the fact that if, for example, a thaw crater is located under the building or structure, seismic waves are reflected from thaw crater walls resulting in resonance phenomena in this zone, which in turn result in differential settlements of the structure, soil loosening, and mud eruptions. According to recommendations related to construction in the areas of combined occurrence of permafrost and seismic effects, buildings and structures shall be of simple geometry in plan view and along their height. Extended buildings with height discontinuity shall be separated by antiseismic joints. Buildings should be designed as frameless structures with longitudinal and lateral walls, frame-type structures, and modular structures. When constructing on the basis of principle II, preferable option is frameless buildings with crosswise longitudinal and lateral walls that provide higher stiffness and reliability in conditions of potential strains. According to recommendations of [10], the most possible uniform distribution of mass and stiffness of the building must be provided along building length and width to avoid torsional oscillations. In addition, main load-bearing structures must

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Fig. 2 Earthquake consequences in Anchorage (Alaska, USA), March 27, 1964

be designed in accordance with the developed regulatory engineering documents: foundations, walls, columns, floors, and roofs of buildings and structures. The analysis of available solutions related to design, construction, and operation of transport facilities in the areas of permafrost combined with high seismic intensity shows that currently there are certain approaches formed to ensure strength and stability of these facilities. However, the exacting nature of the earthquake effects, which are characterized by multiple frequencies, repeatability, and unpredictability,

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Fig. 3 Earthquake consequences in Anchorage (Alaska, USA), 2018

dictates the need to search for the most promising and reliable methods and means of seismic protection, among which a specific place is held by special seismic protection systems in the form of seismic isolation and seismic damping. Seismic isolation is understood as a system for reducing the energy impact on a structure during seismic vibrations by installing members with increased elasticity at a certain level that make it possible to offset the response spectrum of the building away from the impact spectrum toward the long-period domain [14]. Effective application of these seismic protection means in permafrost areas is mentioned in publications of Eisenberg, Kharitonov, and others [15–17]. The special series 122 of residential buildings in Severobaikalsk was developed specifically for permafrost areas with the use of principle II. It makes use of adaptive seismic protection system, including elastic members and redundant members (see Fig. 4). Other design solutions for implementation of seismic isolation systems for permafrost areas are described in [18]. In particular, this publication includes examples of principle I implementation through erection of a pile foundation with elevated grill, which is considered as seismic isolation members (see Fig. 5) [18, 19].

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Concrete δ = 60 mm

Reinforced concrete lower crosswise strip

Sand mat

Fig. 4 Adaptive seismic protection system in series 122 large-panel building in Severobaikalsk: 1—upper crosswise strip; 2—lower crosswise strip; 3—supports of “flexible lower story”; 4— redundant members

Note that, also, there are other design solutions available for the components of seismic isolation for permafrost soil areas, for example, spring members, metal rods, frame studs, and other. Some of them are shown in Fig. 6 [20, 21]. The seismic insulation provides a considerable lowering of inertial loads on buildings and structures (by two times and more). However, it may be accompanied by significant relative displacements of seismically insulated parts of the building that can be as large as 0.5 m and more under low-frequency impacts. These displacements are the cause of destruction of the supporting members that perform the seismic insulation function, and ultimately result in the complete collapse of the building or structure. Numerous examples are known for collapse of building and structure with a “flexible” lower part in Skopje, Bucharest, Kobe, and other cities. To limit the relative displacement of seismically isolated parts of a structure, damper devices must be installed between them to perform the function of seismic damping. Taking into account the low ambient temperatures and severe climate, the most sensible solution of damping devices for permafrost areas is the use of elastic devices in the form of strain dampers and dry friction damper, with dry friction dampers being the preferable option. Some recommendations for selection of parameters of these dampers are presented in [14, 22]. Examples of dry friction damper implementation are shown in Fig. 5 illustrating a damper in the form of friction pair composed of a reinforced concrete slab on loose material base, and in Fig. 6 illustrating damping

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Fig. 5 Use of pile foundation with elevated grill for earthquake-prone areas of BAM: a pile foundation design: 1—tightening weight in the form of slab, 2—loose material, 3—casing, 4—piles, 5—elastic oscillation limiters; b 1—slab; 2—slab with recess; 3—piles; 4—solid block; 5—friction material; 6—spring stop; 7—recess in the slab; 8—friction layer; 9—pivoted joints; 10—recess in the solid block; c earthquake-proof foundation with the use of ice: 1—upper slab; 2—lower slab made of ice; 3—pile; 4—solid block; 5—soil; 6—thermal insulation; 7—pivoted joints

members composed of friction gaskets with high dry friction index. Authors of this paper were directly involved in designing the foundation structural solutions for the areas of combined permafrost and seismic activity shown in Figs. 5 and 6. Despite the quite large volume of research work carried out in the field of seismic isolation system application for earthquake-proof construction, the use of these modern design solutions for permafrost areas with severe climatic conditions is sporadic so far. There are no recommendations for their justification and calculation. So in this context, the need for further investigations arises aiming to study the peculiarities of behavior of the seismic protection system in question in the conditions of permafrost soils and to develop recommendations for design and calculation of these systems.

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Fig. 6 Antiseismic supports in building structure for permafrost areas: a elastic member designed as disk springs: 1—load-bearing structures of the building; 2—foundation; 3—supporting plates; 4—gasket; 5—elastic supporting members; 6—inner protrusions; 7—outer protrusions; 8—friction surfaces; 9, 10—friction gaskets; b elastic member designed as a pack of metal springs (longitudinal section and lateral section views): 1—upper part of the foundation; 2—lower part of the foundation; 3—recess in the upper foundation part; 4—recess in the lower foundation part; 5—elastic members in the form of springs; 6—removable friction member; 7—friction gaskets; 8—bolted joint

2 Research Technique As previously noted, the main structural component of seismic isolation system is the elastic member with high flexibility properties. These properties can be varied by changing materials of structural members and their cross sections and by selecting certain types of their joints with structural members of the building or structure. Currently, there are no any specific recommendations in regulatory engineering documents regarding selection and calculation of these members. Therefore, it was considered reasonable at the first stage to suggest a variant of calculation of seismic isolation elastic members using simplified calculation diagrams and approaches.

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Fig. 7 Overview of simplified calculation diagram

In order to develop the technique of elastic linkage member selection, an administrative large-panel building for transport purposes was considered. The building is supported by a base in accordance with principle I, i.e., preservation of frozen state of soil throughout the entire service life of the building. This principle is implemented by means of a pile foundation with elevated grill. The pile foundation is considered as a seismic isolation member. To assess flexible properties of this foundation, a method of selection of its characteristics was developed. Overview of the calculation diagram is shown in Fig. 7. This diagram ignores displacements occurring in the building itself. Building weight is replaced by a distributed load (q) and applied to an infinite stiffness rod, which is supported by weightless rods with a height of h that simulate piles. Upper ends of piles are connected to the infinite stiffness rod using pivoted joints, while their lower ends are rigidly fixed. Properties of soils were ignored at this stage. To simplify the calculation, the building was assumed to be only exposed to seismic load and gravity load due to building’s weight. Selecting the parameters of isolation includes two problems in this case. The first problem is classical for seismic isolation problems and consists in simultaneous ensuring strength and flexibility of supporting members. The second problem is the need to consider the effect of vertical tightening weight on the stiffness and strength of grill poles. Force diagram of pile is shown in Fig. 8. In this diagram, N is a vertical force defined by the portion of building weight corresponding to one pile; Q is a horizontal load corresponding to the seismic force; u is displacement of pile upper end in relation to its vertical position. Poles were assumed secured by pivoted joint. There were 240 poles under the building in question. Results of the calculation are presented in Table 1. Dimensions are identified in Fig. 9. Key working feature of the structural member in question is the presence of bending moment on the poles due to longitudinal load M = E J U  + NU

(1)

Therewith the shear force Q is defined by the following equation: Q = M  − NU  = −E I U  − NU 

(2)

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Fig. 8 Diagram of load distribution on pile assumed for the calculation

Table 1 Result of calculation

R—outer radius of pole, m

r—inner radius of pole, m

h—height of pole, m

0.100

0.0571

3.000

0.100

0.0346

3.100

0.110

0.0725

3.300

0.110

0.0638

3.400

0.110

0.0471

3.500

0.120

0.0901

3.500

0.120

0.0855

3.600

0.120

0.0797

3.700

0.120

0.0718

3.800

0.120

0.0588

3.900

0.130

0.1044

3.700

0.130

0.1012

3.800

0.130

0.0975

3.900

0.130

0.0930

4.000

0.140

0.1194

3.800

0.140

0.1172

3.900

0.140

0.1148

4.000

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Fig. 9 Dimensions assumed for selection of pile foundation parameters

where M U E I

is bending moment in the cross section of the rod; is displacement of the rod; is modulus of elasticity of the rod material; is moment of inertia of rod’s cross section.

The equation of rod bending taking into account (1, 2) is given in the publication of Slivker [23] and can be written as follows: U  + k 2 U = k 2 Uh + (Q h /N )k 2 (h − x),

(3)

k 2 = N /(E I ); Uh = U (h); Q h = Q(h)

(4)

where

The solution to this equation is expressed as follows: U = B1 sin kx + B2 cos kx + Uh + (Q h /N )(h − x)

(5)

where B1 = (Q h /N k); B2 = −(Q h /N k) tan(kh); Uh = (Q h /N k)(tan(kh) − kh)

(6)

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By varying inner and outer diameter of the pipe and its height, acceptable dimensions of poles can be obtained for pre-defined period of oscillation of the seismic isolated building. In the process of selection parameter values are rejected if the condition of strength is not met. Table 1 includes values of above-mentioned parameters for the period of seismic isolation T = 1.5 s, provided that: – design yield strength of steel is 560 MPa; – design ultimate tensile strength of steel is 650 MPa. The results suggest that the most rational design solution is the pole with an outer radius of 11 cm, an inner radius of 7.25 cm, and a height of 3.3 m above the ground surface. Piles with annular cross section have proved to be the most cost-effective solution. Preliminary calculations allow for accepting the appropriate design solution for piles as a final option for the seismic isolation function. The next stage includes more sophisticated calculations based on refined computational models (two-dimensional and three-dimensional) taking into account actual design solution for the building and assumed design of the seismic isolation using state-of-the-art software packages, for example, SCAD, Lira, or other computational software. As noted above, performance of the seismic isolation system is dependent to a significant extent on the presence of additional damping, which is required to limit hazardous displacements of seismically isolated parts of the building under low-frequency impacts. Implementation of damping components, for example, dry friction dampers, is shown in Figs. 5 and 6. It was shown in [14, 22] that for the purpose of oscillation damping friction force in the dry friction damper should be taken equal to 8–15% of the structure weight. Also, guidelines are given for taking into account dry friction forces in seismic isolation systems. In particular, it is noted that the friction force can be taken as follows: F = 0.1 mg

(7)

where g is acceleration of gravity; ƒ is estimated friction factor (ƒ = 0.1); and it can be replaced by equivalent viscous factor of non-elastic resistance, γ, which is dependent on oscillation amplitude, u γ =

where



4 fg , π ku2 u

(8)

cu is fundamental frequency of building/structure oscillation. m The suggested approach to damping forces evaluation makes considerably simpler the procedure of calculation and substantiation of the seismic protection system in question. Ku =

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The data in Table 1 shows that selection of piles for seismic isolating foundation is not a simple task. The load on poles can be reduced significantly by linking them with a friction-moving joint. In this case, the grill can slip in relation to pile heads and its absolute displacement can be bigger; however, the displacement of pile heads and acceleration of the building will be considerably lower. Figures 10 and 11 show examples of calculation of displacements and accelerations of the grill under the impact defined by the Bucharest earthquake of 1978 (Incherk) for the friction force

Fig. 10 Spectrum of displacements in case of normal a joint between piles and grill plate without additional damping (red curve) and with additional damping (black curve) as defined by the Incherk earthquake, and in case of friction b joint between piles and grill plate

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Fig. 11 Spectrum of accelerations in case of normal a joint between piles and grill plate without additional damping (red curve) and with additional damping (black curve) as defined by the Incherk earthquake, and in case of friction b joint between piles and grill plate

in friction joint equal to 30% of building weight. Figure 10 shows full displacements of the grill with Fig. 10a showing the displacements in case of rigid joint between piles and grill without any additional damping and with additional damping equal to 25% of the critical value.

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3 Conclusion The analysis of geotechnical and seismic conditions of the Baikal–Amur Mainline construction suggests a sophisticated nature of their combined manifestation, which includes the presence of permafrost, high seismic activity, and severe climate. Currently, certain requirements are formed as related to ensuring strength and stability of transport infrastructure facilities, which are reflected in regulatory engineering documents and proved by the practice of construction in the area of the Baikal–Amur Mainline. Taking into account the peculiarities of earthquake manifestation on the ground surface, their diverse frequencies, high intensity, unpredictability, repeatability, and other factors, it should be considered that in order to improve earthquake resistance of transport infrastructure facilities, it is reasonable to apply special means of seismic protection in the form of seismic isolation and seismic damping. These measures should be taken with due account for the design solutions selected for permafrost conditions, for example, the use of pile foundations with elevated grill as a solution preserving frozen state of soils in accordance with principle I and as components of elastic link during seismic impact. To select proper parameters of the special seismic protection in the conditions of permafrost, a simplified assessment method is suggested for pile foundations with elevated grill that perform the function of ductile connection between the base and the building. Recommendations are given as related to taking into account damping forces in designs of the selected seismic isolation. In order to reduce the loads on seismic isolating members, it is reasonable to implement friction-moving joint between the grill and pile heads.

References 1. Solonenko VP (1979) Seismology and seismic zoning of the BAM route and its economic influence zone. Nauka, Siberian Branch, Novosibirsk 2. Solonenko VP (1981) Seismological conditions of the BAM construction area. Irkutsk Region Publishing House No. 1, Irkutsk 3. Grib SI (1983) Pile foundations on permafrost soils in seismic areas. Stroyizdat, Leningrad Division, Leningrad 4. Soloviev VS et al (1980) In: Fedorov DI (ed) Transportation buildings. Transport, Moscow 5. Solonenko VP (1964) Earthquakes and volcanoes of the Stanovoe upland. Priroda 9:102–110 6. Chemezov EN, Petrov AF, Blinova TE (2007) On seismic hazard on the territory of Yakutia. In: Vestnik of M.K. Ammosov North-Eastern Federal University, vol 4, no 3, pp 33–38 7. Polyakov SV (1978) Consequences of Severe Earthquakes. Stroyizdat, Moscow 8. TASS Home Page. https://tass.ru/proisshestviya/5857956. Access date 2018/12/20 9. Recommendations for Design and Construction of Continuous and Pile Foundations of Buildings for Transport Purposes in Conditions of Permafrost Soils and Seismic Activity. Central Institute of Scientific Information on Construction and Architecture (TsNIIS), Moscow (1976)

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10. Recommendations for Spatial Arrangements and Structural Solutions of Buildings for Transport Purposes in Conditions of Permafrost Soils and Seismic Activity in the BAM Area. Central Institute of Scientific Information on Construction and Architecture (TsNIIS), Moscow (1975) 11. Kotov PI, Roman LT, Sakharov II, Paramonov VN, Paramonov MB (2015) Influence of thawing conditions and type of testing on deformation characteristics of thawing soil. Soil Mech Found Eng 52(5):254–261 12. Rempel AW (2007) Formation of ice lenses and frost heave. Earth Surf USA 70–76 13. Torre Jorgenson M, Racine CH, Walters JC, Osterkamp TE (2001) Permafrost degradation and ecological changes associated with a warming climate in Central Alaska, vol 48, no 4. Springer International Publishing AG, pp 551–579 14. Uzdin AM, Elizarov SV, Belash TA (2012) Earthquake-resistant structures of transport buildings and structures. Federal State Budgetary Educational Institution “Educational and Methodical Center for Education in Railway Transport”, Moscow 15. Eisenberg YaM, Gaiyrov BK, Katyshev MK, Melentiyev AM, Nemykin AN, Neimark LI, Podgorny VA, Smertin OS (1987) New effective solutions for seismic protection of buildings for construction in the complicated soil and geological, seismic, and climatic conditions of BAM and South-Yakutian Coal Field. Abstracts of reports of the All-union meeting (field session) “Seismicity, Geological Engineering, and Ground Water Hydrology of the BAM Zone”, pp 31–33. The Institute of Earth’s Crust, Siberian Branch of AS USSR, Irkutsk 16. Eisenberg YaM, Deglina MM, Mazhiyev KhN et al (1983) In: Eisenberg YaM (ed) Seismic isolation and adaptive seismic protection systems. Nauka, Moscow 17. Kharitonov VA (1978) Aseismic construction in areas of permafrost soil propagation. Central Institute of Scientific Information on Construction and Architecture (TsNIIS), Moscow 18. Belash TA, Sergeyev DA (2016) Implementation of principle of seismic isolation in buildings on permafrost soils residential construction. Zhilishchnoe Stroitelstvo Magazine No. 1–2, pp 47–50 19. Belash TA, Nudga IB, Sergeyev DA (2014) Foundation of aseismic building: patent 145799, Russian Federation, IPC E 04 H 9/02/; applicant and patent owner: Federal State-Funded Educational Institution of Higher Professional Education Emperor Alexander I St. Petersburg State Transport University, No. 2014120020/03; application made on 19.05.2014; published on 27.09.2014, Bulletin No. 27 20. Stepanova EV, Nudga IB, Sandovich TA, Al-Naser M Author’s certificate No. 1604937 [USSR]. Antiseismic support device Application made on 21.01.89, (21) 4657464/31–33; published on 07.11.90, Bulletin of Inventions No. 41, IPC E0201 27/34; E04H 9/02 21. Elizarov SV, Lugovaya EV (2005) Foundation of aseismic building: Utility model patent No. 46517, application 2005103717/22 dated 11.02.2005; published on 10.07.2005, Bulletin No. 19 22. Belash TA (2017) Non-traditional methods of seismic protection of transport buildings and structures. Federal State Budgetary Institution of Extended Education “Training and Methodological Center for Education in Railway Transport”, Moscow 23. Perelmuter AV, Slivker VI (2007) Stability of equilibrium of structures and related problems, vol 1. Moscow

Creation of the Massif of Permafrost in Construction Zones of Engineering Structures on Soft Soils V. I. Moiseev, T. A. Komarova, O. A. Komarova and N. K. Vasiliev

Abstract This paper considers a solution of the task of artificial months-long cooling of soft soil under a layer of fallen snow in zones of engineering structures located in close proximity to industrial sources of thermal energy (thermal power plants, heat power main lines, the oil processing enterprises, etc.) in northern regions. Operation of industrial sources of thermal energy in northern regions of Russia is complicated by the fact that extensive territories of these regions are boggy and are covered with permafrost. Work of an industrial source of thermal energy causes thawing and weakening of soil with all negative consequences that follow. The method of monthslong (during all winter season) cooling and thermal stabilization of soil under a layer of the fallen snow and of maintaining of negative temperatures of soil during the spring-summer period is offered. Besides, the device that provides realization of such a method is described. In operation of the device the fact that snow and ice have high ability of reflecting of solar radiation, low heat conductivity and very big warmth of phase transition from a firm state to a liquid state is used. Snow and ice on the cooled sites do not manage to thaw during summertime, and in the next winter their mass increases at the expense of the fallen rainfall. Within several years in swamps the strong ice-soil massif (a peculiar artificial massif of permafrost), which can exist tens and hundreds of years, is formed. This artificial massif of permafrost is planned to be used as the basis for construction of industrial facilities of houses, sites of railroad tracks, port constructions, etc. Keywords Artificial massif of permafrost · Soft soil · Frozen soil · Thermal stabilization · Northern regions

V. I. Moiseev Emperor Alexander I State Transport University, 9, Moskovki Ave, 190031 St. Petersburg, Russia T. A. Komarova · O. A. Komarova Scientific Center DISIST, Novocherkaski Ave., 40, 195112 St. Petersburg, Russia N. K. Vasiliev (B) JSC Vedeneev VNIIG, Gzhatskaya St. 21, 195220 Saint-Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_10

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1 Introduction The development of the territories in the North and East of Russia by the constructing of various engineering facilities and structures, encounters numerous difficulties. The difficulties are associated with particularly difficult natural conditions characterized by the spread of permafrost, freezing of marshy ground in winter and their deep thawing in summer. Numerous studies and monitoring conducted by various research and design institutes, such as « Lengiprotrans » , « Sibgiprotrans » , « Tomgiprotrans » and a number of others, as well as leading scientists, experts in this industry, allowed to draw conclusions about the reasons of deformations of the earth road beds in areas of permafrost [1]. The reasons are: 1. Deformations are caused by perennial thawing and sedimentation of soils at the base of the road bed, and the deformations are directly related to the depth of thawing. It is known that soils in the frozen condition possess high strength parameters but during summers the soils are in the thawing condition in which they are very weak. 2. Progressive thawing is most likely to occur under high and wide embankments, and the permafrost degradation occurs under conditions, when the average annual temperature of soils becomes positive. 3. Permafrost degradation, largely due to low albedo (10–15%) of solar radiation of coarse gravel, which lie at the base of the road bed. 4. In conditions when the seasonal freezing depth is less than the height of embankments, taliks with a thickness of several meters are formed in the body of high embankments, and zones of long-term thawing of the foundation soils form under the embankment. Having considered these reasons the most effective direction is to solve the problem of year-round maintenance of low temperatures of permafrost soils under an earthen road or railroad bed, as well as under industrial facilities, buildings and structures. This direction is connected with the need for intensive cooling of soils under the layer of snow and ice during the whole winter and spring time. It should lead to a layer of snow and ice on the surface of the earth for as long as possible (ideally during the whole summer period). Ice and snow have a high (more than 80%) albedo of solar thermal radiation, a sufficiently low thermal conductivity (λ = 0.35–2.2 W/(m·K) and a very high specific heat of fusion (r = 330 kJ/kg). All this makes it possible to use them as obstacles to the spread of heat fluxes from the atmosphere into the ground in summer time. At present, the freezing of soft soils is ensured by the organization of a pile field, made from the means of thermal stabilization of soils (thermosyphones) installed in the foundations of buildings and structures, under railways and highways [2, 3]. Thermosyphones usually consist of pipes plugged at the bottom and filled with fluid coolant, e.g., kerosene. The operation of thermal stabilization devices involves

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transferring of natural cold to the foundation bottom to maintain constant negative temperatures in the permafrost, so that the heat coming from the structures or from natural processes is balanced. The thermosyphones require no power cost and automatically start working due to the difference of temperature between the soil and outside air. The applicable scope of thermal stabilization devices is wide: linear structures; engineering structures; buildings, including civil engineering applications; and hydraulic engineering structures. It is shown [1] the thermosyphones are not effective in transport construction in comparison with other methods. Over the spring and summer period, however, when permafrost soils weaken, thermosyphones do not work [2]. The fluid in the pipes congeals into a stable, laminated condition; and its circulation stops. Also, the practice of operating the thermosyphones shows that with a decrease in the temperature difference between the atmosphere and the cooled soil to the equivalent thermal conductivity provided by the coolant, it becomes already negligible. Thermosyphones freeze soil only at the beginning of winter and only at very hard frosts. Certainly the summer thawing of frozen soils creates difficulties in the building and operating of structures in the northern regions. One of the simplest solutions for the prolonged freezing of soft soils in the northern regions is offered and the description of the offered method is provided below.

2 Description of the method Any industrial facility operated in the northern regions has a heat supply source, for example, a thermal power plant, a boiler house, or other facilities that have a pipe 1 for discharging exhaust gases which are warmer than the atmosphere. The offered method for the prolonged freezing of soft soils with creation of the strong massif of permafrost was founded on the usage of the energy of the heat supply sources. A schema of the device that provides realization of the method is shown in Fig. 1. The device consists of a horizontal pipe system, vertical tube and shutter. A horizontal pipe system 2 is laid underground, and its schema is shown in Fig. 2. In the autumn—winter period, the thermal power plant or boiler house begins to operate according to its intended purpose. At the same time, hot exhaust gases are discharged through the pipe 5, they heated gas located inside the pipe 3. With the beginning of steady frost, the shutter 4 opens, and an upward air flow occurs inside the pipe 3, causing movement of cold atmospheric air through the system of horizontal pipes 2 located in the ground under a layer of snow 6. With the onset of spring, the shutter 4 closes the air intake to vertical tube 3. Consider the case when three parallel pipes A, B and C, with the same diameter d, are immersed in the ground, with a known thermal conductivity λ at a depth h from the surface, with the distance between the axes of the pipes S (Fig. 2).

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Fig. 1 A schema of the simplest solution for the prolonged freezing of weakened soils in the zone of construction or operation of buildings. 1—soil; 2—horizontal pipe; 3—vertical tube; 4—shutter; 5—thermal power plant pipe. B1, B2, B3—industrial buildings and facilities

Fig. 2 A schema of horizontal pipe system. 1—soil; 2—horizontal pipes; 6—layer of snow

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In the further analysis, heat transfer from a series of parallel-laid pipes into an array is considered by the joint application of the method of “heat sources” and the “principle of superposition”, which is described in [4]. We assume that with the passage of atmospheric air through each of the pipes 2, its temperature T tp is maintained constant in time and the same at all points of the pipe, the surface temperature of the array T 0 is also considered constant. The specific thermal conductivity of clay thawed and frozen soils is in the interval λ = 1.12–1.38 W/(m K). When d = 0.3 m, h = 1.5 m, and S = 2 m, we get S/d = 9 and h/d = 5. , the isothermal heat flow line from the soil mass 1 to the At cooling pipe 2 can be taken as a circle which is coaxial to the pipe. Each pipe 2 is considered as a cooling element with the linear specific thermal flux ql , W/m. This value is determined by the well-known formula used to calculate ql from pipes into the ground: ql =

2π λ(TTp − T0 )    2h 2 ln 2h + − 1 d d 

At d = 0.3 m, h = 1.5 m: 

2h d

2

ql =

= 100 >> 1 2π λ(TTp − T0 )

ln 4h d

At T tp = −20 °C i T 0 = 0°C, ql = 60 W/m. The value of linear specific thermal flux provides the flow of air moving through the pipe 2. The speed of air flow V is determined by the formula: V =

ql dρc(T0 − TTp )

Substituting the density values ρ = 1.2 kg/m3 , specific heat capacity C = 103 J/kg K of air, the calculated value ql from previous formula and at T 0 = 0 °C, T tp = −20 °C, we get a rather small value of speed of air flow about 8.0 cm/s. This speed can be achieved by heating the air in the vertical pipe 3 with flue gases passing through pipe 5 from thermal power plant. The thermal resistance R of the massif of soil surrounding the pipe system shown in Fig. 2 is determined by the well-known [5] formula: 1 R= ln 2π λ



  2    4h 2h 1 2h 2 · 1+ · 1+ d S 4 S

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Fig. 3 Change of thermal resistance of soil massif to the cool thermal flux created by three parallel pipes

In the last formula the first factor in the square brackets corresponds to the thermal resistance of the massif to the cool thermal flux created by one pipe A, the other parts correspond to the change in thermal resistance of the massif due to the presence of two symmetrically arranged pipes B and C (see Fig. 2). Figure 3 shows the thermal resistance of the soil with a block cooling tubes A, B and C with specific thermal conductivity of soil λ = 1.12 W/(m K), calculated by the last formula for various h/d and S/d. It can be seen that the thermal resistance R decreases with increasing distance between pipes S/d and increases with depth h/d. For reasons of operation, the depth of laying the pipes should be at least 1–1.5 m, at h/d = 5 and S/d = 10 the thermal resistance R of the soil massif to the cool thermal flux is 0.68 K/W·m. The temperature distribution in a solid massif of soil in the vicinity of the block of cooling tubes A, B and C is determined by the next equation [5]:  T (x, y) − T0 = TTp − T0

ln

x 2 +(h+y)2 x 2 +(h−y)2

+(h+y) · (x+s) (x+s)2 +(h−y)2     2 2 ln 4 dh 1 + 2 hs

·

(x−s)2 +(h+y)2 (x−s)2 +(h−y)2

2

2

The results of calculations using this equation are shown in Fig. 4.



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Fig. 4 Temperature distribution in the massif of cooled soil

Calculations for steady-state regime according to the formula (5) show that when passing through pipes 2 for 120 days in cold air with a temperature of T air = −20 ° C, all the soil down to the surface of its section with a layer of snow 6 is cooled to temperatures not higher than T = −10.5 °C. Such a low soil temperature, plus low thermal conductivity and high reflective snow in layer 6 suggests that negative temperature of the frozen soil will remain for a period of not less than 50–60 days, i.e. all summer.

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3 Conclusion • The method of months-long (during all winter season) cooling and thermal stabilization of soil under a layer of the fallen snow and of maintaining of negative temperatures of soil during the spring-summer period is offered. • The offered method for the prolonged freezing of soft soils with creation of the strong massif of permafrost is developed. • Calculations show the offered method allows for the creation of the strong artificial massif of permafrost in construction zones of engineering structures on soft soil and this massif does not thaw during whole summer. • This artificial massif of permafrost is planned to be used as the basis for construction of industrial facilities of houses, sites of railroad tracks, port constructions, etc.

References 1. Kondrat’ev VG (2009) Construction experience and stability problems of the Qinghai-Tibet railway in the permafrost areas. Transport Russian Federation 6(25):52–55 (in Russian) 2. Agostini B, Habert M (2013) Compact thermosyphon heat exchanger for power electronics cooling. J Energ Power Eng 7(5):972–978 3. Shespari M, Khalilzad S (2016) A review on permafrost geotechnics, foundation design and new trends. Int J Res Eng Sci 4(10):59–71 4. Pehovich AI, Gidkikh VM (1976) Calculations of thermal regime of solids. Energia (in Russian) 5. Shorin SN (1964) Heat transfer. Vushaya shkola (in Russian)

Research of Ribbed Piles in Permafrost Naberezhnyi Artem , Kuzmin Georgiy

and Savvina Aleksandra

Abstract The article presents the results of studies of ribbed and smooth pile models when interacting with various types of soil solutions based on cement and calcareous binders with filling of sand and borehole cuttings (sandy loam). Pile models were tested for indentation in the Underground Laboratory of the Permafrost Institute SB RAS. The behavior of near-pile soil when interacting with a ribbed and smooth pile surface is investigated. Tested models of ribbed and smooth piles in cementcalcareous-soil solution with the addition of a plasticizer. The mobility of the solution was studied and the existing of voids under the ribs with a solution was considered. Keywords Permafrost · Frozen soils · Ribbed piles · Bearing capacity · Soil strength · Soil solutions

1 Introduction Boring piles, which are currently widely used in the construction of buildings and structures on permafrost of Russia, have low efficiency in the use of the bearing capacity of frozen soils, which we indicated in the previous article [1]. The bearing capacity of the smooth piles base is mainly provided by the shear strength of the soil solution along the lateral surface of the co-freezing with the pile. Currently, there are many design solutions to increase the efficiency of using the frozen soils strength characteristics [2–7], but in our opinion, the most rational is the use of a ribbed side surface. When using boring piles with a ribbed side surface, the soil solution and the surrounding soil mainly work in compression [8], as a result of which the base bearing capacity increases. This will lead to a decrease in the depth of the pile or to reduce their number. N. Artem (B) · S. Aleksandra North-Eastern Federal University Named After M. K. Ammosov, 677000 Yakutsk, Russia e-mail: [email protected] N. Artem · K. Georgiy Melnikov Permafrost Institute, SB RAS, 677010 Yakutsk, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_11

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The studies we conducted earlier revealed the dependence of the base bearing capacity on the pitch of the ribs and the angle of their inclination. According to many scientists [9–15], when using boring piles a significant impact on the bearing capacity of the base is exerted by the strength and technological characteristics of the solution for pouring into the borehole. The change in the base bearing capacity of ribbed piles with various soil solutions was not previously investigated, which determined the direction of our study. In addition, we conducted a study of the nature of soil deformation in the near-pile zone after testing. When using ribbed piles, there is a risk of voids in the solution under the ribs, so we also investigated the interaction of the ribbed piles with the solution when using a plasticizer.

2 Methods Experiments on the pressing loads were performed on a metal frame consisting of two columns with horizontal beams (Fig. 1) of channels No. 14. Columns and beams have perforations for the installation of bolts. A soil sample with a frozen pile and a Fig. 1 Frame for pile testing

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dynamometer was installed on the lower beam. The magnitude of the pile deformation was measured using a dial gauge. The pressing load on the pile models was created by a hydraulic jack, which rested against the upper frame beam. The frame is placed in the Underground Laboratory of the Permafrost Institute SB RAS. The laboratory has a constant temperature of −3 °C. The samples were frozen in circular pipes with a diameter of 325 mm and a wall thickness of 8 mm, to which a smooth rebar with a diameter of 12 mm was welded to fasten a dial gauge using a system of rods having three degrees of freedom for easy fixation. Pile models are made of wood with a cross-section in the shape of a circle with a diameter of 60 mm. The models are made of wood because of the simplicity of their manufacture. In addition, according to SP 25.13330.2012 “Foundations on permafrost soils” the freezing factor γaf for the material is 1 for wood and concrete, and 0.7 for metal. Volokhov [16] notes that in the study of materials such as tape, steel and concrete, the strength of co-freezing increases in the series: tape-steelconcrete for all the studied soils and temperatures. In studies of freezing plywood, steel, textolite and plexiglass with various frozen soils, conducted by Surikov [17], it is noted that the greatest resistance to shear was observed for glued plywood when interacting with all types of soils, which is explained by its “increased roughness and swelling due to soil moisture”. To study the nature of deformation of the near-pile soil, a technique was used that was applied to the helical piles closest to the proposed solution. For example, Akopyan [18] conducted an experiment in a flat formulation (using a flat tray), which resulted in a relationship between vertical force and vertical movement of the model, and also revealed a general picture of the deformation of near-pile soil in the process of loading with exploitation loads. Aksenov [19] used frozen multicolored clay, according to the nature of the deformation of which conclusions were made about the size of the array of near-pile soil involved in the work. In our case, with stepincreasing loads, the nature of the deformation of the soil could not be recognized due to minor vertical movements. After testing, samples with soil were cut. As a result, the samples were tested for conditionally instantaneous strength of the soil and were cut after testing. The nature of the deformation of the soil was studied on models of smooth and ribbed piles with a pitch of ribs 1/3 and 5/12 of the pile diameter and the angle of the ribs inclination 45°. For testing models of piles with solutions, models of piles with a pitch of 1/3 of the pile diameter and the angle of the ribs inclination of 55° were tested. Calcareous-sand, calcareous-soil, cement-sand, cement-soil solutions are used as borehole fillers. Sand for cement-sand and calcareous-sand solutions has a fraction of 1 mm. For cementsoil and calcareous-soil solutions was used borehole cuttings. The composition of the soil was determined according to GOST 12536-2014 “Soils. Laboratory methods for determining the grain-size (grain) and micro aggregate composition”. The granulomere composition of the borehole cuttings is as follows: the content of clay particles is 1.15%, sand particles is 96.3%, dust particles is 2.55%. The overwhelming majority of piles in permafrost are installed using a borehole inlet technology, therefore, to imitate it when the soil was poured, a “borehole” with a diameter of 70 mm was left. The soil was frozen in a freezer at −20 °C, then kept at −3 °C. After the soil

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Table 1 Solution compositions for 300 ml volume Solution

Sand, g

Cement-sand

249

Cement-soil Calcareous-sand Calcareous-soil

Borehole cutting (sandy lime), g

Cement, g

Limy dough, g

135 249

400 400

Water, ml 123

135

123 99.3

89

93.9

89

freezes in the “borehole”, a model of a pile with a subsequently removed support was installed to exclude the work of the soil under the lower end of the pile, the free space between the wall of the “borehole” and the pile was filled with a solution. The solution’s composition is described in Table 1. The samples were kept until the surrounding temperature was set and covered with the plastic tapes to exclude the sublimation process. When using ribbed piles there is a risk of formation of voids in the soil solution. To eliminate this danger, we considered the following options: the use of vibratory pile drivers or the use of a plasticizer. The use of vibratory pile drivers will lead to an increase in the labor intensity of installing the pile and, consequently, an increase in the cost of constructing foundations. Therefore, we propose the use of a plasticizer to improve the plasticity and workability of the solutions. According to the above method, we tested samples with concrete models of smooth and ribbed piles under compressing step-increasing loads. Solution applied cement-calcareous-soil. The plasticizer was used brand “Polyplast PFM-NLC”, which consists of: a hydrophobic component with sodium salts, polyethylene-naphthalene sulfoxylot, air-entraining component. The solution has the following composition: Portland cement 12%, lime 6%, borehole cuttings 66%, water 16%. Tests of samples with cement-calcareous-soil solution with the addition of a plasticizer were carried out similarly to tests with other types of solutions, but on concrete models of piles, the material of which is closest to the material of full-scale piles. The cross-section of the pile models is square with the main dimensions of the outer contour: width 40 mm, height 150 mm. The parameters of the ribbed pile: the height of the ribbed part is 102 mm, the rib pitch is 20 mm, the angle of the ribs inclination is 55°. The pressing load was created with the help of lever presses, which made it possible to set the static load without compensating for the pressure loss during the vertical movements of the piles. The load was set in steps according to GOST 5686-2012 “Soils. Field methods for testing soils via piles”. In addition, the mobility, brand strength and density of the solutions were determined according to GOST 5806-85 “Building solutions. Test methods”.

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3 Results Studies on the nature of deformation of the near-pile soil showed that between the ribs of piles with a rib pitch of 1/3 of the pile diameter there is a shift in the intercostal part of the soil (Fig. 2). The same deformation of the soil was noticed by Aksenov et al. [19] when testing models of screw piles and was conventionally called “clear compression”. It is noted in the work that the deformation of the layers involved by the helixes (ribs) of the pile occurs, apparently, at the shear stage, since at loads less than the compressive strength of the soil, such deformation of the layers should not occur. A similar view is shared by many Russian and foreign scientists [20–26]. In our case, “clear compression” does not show up itself due to the inclination of the ribs. Observing the deformation nature, we can state that initially, the soil worked mainly for compression, and after the onset of the limiting state of the soil under the ribs, a shift occurred at the stage of progressive destruction. A similar behavior was observed on the soil samples around the pile with the rib pitch 5/12 of the pile diameter. After testing the smooth piles, samples were also cut, on which it was visible that a frozen and deformed layer of soil up to 5 mm thick remains on the lateral surface of the smooth pile (Fig. 3). Tested models of ribbed piles on the base bearing capacity along their lateral surface when the device is based on boring inlet technology with boreholes filled with various solutions. The results of determining the base bearing capacity on the lateral surface of ribbed pile models with borehole filling with various solutions are shown in Fig. 4. Solutions with calcareous and cement binders were tested with a filler of fine river sand and borehole cuttings (sandy loam): cement-sand, cement-soil, calcareous-sand and calcareous-soil. The samples of models of piles with a cement-soil solution (4539 kg) have the largest bearing capacity, the smallest—with a calcareous-sand solution (3631 kg) with a difference of 25%. Samples of models with cement-sand and calcareous-soil solutions have a carrying capacity of 4179 and 3888 kg, respectively. Fig. 2 Cut of a ribbed piles sample after testing

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Fig. 3 Cut of a smooth piles sample after testing

The bearing capacity of samples of ribbed piles with soil solution based on borehole cuttings and sand differ slightly (on average, 8% more). This shows that in the case of ribbed boring piles, the composition of soil solutions has a less effect on the base bearing capacity than in the case of smooth boring piles, which can be explained by the fact that the soil solution, in this case, is in a space bounded by the ribs and wall of the borehole, and compressive stresses due to the presence of a certain angle of ribs inclination are transmitted through the solution to the surrounding soils. You can also conclude that the borehole cuttings can be used for the preparation of a soil solution of wells with a device for ribbed boring piles. The tests of wooden pile models for static pressing loads in frozen sands carried out by us earlier [1], showed that the base bearing capacity along the lateral surface of piles can be increased up to 3 times compared to smooth piles depending on the angle of inclination and edge pitch. Therefore, when testing samples with concrete models, we used a rib pitch of 20 mm and an inclination angle of 55°, at which the maximum bearing capacity of wooden piles was obtained. The bearing capacity of the base when using a ribbed pile was 1600 kg, which is 2.3 times higher than when using a smooth pile (700 kg). It should be noted that during the testing of concrete models, the temperature in the underground laboratory was constant and equaled − 5 °C.

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Fig. 4 The results of determining the base bearing capacity on the lateral surface of ribbed pile models in various solutions

In addition, we recorded that when using a plasticizer, water consumption is reduced by 11%, while the mobility of the solution increased by 12.5%. The mobility of the solution when using a plasticizer increased (cone sediment increased from 14 to 16 cm). The section of the samples after testing showed that no pores are formed in the soil solution under the ribs of the pile. However, this circumstance requires verification when it is poured into the boreholes for the installation of full-scale ribbed piles.

4 Conclusion 1. The study of the nature of the soil deformation in the near-pile space showed that when using ribbed piles, there is a shift of intercostal soil. However, the shift occurs at the stage of progressive destruction after the occurrence of the ultimate state of the soil under the ribs. 2. Testing models of ribbed piles in various soil solutions showed that the composition of soil solutions for pouring into boreholes when using ribbed piles has a

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smaller effect on their bearing capacity than in the case of smooth piles. Therefore, it is possible to use cheaper ingredients for the preparation of soil solution, including borehole cuttings. 3. Testing of samples with ribbed and smooth pile models showed that when using a cement-calcareous-sand mortar with a plasticizer, the base bearing capacity along the lateral surface of the ribbed pile will be 2.3 times higher. The use of plasticizer increases the mobility of the soil solution, which is important when using ribbed piles. Cutting of the samples showed that all the voids were filled with a solution. However, this fact needs to be confirmed when used in full-scale piles. Acknowledgements The research was conducted with the support of the Grant of the Head of the Republic of Sakha (Yakutia) for young scientists, specialists and students.

References 1. Naberezhnyi AD, Kuzmin GP, Savvina AE (2018) Investigations of ways to improve the efficiency of the frozen soils bearing capacity of boring piles. In IOP Conf Ser: Mater Sci Eng vol 463. No 3, p 032035 2. Evans AL (2001) A study of an air convection pile, a thermosyphon permafrost protection device: Ph.D.Sc. thesis. Knoxville, University of Tennesee, p 291 3. Assali IF (2003) Thermal analysis and bearing capacity of piles embedded in frozen uniform soils: M.Sc.thesis. Ontario, University of Windsor, p 328 4. Thiyyakkandi S, McVay M, Bloomquist D, Lai P (2013) Measured and predicted response of a new jetted and grouted precast pile with membranes in cohesionless soils. J Geotech Geoenviron Eng August 2013, 1334–1345 5. Li N, Xu B (2008) A new type of pile used in frozen soil foundation. Cold Reg Sci Technol 53:355–368 6. Sego DC, Biggar KW, Wong G (2003) Enlarged base (belled) piles for use in ice or ice-rich permafrost. J Cold Reg Eng June 2003, pp 66–88 7. Design manual for new foundations on permafrost. September 2000, 82 p (2000) 8. Kuz’min GP Zhang RV Remizov VA (2002) Pile foundation of manufacturing method for permafrost. Patent №2469150 C 1, MPK E02D 27/35 9. Biggar KW, Kong V (2001) An analysis of long-term pile load tests in permafrost from the short range radar site foundations. Can Geotech J 38:441–460 10. Biggar KW, Sego DC, Stahl RP (1996) Long-term pile load testing system performance in saline and ice-rich permafrost. J Cold Reg Eng, September 1996, pp 149–162 11. Holubec Igor (1989) Thread bar pile for permafrost. Nordicana №54, pp 341–348 12. Velly YY, Dokuchaev VV, Fedorov NF (1985) Handbook of construction on permafrost. Leningrad, Stroyizdat, p 552 13. Sego DC, Smith LB (1989) Effect of backfill properties and surface treatment on the capacity of adfreeze pipe piles. Can Geotech J 26(4):718–725 14. Xu G (2009) Effects of frozen soils in site response and lateral behavior of concrete-filled steel pipe pile: M.Sc. thesis. Anchorage, University Alaska, p 101 15. Voytkovskyi KF, Mel’nikov PI, Porkhaev GV, Votyakov IN, Goncharov YuM, Grechishev SE, Zhigulskiy AA, et al (1968) Foundations of structures on permafrost in Yakutia. Moscow, Nauka Publ, p 198

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16. Volokhov SS (2010) Strength of co-freezing of frozen soils with pipeline materials. Soil Mech Found Eng 5:25–28 17. Surikov VV (1979) Mechanics of frozen soils destruction. Leningrad, Stroyizdat, p 128 18. Akopyan VF (2012) Tests of helical pile models. Engineering bulletin of Don (2012) 19. Aksenov VI, Gevorkyan SG, Iospa AV, Krivov DN, Shmelev IV (2016) Behaviour of helical piles in frozen soils. Electron Sci Ed Alm Space Time 11(1) 20. Vesic AS (1971) Breakout resistance of objects embedded in ocean bottom. J Soil Mech Found Div 97(SM9) pp 1183–1205 21. Mitsch MP, and Clemence SP (1985) The uplift capacity of helix anchors in sand. American society of Civil Engineers, New York, pp 26–47 22. Zhang DJW (1999) Predicting capacity of helical screw piles in Alberta soils: M.Sc. thesis. Edmonton, University of Alberta, p 304 23. Sakr M (2009) Axial and lateral behaviour of helical piles in oil sand. Can Geotech J 46(9):1046–1061 24. El Sharnouby MM and El Naggar MH (2012) Field investigation of axial monotonic and cyclic performance of reinforced helical pulldown micropiles. Can Geotech J 49:560–573 25. Megin ID, Prokop’ev NYu, Tseeva AN (2016) Investigation of behavior of helical piles in various permafrost-soil conditions and development of recommendations for their use in permafrost. Modern problems of construction and life support: safety, quality, energy and resource saving, pp 340–348 26. Cuthbertson-Black R (2001) Interaction between a flighted steel pipe pile and frozen sand: M.Sc. thesis. Winnipeg, University of Manitoba, p 140

The MonArc Project: Monitoring Programme for Foundation Settlements and Initial Results Anatoly O. Sinitsyn, Pavel I. Kotov and Arne Aalberg

Abstract Initial results of the Monitoring of Arctic Infrastructure project (MonArc) are presented. The project surveys buildings in several small towns in Spitsbergen, in the Svalbard archipelago, focusing on vertical settlements of buildings and foundations. The survey programme comprises damage characterization and performs annual measurements of vertical foundation settlements by differential leveling. Ground conditions in Spitsbergen are characterized by continuous permafrost. The monitoring programme comprises measurements in the small towns of Longyearbyen, Barentsburg, Pyramiden, and Svea. Settlement developments for surveyed buildings in the period 2017–2018 are presented. The established data may serve as a reference for future comparison and long-term assessment of vertical movements, for instance by repeating the survey every 5–10 years. The study and the data may contribute to a better understanding of the practical consequences of climate change, with its impact on various infrastructures. Keywords Arctic · Infrastructure · Permafrost · Climate change

1 Introduction Climate change is considered one of the major global challenges for humanity in the twenty-first century. Projected climate changes are most pronounced in the polar regions. It is believed that the impacts on permafrost conditions in the Arctic may lead to significant damage to infrastructure. Consequences of a warmer climate include the warming and thawing of permafrost, an increase in active layer thickness, and A. O. Sinitsyn (B) SINTEF Community, S P Andersens veg 5, 7031 Trondheim, Norway e-mail: [email protected] P. I. Kotov Faculty of Geology, Lomonosov Moscow State University, GSP-1, Leninskie Gory 1, 119991 Moscow, Russian Federation A. Aalberg The University Centre in Svalbard (UNIS), Pb. 156, 9171 Longyearbyen, Norway © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_12

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reduction in soil strength, leading to an increased amount of settlements. As pointed out by [1, 2], the effects of construction and maintenance of infrastructure at a site may also significantly affect the local thermal regime within the permafrost ground and may add to issues regarding the stability of foundations. Long-term field measurements are useful in the design and documentation of the performance of foundations. The results of systematic monitoring of vertical positions of foundations, in conjunction with records of hydrometeorological parameters and maintenance history of a building, may help to identify the primary factors causing severe damage to foundations or a decrease of building serviceability. The Monitoring of Arctic Infrastructure (MonArc) project creates and facilitates research cooperation between Norwegian and Russian researchers in Svalbard. This is through a joint effort in monitoring of selected infrastructure, focusing on vertical settlements of foundations and the development over time. These may be the results of natural creep processes of frozen soil, and accelerated creep and deformations. This is due to warming by climate change and also the possible impact from human activities at the sites, increased amount of surface water, water accumulation, unintended effects of maintenance, heat transported into the ground from buildings, etc. The MonArc project tasks consist of monitoring the elevations of installed points on certain parts of selected buildings—mostly foundation piles in the towns of Longyearbyen, Barentsburg, Svea, and Pyramiden. Svalbard is well suited for the present study as the ground is characterized by permafrost, and several building types and foundation systems are easily accessible. At the same time, climate projections suggest significant climate warming towards year 2100 [3, 4]. Permafrost is continuous in Svalbard [5], with ground temperature at a depth of zero annual amplitude of approximately −2 °C in the proximity of the shoreline (as reported by [6] for Vestpynten near Longyearbyen), and approximately −5 °C in the valleys (for instance Adventdalen near Longyearbyen [7]). Permafrost is usually saline in the coastal zones in Svalbard, posing significant challenges for proper foundation designs.

2 Methods The main operation during the geodetical monitoring of the chosen structures was collection of elevation data for points fixed on the buildings. This data can be used for assessment, analysis, and forecast of settlements of the structures. Methodology for data processing was presented in [8]. Changes of elevations of the monitoring points in relation to each other or in relation to stable reference points were the decisive parameters. Vertical displacements of the monitoring points were determined. Vertical displacement was defined according to the standard [9], i.e., the movement of the monitored point relative to an anchored and stable reference point (a “fixed point”).

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Two main parameters are controlled during the monitoring programme for newly built structures ([10], Table L.1): (i) settlements of foundations and (ii) relative difference of settlements. These parameters were represented by [9] 1. Absolute value of displacement: SHi = Hi − H0 ,

(1)

H0 elevation of monitored point in initial (zero) monitoring cycle. Hi elevation of the same point in i- monitoring cycle 2. Relative difference of displacement of monitoring points: η=

(Snm )i L

(2)

L distance between two monitoring points. (Snm )i difference between displacements of monitoring points n and m in one cycle of measurements i (unevenness of displacement), calculated as follows: (Snm )i = (Sn )i − (Sm )i ,

(3)

The initial elevations of the monitoring points on the building foundations were determined by performing a standard manual differential leveling. This basic method is widely used due to several advantages. It only requires simple and inexpensive equipment, allows measurements under difficult conditions, and provides high accuracy and rapid measurements. Requirements (procedures and tolerances) for such works are found in standards for monitoring of infrastructure [11, 12]. It was presumed that elevations of the reference points were constant in all annual cycles of the monitoring. The assumption requires verification; hence, several reference points were used in some locations, and the data were cross-checked. Ideally, the reference points should be on solid rock or rock-anchored fixed points, as sought in similar investigations on the mainland. This was not present near all the monitored sites in Svalbard. Another option would be to establish new reference points for deformation monitoring in permafrost following typical design presented in [13]. The elevations of the reference points were considered to be constant if the change of the excess between the reference points K was according to (4): K < 2m CT · 2n 0,5 n quantity of stations by one measuring way m CT mean square error of determining the excess of stative (station)

(4)

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Assessment of settlements can be based on the comparison of results with maximum allowable deformations of foundation bases [10]. Depending on the type of frame, deformations can be accessed via: 1. Maximum allowable absolute settlement sumax . 2. Average settlement s u . 3. Maximum allowable relative difference of settlements (s/L)u .

3 Description of Surveyed Buildings The Digital Level Leica Sprinter 250 M instrument and a barcode staff Leica GSS 111 rod were used for the survey. Leveling between a reference point and a building was performed in forward and reverse directions using approximately equal distances. Leveling in two horizons, in closed leveling paths around each building was performed. The following works were carried out in 2017–2018: 1. Identification and/or establishment of reference points (fixed ground points) in the vicinity of the buildings. These were points that could not develop significant vertical movement in a long-term (decades) perspective, for example, massive piled concrete foundations in the vicinity of the considered building. 2. Installation of monitoring bolts on the base or foundation structure of the buildings, in easily accessible positions. Bolts were installed on the foundations at the corners of the buildings and at points closely spaced along the building sides and on piles located under the buildings where it was technically possible. The bolts were drilled and hammered into piles or characteristic foundation points at every 4–5 m. The locations of monitoring bolts were chosen based on recommendations from [7]. 3. Leveling of the reference points, leveling from the reference points to the buildings, and leveling of the monitoring bolts. The precision of a level run is described in terms of a maximum allowable error of the closed leveling path. The survey was conducted in accordance with the allowable errors defined in [11]. In order to provide data on a range of foundation solutions, the survey covers new and old buildings. These comprise shallow strip foundations as well as deeper pile foundations. Geotechnical investigations and documentation for the buildings were not available for the project. However, one may assume that the foundations of all surveyed buildings are constructed with the aim “to maintain the existing thermal regime” according to [14], referred to as Principle 1 in [15]. Detailed descriptions of the reference points, the buildings chosen for the monitoring, and the drawings with monitoring points are given in [8]. An overview of the buildings surveyed in 2017–2018 is presented in Table 1.

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Table 1 Buildings surveyed in 2017–2018 Town

Building

Address/location

Longyearbyen

The UNIS Guest House (UGH)

Road 229.05

The building “Elvesletta Byggetrinn 1”

The junction of roads 500 and 503

Barentsburg

The three-storey residential building “Komplex GRZ”

Heliport

Pyramiden

The multi-purpose garage

–

Svea

The two-storey building for temporal residence Barack “Låven”

–

The two-storey building for temporal residence “Barack (Brakke) 2002”

–

The multi-purpose garage/storage, “Magnetittlageret”

–

3.1 Longyearbyen In Longyearbyen, the apartment building UNIS Guest House and the building “Elvesletta Byggetrinn 1” (The Vault Hotel) were surveyed. The former is a twostorey wooden module building, standing on wooden piles deployed in the ground to a depth of ca. 9 m. Crawl space protected by decorative planks allows airflow below the building (sun shelter in summer, cooling in winter). The building is in plan of approximately 15 by 70 m. The building was constructed in 2009–2011. The second building is a three-storey wooden building, founded on 140 by 140 mm square hollow steel sections deployed to a depth of ca. 18 m in drilled holes, with concrete fill. Crawl space here is also sheltered by decorative planks. The building is in plan approximately 16 by 30 m and was finished early 2018. The leveling path was anchored to reference points at the base of the chimney of the power plant in Longyearbyen. One reference point was installed by Geological Survey of Norway and another one by Norwegian Polar Institute. Ground conditions at the power plant are rock; hence, it is expected that the reference points should be stable.

3.2 Barentsburg The three-storey building “Komplex GRZ”, constructed in 1975–1978, was selected for the survey. The building is approximately 50 by 15 m. It comprises a concrete frame constructed from concrete beams and columns, with infill and exterior brick walls. It is supported on concrete piles, with an estimated depth of 10 m into the

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ground. Airflow under the building is restricted by the exterior brick walls. The building has presently visible damage by surface cracks on the northern wall, likely caused by earlier settlements. Two standard reference points (GUGK system), located on the pad of heliport, and one additional reference (a casing of an abandoned borehole) were used for survey.

3.3 Pyramiden A multi-purpose garage built in 1981–1983 was selected for the survey. The building has brick walls and is supported on a concrete frame supported on pillars on concrete piles. Here, the piles are assumed to be 10 m long (standard for that time). The space below the building permits free airflow in the crawl space. The building has cracks on the walls facing west, north, and south. Reference for the height was taken at three casings of abandoned boreholes and the foundation of the new meteorological station near the building.

3.4 Svea In the mining city of Svea, the two-storey barracks “Barack 2002”, “Låven”, and a multi-purpose garage were surveyed. The first two buildings were constructed in 2002 and 2010, respectively, from prefabricated wooden modules supported on a beam frame, on wooden piles. Standard ventilated space and cover planks allow airflow below the building. The main reference point of Svea, located at the entrance of main Store Norske Spitsbergen Grubekompani office, was used as reference in surveys.

4 Results The initial results are built on the data sets for years 2017 and 2018. The data sets are reported in [8] and [16]. Assessment of measurement quality showed that the measurements in 2018 were more accurate (less errors in the leveling paths) than in 2017, for all monitored objects. In several cases, the measurements were with an outcome fulfilling the requirements of accuracy class 1, i.e., the highest (best) accuracy class for such works.

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4.1 Longyearbyen The reference points in Longyearbyen did not change their position relative to each other over the 2017–2018 (fixed points were stable). The survey from the reference points to the buildings fulfilled the requirements of a third-class accuracy in 2017 and first-class accuracy in 2018. The exact change of elevation of the monitored buildings in Longyearbyen in relation to the reference point is thus difficult to derive. Absolute displacements at UNIS Guest House showed that the settlements were up to 7.1 mm, and heave of piles was up to 5.7 mm; maximum relative difference of monitoring points was 0.0007 mm/mm. At the building “Elvesletta Byggetrinn 1”— settlements were up to 2.3 mm, and heave up to 3 mm; only one value (as monitoring points were distributed in most cases more spaced than on neighbouring piles) of relative difference of monitored points was measured –0.0004 mm/mm. These values should be considered as estimates only. Confirmation and more accurate data will become available after the 2019 field season.

4.2 Barentsburg Only a preliminary field survey was performed in Barentsburg in 2017. The results of this survey cannot serve as a solid baseline data set and be compared to 2018 data. More accurate results will come after survey in 2019 also.

4.3 Pyramiden Two out of four reference points in Pyramiden were stable in 2017–2018. Absolute displacement of the monitoring points on the outer walls at the multi-purpose garage showed settlements in the range 0–5 mm. No heave displacement was detected. The largest displacements were found at locations where the drainage of water (collected on the roof) goes into the ground (found in the left corner of the south-facing wall). The relative difference of monitoring points at that corner was up to 0.0003 mm/mm. The former possibly signals that settlements on these foundations occurred together at the same time (due to leakage of hot water for instance) and stabilized afterwards. Another area showing significant settlements was the location where a heavy tank is installed inside on the building, corresponding to a large vertical load.

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4.4 Svea Displacements for the Barack “Låven” from 2017–2018 showed settlements up to 4.1 mm, and heave was detected only on one pile (0.4 mm). For the multi-purpose garage “Magnetittlageret”, the displacements showed settlements up to ca 14 mm, and heave was detected only at one location (ca. 3 mm).

5 Discussion A comparison of obtained settlement data with maximum allowable deformations of foundation bases may be used to estimate the length of lifetime. This could be performed for the UNIS Guest House, the multi-purpose garage in Pyramiden, and the Barack “Låven” as these are structures placed on separate foundation grills supported by piles. This value will be 10–20 cm depending on the material and construction of bottom frame between piles and upper structure. It appears reasonable to assume the initial phase of vertical displacements of the foundations to be finished for the chosen buildings. If the climate and ground conditions remain the same as today and further settlements develop more or less at a constant rate, one can estimate the following: • UNIS Guest House—the maximum settlements will reach 20 cm by 2040. • Multi-purpose garage in Pyramiden—the maximum settlements should have reached 15 cm by the year 2013. • Barack “Låven”—the maximum settlements will reach 20 cm by ca. 2060. Analysis for the building “Elvesletta Byggetrinn 1” is not given as it was recently built. Data for comparative analysis of the building in Barentsburg and Barack “2002” in Svea will be obtained in 2019. Combination of settlements of some piles with frost heave on others may make the deformations more severe. Note that the lifetime estimates above are very rough estimates, presented as inspiration for future research. Other concerns include the decay of foundation and pile material and accelerated climate change, which may have a more severe impact.

6 Conclusions Data for the elevations of marked points on or near foundations of selected buildings in four towns in Spitsbergen were recorded in 2017–2018, and a simple analysis was performed. The recorded elevation data for the building foundations establish a present (“as today”) data set. Rather significant settlements were observed for some of the buildings in 2017–2018, while the settlements were moderate for others. The data will provide a basis for assessing long-time impacts of climate change on infrastructures in permafrost conditions in the future.

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Data are stored in the project archive, which will be freely available from the project web page [17] and from the Research-In-Svalbard (RiS) database [18]. Acknowledgements The authors would like to thank The Research Council of Norway for the economic support through the POLARPROG programme (246757/E10). We also appreciate the contributions from the project partners Lomonosov Moscow State University, Longyearbyen Lokalstyre, Trust Articugol, Store Norske Spitsbergen Grubekompani AS, The University Centre in Svalbard, and SINTEF Building and Infrastructure.

References 1. Instanes A (2003) Climate change and possible impact on arctic infrastructure. In: Phillips M, Springman S, Arenson L (eds) 8th international conference on Permafrost. Balkema publishers, Zurich, pp 461–466 2. Anisimov O, Vaughan D (2007) Polar regions. In: Parry M et al. (eds) Climate change 2007: climate change impacts, adaptation, and vulnerability. Contribution working group II to the fourth assessment report of the intergovernmental panel on climate change, Cambridge University Press, Cambridge, pp 653–685 3. Benestad R et al (2016) Climate change and projections for the barents region: what is expected to change and what will stay the same? Environ Res Lett 11:1–8 4. Forland E et al (2011) Temperature and precipitation development at svalbard 1900–2100. Adv Meteorol 2011:1–14 5. Humlum O, Instanes A, Sollid J (2003) Permafrost in Svalbard: a review of research history, climatic background and engineering challenges. Polar Res 22(2):191–215 6. Guegan E (2015) Erosion of permafrost affected coasts: rates, mechanisms and modelling. Ph.D. thesis. Faculty of engineering science and technology, department of civil and transport engineering, Norwegian University of Science and Technology, Trondheim 7. Gilbert G (2014) Sedimentology and Geocryology of an Arctic Fjord Head Delta (Adventdalen, Svalbard). M.Sc. Thesis. Department of geosciences, faculty of mathematics and natural sciences, University of Oslo, Oslo 8. Sinitsyn A et al (2018) MonArc project report 2017. SINTEF, Trondheim 9. STO SRO-S 60542960 00043-2015 (2015) “Ob’yekty ispol’zovaniya atomnoy energii. Geodezicheskiy monitoring zdaniy i sooruzheniy v period stroitel’stva i ekspluatatsii” (“Geodetic monitoring of buildings and structures during construction and operation”). ROSATOM, Moscow 10. SP 22.13330.2016 (2016) “Osnovaniya zdaniy i sooruzheniy” (Soil bases of buildings and structures), Rosstandart, Moscow 11. GOST 24846-2012 (2011) “Grunty. Metody izmereniya deformatsiy osnovaniy zdaniy i sooruzheniy” (Soils. Methods of measuring the strains of structure and building bases). Rosstandart, Moscow 12. EM 1110-2-1009 (2002) Structural Deformation Surveying, in Engineer Manual. Department of the Army US Army Corps of Engineers, Washington, D.C 13. GKINP (GNTA)-03-010-02 (2012) “Instruktsiya po nivelirovaniyu I, II, III i IV klassov, (Instruction for levelling of classes I, II, II and IV ). Roskartographiya, Moscow 14. Andersland O, Ladanyi B (2004) Frozen ground engineering, 2nd edn. Wiley, New Jersey 15. SP 25.1330.2012 (2012) “Osnovaniya i fundamenty na vechnomerzlykh gruntakh” (Soil bases and foundations on permafrost soils). Rosstandart, Moscow 16. Sinitsyn A, Kotov P, Aalberg A (2019) MonArc project report 2018. SINTEF, Trondheim 17. MonArc home page, http://www.sintef.no/prosjekter/monarc/. Last accessed on 27 Jan 2019 18. RiS database Home page, https://www.researchinsvalbard.no/project/8747. Last accessed on 27 Jan 2019

Soil Dynamics

New Approach of Railway Roadbed State Monitoring Using Broadband Seismometers Galina Antonovskaya , Natalia Kapustian

and Irina Basakina

Abstract The first results of full-scale seismic modeling of a railway roadbed state inspection in areas with complex climatic and geological conditions (Severnaya Railway of the Russian Federation) are presented. Our results demonstrate the fundamental possibility using broadband seismic sensors installed along the railway roadbed to monitor its state continuously. The method is a passive one because it uses train vibrations for roadbed testing. Seismic monitoring parameters show roadbed deterioration, e.g., flooding, ground thawing, etc. An advantage of the proposed approach compared to the other geophysical methods is the possibility of identifying problem areas at the early stage, as well as real-time monitoring of their state and rapid information transmission to a central communication hub. Keywords Railway roadbed · Passive seismic method · Broadband seismic sensor

1 Introduction Further expansion of Russian railroad infrastructure in the period until 2030 [1] is associated with the development of natural resources in the northern and Siberian regions, with special attention to design, construction, and renovation of railway roadbed. Considering the existing railway roadbed were built at different times and according to different standards, its condition is characterized by varying degrees of preservation and a wide variety of structural elements. The railway track is a joint engineering structure where the upper structure and the roadbed are interconnected and work together in different operational and weather–climatic conditions. Changes in the state of one part of the railway track lead to deterioration in the other. As noted in [2], in order to put the railway track in working condition, not only damage to the upper structure of the track must be eliminated, but the damage causes must be discovered and further eliminated. In many G. Antonovskaya (B) · N. Kapustian · I. Basakina N. Laverov Federal Center for Integrated Arctic Research, Severnoj Dviny Emb., 23, 163000 Arkhangelsk, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_13

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cases, the roadbed deformations are of such roots. They include residual and seasonal precipitation, frost heave, displacement, damage or destruction of the roadbed or its elements from vibration impacts of passing trains, and natural factors (earthquakes). However, an integrated multi-method approach to the railway roadbed diagnosis has not yet been developed. As a result, the funds spent on the repair and maintenance of the roadbed do not give the desired effect. According to the Center for inspection and diagnostics of engineering structures of the Branch of the Open Joint-Stock Company “Russian Railways” the defect rate of the roadbed increased by 54% for the period 2009–2016. Some 6.9% of Russia’s railroads consist of defective or deformed sections [3] and they are distributed very unevenly. For example, on the Far Eastern Railway, the share of defective railroad beds reaches 24.6%. Such dynamics are caused by the dependence of the roadbed state on the funds allocated for its repair [4]. Given the increase in the volume of cargo flows, especially in the Northern regions and regions of Siberia with complex ground conditions, the development of method to ensure continuous monitoring of the roadbed state is undoubtedly relevant. In recent years, field methods of roadbed research have been developed, primarily it is static and dynamic testing of ground [5]. It should be noted, despite the effectiveness of these methods, they cannot perform a roadbed continuous monitoring and detect a negative phenomenon at an early stage of its development; these methods are only a one-time diagnosis in dangerous areas. On the other hand, technical solutions to stabilize the roadbed have been developed. For example, sun protective sheets are proposed to be installed on areas of icy permafrost rock mass (see Fig. 1a) or to perform preventive thawing of highly icy massifs with simultaneous replacement of their non-subsiding soils. Such sheets are installed in the places of icy permafrost rock mass distribution along the Amur–Yakut railway [6], a unique thermal insulation system operates on the railway “Ob–Bovanenkovo–Kara” [7]. Another solution is the installation of vapor–liquid thermosyphons working on the principle of a heat pump, “pumping cold” from the air into the upper layer of permafrost and lowering its temperature in the cold season (see Fig. 1b) [6, 8]. This allows to decrease the average annual temperature by 1–5 °C without any energy costs. Also one can use a device ducts inside roadbed (see Fig. 1c). According to [6], the radius of action of the thermosyphon does not exceed 1.5–2 m, but it does not save from roadbed deformations. Nevertheless, the existing problems in ensuring the roadbed safety confirm the fact of insufficient study of this issue. New technical solutions and continuous monitoring systems are necessary, including one adapted to the conditions of the Far North. This article presented the full-scale modeling considered that convincingly proves the possibility of continuous railway roadbed monitoring by passive seismic method. Passive seismic observations are needful today as they do not use special sounding source? They use microseisms, transport moving vibrations, etc. Creating seismic observation system by installing stationary point seismic stations on potentially dangerous (unstable) railway roadbed sections may be a very promising development. Similar large-scale systems, though aimed at early earthquake warning, operate in several countries around the globe (South Korea, France, etc.) [9, 10].

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Fig. 1 Technical solutions for stabilization of railway roadbed: a–sun-protection sheets on the slopes of the Qinghai–Tibetan railway roadbed [6]; Tibetan plateau, China [8]: b–thermal stabilization of the railway roadbed by means of cooling thermosyphons [11], c–ventilation channels inside roadbed [12]

2 Equipment and Survey Methods We conducted field seismic survey of two roadbed sections (dangerous and stable) of the Severnaya Railway in the Arkhangelsk region by using different seismic methods. The peaty soils are developed on the predominant part of the study area. Peat is usually underlain by weak grounds. Therefore, pile supports are usually installed on such grounds even in the construction of pipeline communications. Seismic wave dynamics (amplitudes and spectra) are used rarely in railway roadbed state testing, although it is these wave-field parameters that are most sensitive to deformation properties changes of the geological medium. Our seismic method is passive one (without special sounding sources) based on monitoring of three-component (X, Y, Z) amplitudes of seismic records of passing train vibrations in the low-frequency band (below 0.5 Hz). In our experiment, the broadband seismometers (Trillium Compact 120 s with Centaur datalogger (Nanometrics)) were installed near the railway track on the dangerous and stable sections. We analyzed a set of seismic records from different trains during observation time. We recorded vibration velocity seismograms as the velocity parameter was more

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sensitive to tension increasing then acceleration. Currently, the oscillation velocity is used already in some standards, for example, in the USA when calculating underground pipelines [13], as well as in the American Lifelines Association [14] and in European building codes [15]. Also we used shallow seismic survey including reflection and refraction methods to study the structure of the railway roadbed. The methods are based on the use of different types of seismic waves characterized by different modes of propagation. The common feature of all these methods is their sensitivity to spatial changes of seismic velocities in the subsurface [16]. The set of seismic data acquired at the surface allows to estimate the subsurface velocity distribution and map the corresponding structural features. For this purpose, each method implements its specific acquisition and processing techniques. A short general overview of shallow seismic methods was made by Steeples [17]. Broadband seismic sensors location and the schematic cross section of the roadbed for dangerous and stable areas, obtained by the results of shallow seismic survey, are shown in Fig. 2.

3 Discussion of Results Let us consider the roadbed response to trains vibration impact. Ground oscillations produced by a passing train can be represented as the superposition of two components: a low-frequency one with periods of 100–150 s and a high-frequency component with frequencies of 0.5 Hz or higher (see Fig. 3). The time duration of high-frequency component (HFC) is approximately the half of the low-frequency (LFC) one, because LFC indicates the relaxation of ground after passage of a train. The power spectra (in vibration velocities) for different components and different trains are similar up to a frequency of 10 Hz, whereas at higher frequencies, they show a noise nature. Stable peaks can be seen in the spectra at frequencies of approximately 2 and 5 Hz (Fig. 4); these peaks show the vibration level in the lower part of the track foundation, but peak frequency can drift, apparently due to the train speed. For the frequency band about 2 Hz, across-track vibrations (Y) are the highest one, in order higher in magnitude than those along the track (X) and vertically (Z); at the same time, in a frequency band of 5 Hz or above, the largest vibrations are observed along Z (see Table 1). We noticed that train movement leads to the appearance of a low-frequency roadbed vibration (below 0.5 Hz). It’s a main feature of observed records which is unique for seismograms of transport oscillations and cannot be confused with other technogenic or natural seismic signals. In our opinion, it is this feature should be used to characterize of roadbed state. The vibration amplitude is known to be determined by the elastic properties of soil. The amplitude–temporal change shows its increase when train impact and decrease after impact removal. The parameters of these amplitude–temporal curves are connected with medium viscoelastic properties.

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Fig. 2 Geological and geophysical roadbed crosssection for dangerous a and stable b areas; c– scheme of shallow seismic profiles: 1–shallow seismic profiles, 2–places of broadband seismic sensors installation; 3–railway; 4–ground water level; 5–road metal with sand; 6–loam with boulders (power 4.5 m or more); 7–clay rocks: interlayer of silt and clay (power 20 m or more); 8–age of depositions; 9–P- and S-waves velocities

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Fig. 3 Example of velocity records from train movement by broadband sensor on dangerous railway zone: X, along track; Y, across track; Z, vertical component; a–typical recording (without filter); b–filter 120 s–0.5 Hz; c–filter 0.5–100 Hz. 1 count = 3.34E-09 m/s

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Fig. 4 Power spectra density of different passing trains a and their corresponding spectral time diagrams b: X, along track; Y, across track; Z, vertical component

Table 1 Seismic impact parameters for mathematical modeling of dynamic effect produced by train on the roadbed dangerous section Frequency, Hz

Acceleration amplitudes, mm/s2:

Duration, s

Along roadbed

Across roadbed

Z

2

0.4

3

0.4

100

5

2

5

19

100

6

4

8

30

100

7

5

4

10

100

As we see, the low-frequency vibrations are present in all three components: two horizontal (along and across the roadbed) and one vertical. Bearing the task of continuous monitoring in mind, it is important to find the parameters that characterize the state of roadbed. To this end, the curves of low-frequency vibrations were compared for dangerous and stable sections, for three components, and for different trains. The most representative results are shown in Fig. 5 exhibiting the roadbed motion

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Fig. 5 Curves corresponding to motion trajectories of roadbed point due to train movement in frequency band 120 s–0.5 Hz in horizontal plane. Colored lines indicate different trains. Sensors are installed on different ground types: a–dangerous, b–stable soil

trajectories at low frequencies (120 s–0.5 Hz). Note that the curves are presented at different scales, since the most intense oscillations occur across the roadbed (Y). Comparison of the curves for different roadbed sections shows that the main feature of a dangerous area is the presence of bipolar waveform of vibrations (with positive and negative phases). The same is clearly seen in Fig. 3, where the amplitude change of the low-frequency vibration (downwards for horizontal components and upwards for vertical ones) begins after the end of the high-frequency signal. The noted bipolar features are peculiar to dangerous area. For stable roadbed section, such effect was not obtained. Figure 6a, b shows typical examples of relationship between the high-(>0.5 Hz) and low-frequency (0.5 Hz, blue curves) and low-frequency (130 dB). Experiments show that a bipolar waveform of vibrations (with positive and negative phases) in horizontal plane along and across the railroad bed is an indicator of a troubled state of ground. A virtually unipolar signal is for stable roadbed ground state. Practical monitoring application is that the occurrence of a bipolar low-frequency waveform of the velocity record may be an evidence of deterioration of the ground state in a railroad bed foundation, e.g., due to flooding, ground thawing, etc.

6 Funding Information This study was supported by the Russian Foundation for Basic Research, project no. 17-20-02119 “Development of a Technique for Seismic Monitoring and Rapid Assessment of the State of Railroad Tracks in Conditions of the Far North and Siberia.”

References 1. Decree of the Government of Russian Federation no. 877-r of June 17, 2008. Homepage. http://www.rzd-expo.ru/innovation/regulatory_documents/01Rasporyazhenie877-r.pdf. Last accessed on 01 Oct 2018 2. Konshin GG (2004) Metody i sredstva diagnostiki zemlyanogo polotna: Uchebnoe posobie (Methods and Means of Roadbed Testing: A Textbook). Moscow State University of Railway Engineering, Moscow 3. Lebedev AV (2014) State of railway roadbed state. Evraziya Vesti 7 Homepage. http://www. eav.ru/publ1.php?publid=2014-07a08. Last accessed 01 Oct 2018 4. RZD-Partner Homepage. http://www.rzd-partner.ru/zhd-transport/news/za-period-2009-2016g-pokazatel-defektnosti-zemlyanogo-polotna-vyros-na-54/. Last accessed on 25 Dec 2018

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5. Ashpiz ES, Vavrinyuk TS (2012) Assessment of embankments stability in view of consolidation processes in foundation soil in permafrost. In: Chen F, Bai MZ, Gao L, Bai Y, Shen YP (eds) 2nd international conference on Railway Engineering: New Technologies of Railway Engineering (ICRE2012), China Railway Publishing House p 333 6. Kondratyev VG (2008) The age-old but not eternal problem of railways on permafrost. Transp Russ Fed 3–4(16–17):58–61 7. Megaproekt “Yamal” Homepage. http://www.gazprom.ru/about/production/projects/megayamal. Last accessed on 28 Jan 2018 8. Evaluation Report Homepage. http://www.greenpeace.org/russia/ru/press/reports/4121202/. Last accessed on 28 Jan 2018 9. Case study: earthquake early warning system for the Honam high-speed railway, South Korea. Homepage. https://www.geosig.com/files/CaseStudy_Honam_South%20Korea.pdf. Last accessed on 25 Dec 2018 10. Case study: earthquake early warning system for the TGV high-speed railway, France. Homepage. https://www.geosig.com/files/CaseStudy_TGV_HighSpeedRailway_France.pdf. Last accessed on 25 Dec 2018 11. Qin Y, Zhang J (2013) A review on the cooling effect of duct-ventilated embankments in China. Cold Reg Sci Technol 95:1–10 12. Sadykova RM (2016) Improving of pipelines operation technology with liquefied natural gas and gas condensate in the far north. In Dissertation abstract for Ph.D. student of Technical Sciences. (in Russian) https://docplayer.ru/57220003-Sadykova-rimma-maratovna.html 13. Guideline for the design of buried steel pipe. Homepage. https://www. americanlifelinesalliance.com/pdf/Update061305.pdf. Last accessed on 25 Dec 2018 14. American lifelines association. Seismic fragility formulations for water systems. Homepage. https://www.americanlifelinesalliance.com/Products.htm#WaterSystems. Last accessed on 25 Dec 2018 15. Eurocode 8: Design of structures for earthquake resistance. British Standard. Homepage. http://files.isec.pt/DOCUMENTOS/SERVICOS/BIBLIO/Documentos%20de%20acesso% 20remoto/Eurocode-8-1-Earthquakes-general.pdf. Last accessed on 25 Dec 2018 16. Shtivelman V (2003) Application of shallow seismic methods to engineering, environmental and groundwater investigations. Bollettino di Geofisica Teorica ed Applicata 44(3–4):209–222 17. Steeples DW (2000) A review of shallow seismic methods. Ann Geofis 43:1021–1044 18. Murao O, Tanaka H, Yamazaki F (2000) Risk evaluation method of building collapse from the experience of the Kobe earthquake. In Proceeding 12 WCEE, Twelfth World Conference on Earthquake Engineering, paper № 2312. Auckland, New Zealand) 19. Dolgaya AA, Indeykin AB (2002) Statistical analysis of Arias’s intensity and velocity for real earthquakes. Antiseismic constr 2:32–33 20. Akkar S, Ozen O (2005) Effect of peak ground velocity on deformation demands for SDOF systems. Earthq Eng Struct Dyn 34(13):1551–1571 21. Sakurai T, Shoji G, Takashashi K, Nakamura T (2012) Damage assessment road structures due to pacific coast of Tohoku earthquake. In Proceedings of the international symposium on Engineering Lessons Learned from the 2011 Great East Japan Earthquake, pp 961–972. Tokyo, Japan 22. Yang DX, Wang W (2012) Nonlocal period parameters of frequency content characterization for near fault ground motions. Earthq Eng Struct Dynam 41(13):1793–1811 23. Ghayoomi M, Dashti S (2015) Effect of ground motion characteristics on seismic soil– foundation–structure interaction. Earthq Spectra 31(3):1789–1812. https://doi.org/10.1193/ 040413EQS089M 24. Khmelevskoy VK, Zaderigolova MM (2016) Radiowave and gas-emanation control of objects in the fuel and energy sector in the zones of natural and anthropogenic risks. Mosc Univ Geol Bull 71(4):300–303. https://doi.org/10.3103/S0145875216040049

Analysis of Vibration Measurements on Moving Trains Jonas Majala

and Jan Laue

Abstract The development in society means that infrastructure like ballasted railway systems is facing challenges due to requests for a increased number of high-speed trains and heavier freight trains. This implies that ballasted railways get an increased impact from larger dynamic loads. The question is how the ballasted railways are today affected by dynamic loading and how will an increase in train speed and weight change the soil behavior within the railway embankment. A method of investigating soil behavior is via geophysical measurements. Accelerometers are commonly used for vibration measurements and by installing them on trains, measurements are possible to perform for complete railway sections. The knowledge of Eigen frequencies for various track components and soil layers are essential when considering frequency analysis of accelerometer measurements. Specifically, this means that the analysis is about detecting resonance of different components. From the actual case study, a good correlation is obtained between the expected Eigen frequencies and the measurement results. Thus, an assessment of the dynamic loadings influences on various soil layers and ballast has been possible to perform. Resonance of a soil layer means that the particles will be rearranged and degraded. For the case when saturated soil layers are subjected to resonance a phenomenon called liquefaction can occur if the pore pressures increases to the level were soil layers lose their effective stresses. Therefore, the most critical finding in this study is liquefaction because it leads to a loss in bearing capacity followed by settlements. Old railway tracks where little or no information exists of the soil conditions are the most suitable areas were this measurement and analysis method is of special use. Consequently, conventional borehole sampling can be reduced. Keywords Dynamic load · Frequency · Railway

J. Majala (B) · J. Laue Luleå University of Technology, 97187 Luleå, Sweden e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_14

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1 Introduction Ground-borne vibrations are generated by dynamic loads which induce energy into the soil and cause wave propagation in the ground [1, 2]. Since moving trains cause dynamic loading there is a phenomenon within the railway infrastructure which can be associated to dynamic loading such as liquefaction, rearrangement and degradation of material leading to settlements [3, 4]. By investigations of the previously conducted research in the field of train-induced ground vibrations, the focus is mainly on prediction models of ground vibrations in the vicinity of the railway having the prediction of wave velocity as the central subject as well as displacements due to soil/structure response [5, 6]. Thus, measurements of vibrations on moving trains together with an analysis method focusing on the frequency content where soil layer Eigen frequencies have a central role, more knowledge can be obtained about how the effect of dynamic loads from trains is. Since settlements could be reduced by detecting the soil resonance along railways and therefore know where measures must be taken for specific soil layers. Nevertheless soil layer thicknesses are possible to determine along railways by back calculations integrated with Eigen frequency analysis. Hence, this measurement and analysis method can be considered as crucial for investigations of old railway sections where little information exist about the soil stratigraphy.

2 Assumptions Dynamic loading has become more of a priority subject for the Swedish Transport Administration, however, and the assessment of track condition is performed based on measuring the height and side positions of the rail profile. So-called measuring trains conduct these measurements and to obtain the change in height and side position, accelerometer data from the time domain is processed in order to get metric displacements. Instead of processing the acceleration data into metric displacements, it can be transferred by Fourier transformation into a frequency domain which enables a dynamic response analysis of the railway superstructure and subgrade. Single-degree-of-freedom model is the basis for soil dynamics. Thus, Eigen frequency becomes the most important parameter to consider in dynamic analysis. By determination of all track component Eigen frequencies, the essential information is obtained for further analysis where the aim is to assess in which magnitude track components are affected by dynamic loading. This can be discovered by detection of resonance frequencies that are visible as amplitude peaks for certain frequencies. Interpretation of dynamic analysis enables two possible approaches. First one is determination of the impact on soil, because negative consequences such as settlements are declared by many researchers. Second one is related to determination of soil layer thicknesses for railway sections by using the relationship between layer thickness, Eigen frequency and shear wave velocity in a back-calculation approach.

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3 Method Data used for frequency analysis of train-induced vibrations is possible to acquire in various ways. On moving trains, accelerometers are possible to use for data acquisition of train-induced vibrations which is the case for measurement trains. Another method is to have accelerometers mounted on the crossties or within the railway embankment. Through this, the local data of train-induced vibrations caused by the passing train are obtained and changes in the frequency content might be detected during passing of the train. This will also offer the opportunity to identify changes in the soil behavior over the length of the train and will provide further information about increase in pore pressures and a potential onset of pumping or liquefaction after a certain amount of wheel axle passages. Frequency analysis requires data in a frequency domain which implies that the acquired vibration data in time domain has to be transformed. This transformation is possible to perform with means of a programing language and Fast Fourier Transformation (FFT) code. When the transformation is performed, the frequency analysis can be conducted by detection of amplitude peaks which are related to the sought Eigen frequencies. Thus, an assessment is feasible to perform of which soil layers and track components are affected by resonance. Measurement data for the study considered in this paper is retrieved from measurement trains. Two railway sections between Boden and Gällivare in northern Sweden are selected for the frequency analysis. First section is Tolikberget and second one is Polcirkeln–Koskivaara, since these are located in the northern part where freezing and thawing of the soil occurs, data is obtained both from May to October. In other words from the season with thawing and freezing, respectively. Thus, a comparison between soil behavior is possible when thawing occurs and freezing begins. Through Swedish Transport Administration, the technical requirements for analytical calculations of dynamic soil properties and information of soil conditions are obtained. Thus, Eigen frequencies of ballast and subgrade can be calculated.

4 Results 4.1 Railway Section Tolikberget Section km 1222 + 300-1222 + 400 between Boden and Gällivare which is a 100 m long part along Tolikberget is the location for the first study. The information of soil conditions is obtained from Swedish Transport Administrations geotechnical database [7], where the superstructure consists of 0.5 m thick ballast layer and the subgrade of 2.0 m thick gravely silty sand layer (see Fig. 1).

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Fig. 1 Soil stratigraphy of railway embankment at Tolikberget [7]

Eigen frequencies of the soil layers are 26.46 Hz and 119.80 Hz for the subgrade and ballast, respectively [8]. All calculations are based on the requirements of Swedish Transport Administration [9]. Since the speed of a train can affect the magnitude of ground-borne vibrations. Thus, calculation of the train average speed during the measurements in May and October must be considered. However, calculations show minor differences. Thus, the impact of train speed is not considered to affect the variations in the results [8]. Results of the transformed data based on data from measurements performed in May and October are presented below (see Figs. 2 and 3). The frequency domain of the graphs is within the range of subgrade Eigen frequencies 0–100 Hz. Since the vibrations are measured on both left and right hand side of the train are the results shown for both sides (Table 1).

Fig. 2 Results of transformed data, frequency range 0–100 Hz, Tolikberget km 1222+300– 1222+400 May 2016 [8]

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Fig. 3 Results of transformed data, frequency range 0–100 Hz, Tolikberget km 1222+300– 1222+400 October 2016 [8]

Table 1 Eigen frequencies for subgrade and ballast Soil type Subgrade Ballast

Expected Eigen frequencies (Hz)

Eigen frequencies from measurements (Hz)

26.46

24

119.80

120

4.2 Railway Section Polcirkeln–Koskivaara The second studied section with a length of 100 m is km 1251+200–1251+300 between Boden and Gällivare located at Polcirkeln–Koskivaara area. Information about the soil condition for this section is obtained through the geotechnical database from Swedish Transport Administration [7]. The superstructure has a ballast layer with varying thickness between 0.5 and 1.5 m. Since Polcirkeln–Koskivaara is a swamp area, the subgrade consists mainly of peat with a layer thickness varying between 0.7 and 5.5 m (see Fig. 4). Eigen frequencies of the ballast and peat layers are calculated to be within a range due to the varying layer thicknesses. The peat layer has an Eigen frequency in the range of 6.8–67.6 Hz and the ballast layer Eigen frequency varies between 44.5 and 101.3 Hz [8]. These calculations are also based on the requirements from Swedish Transport Administration [9]. Significant difference in percentage is found regarding the average speed of the measurement train, in October is the average speed 41% higher than in May [8]. Results regarding the transformed data based on measurement data from May to October are presented for both left and right hand side of the train (see Figs. 5 and 6).The range of the frequency domain is within the subgrade and ballast Eigen frequency 0–100 Hz (Table 2).

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Fig. 4 Soil stratigraphy of railway embankment at Polcirkeln–Koskivaara [7]

Fig. 5 Results of transformed data, frequency range 0–100 Hz, Polcirkeln–Koskivaara km 1251+200–1251+300 May 2016 [8]

5 Analysis To have knowledge about the weather conditions for the time period in May and October are of importance since it provides information regarding possible saturation degree of the soil and amount of frozen soil. Swedish Transport Administration film database contains videos from the measurements and therefore the actual weather conditions during each measurement are possible to assess. Considering both Tolikberget and Polcirkeln–Koskivaara during the thawing period in May, no

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Fig. 6 Results of transformed data, frequency range 0–100 Hz, Polcirkeln–Koskivaara km 1251 200–1251+300 October 2016 [8]

Table 2 Eigen frequencies for subgrade and ballast Soil type Subgrade Ballast

Expected Eigen frequencies (Hz)

Eigen frequencies from measurements (Hz)

6.8–67.6

18–67

44.5–101.3

45–101

covering snow layer is visible. Nevertheless, the subgrade and ballast might contain more water because of partly frozen areas within the different soil layers which in other hand can affect the soil behavior. Thus, a deviation from dry conditions can take place in obtained measurement data. Therefore, an analysis with respect to dry soil conditions must be considered of importance for confirmation of the dynamic soil behavior without an impact of excess pore water. Hence, analysis is conducted related to the beginning of the freezing period which occurs in October.

5.1 Frequency Analysis of Measurements from Railway Section Tolikberget Analysis of Measurements Performed in May. Superstructure and subgrade resonance frequencies are mainly associated with a low-frequency range between 0 and 100 Hz. Through the results resonance is detected at 24 Hz, since the subgrade Eigen frequency is estimated to 26 Hz it is very likely related to the subgrade. At 35 Hz a resonance peak is detected which is possible to associate with the subgrade because according to an empirical chart over Eigen frequency versus layer thickness for various soil types [3] the subgrade Eigen frequency can obtain a value of 35 Hz. Resonance is detected as well at 47 Hz, according to Lichtberger [3] is the Eigen frequency of a superstructure between 44 and 49 Hz depending on the type of crosstie. Thus, this can be related to resonance of the superstructure.

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Analysis of Measurements Performed in October. Comparing the results from May with these in October indicates minor differences. The only significant difference is that the higher resonance frequency peak at 24 Hz is detected at the right rail in October measurements instead of the left rail as in May month’s measurements. There are two possible explanations for this difference, first one is related to effects of thawing which causes softer soil conditions and more damping. The other explanation is that during October, the measurements are conducted in opposite direction compared with May. Analysis of the Resonance Impact. Liquefaction is a phenomenon related to a consequence of saturated coarse-grained soil being affected by resonance [4]. Therefore, it is of importance to consider for a railway section such as Tolikberget which has a subgrade consisting of gravely silty sand and a ground water table following the subgrades surface [10]. The consequence due to liquefaction is bearing capacity loss by low effective stresses leading to settlements. However, with very high pore pressures water can be transported through the ballast layer and cause liquefaction in that layer as well. Rearrangement of soil particles occurs in cohesionless soils during resonance and increased number of load cycles. Thus, permanent vertical strains increase regardless of saturation level hence the effect of resonance must be taken into account [4]. Initially ballast material is of a square and angular shape. However, dynamic loading causes a deterioration of the grains with time. Thus, rounder grains will form decreasing the dilatancy angle resulting in material compaction. In addition, finegrained material is formed between the larger particles causing degradation of the shear strength, shear modulus and bearing capacity of the material [3].

5.2 Frequency Analysis of Measurements from Railway Section Polcirkeln–Koskivaara Analysis of Measurements Performed in May. Analytical calculations of subgrade and ballast Eigen frequencies indicates variations in the values. However, resonance frequencies are only detected between 40–45 Hz and 50–57 Hz which is not fully according to expected values of resonance frequencies along this section. Resonance frequencies related to subgrade and ballast are expected to be in a range 6.8–67.6 Hz and 44.5–101.3 Hz, respectively. In the absence of lower and higher resonance frequencies, suspicions arise that something is not as it should be when the opposite is discovered in measurements from October. Thus, resonance frequencies between 40–45 Hz and 50–57 Hz which are as well detected in October can be related to resonance of superstructure and ballast according to performed calculations [8] and values obtained from literature [3]. Explanation for the absence of lower and higher resonance frequencies is either due to the lower speed of the train or that the soil has been partly frozen during the time of measurements since according to Swedish Transport Administration [11] a 1-m thick ice layer was detected in this area during

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May 2016. If the latter is the case resonance of peat is shifted to very high frequencies, since ice can obtain a shear wave velocity value of 1950 m/s [12] which implies that the Eigen frequency is shifted near 975 Hz [8]. Analysis of Measurements Performed in October. Resonance is detected for the subgrade and ballast within the expected frequency ranges. Thus, two parts are confirmed, first is that resonance detected in measurements from May is related to superstructure and ballast. Second part is that resonance detected in the lower and higher range is related to the subgrade and ballast, since correlation between analytical calculations and measurement results is obtained. Analysis of the Resonance Impact. Soil investigations show that the subgrade of peat has high water content [13], thus the peat can be considered to be in a liquid state. However, pore pressure increases due to resonance and dynamic loading must be considered [4], since the water can be transported through the ballast layer and cause liquefaction within it. Earlier description regarding resonance impact on ballast implies for this section as well, thus material deterioration occurs followed by an increase of fine-grained material between larger particles causing degradation of shear modulus, shear strength and bearing capacity which leads to settlements [3].

6 Conclusions Correlation is obtained between analytically calculated Eigen frequencies and measurement results showing resonance frequencies. Thus, it is possible to detect with this method which soil layers and track components are affected by resonance. Hence, this method can be considered reliable. Consequences due to resonance of soil layers are important to consider and the consequences in return change the resonance frequency. Phenomenon such as liquefaction or pumping due to an increase in pore water pressure over time, rearrangement of soil particles and deterioration of ballast can occur. Liquefaction occurs due to increased pore pressures within a saturated soil until the effective stresses are absent resulting in bearing capacity losses and settlements [4]. Regardless of saturation level in coarse-grained soils, rearrangement of soil particles occurs due to resonance and increased number of load cycles, thus permanent vertical strains increase [4]. Deterioration of ballast material cause fine-grained material to be formed between larger particles leading to degradation of the shear strength, shear modulus and bearing capacity of the material [3]. By changing the thickness, density or the effective stresses of a layer, the layers Eigen frequency can be changed. Thus, the resonance amplitude of various layers can be reduced. The implementations of this method are to detect the magnitude of different soil layers resonance and to be able to assess the thickness of soil layers by means of back calculations between two known positions where data of the soil conditions are available. Suitable areas were this measurement and analysis method is of particular

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use are old railway tracks where little or no information exists of the soil conditions. Thus, conventional borehole sampling can be reduced. Acknowledgements The authors would like to acknowledge thank to Swedish Transport Administration in their research and development program Branschsamverkan i Grunden (BIG) and Luleå University of Technology for the given resources and support associated to this research.

References 1. Chouw N, Le R, Schmid G (1991) Propagation of vibration in a soil layer over bedrock. Eng Anal Bound Elem 8(3):125–131 2. Hall L (2003) Simulations and analyses of train-induced ground vibrations in finite element models. Soil Dyn Earthq Eng 23(5):403–413 3. Lichtberger B (2005) Track compendium, eurailpress, 1st edn. Tetzlaff-Hestra GmbH Co., Hamburg, Germany 4. Richart F, Woods R (1970) Vibrations of soils and foundations. Prentice-Hall, New Jersey, USA 5. Kouroussis G, Verlinden O, Conti C (2010) On the interest of integrating vehicle dynamics for the ground propagation of vibrations: the case of urban railway traffic. Veh Syst Dyn 48(12):1553–1571 6. Picoux B, Rotinat R, Regoin J, Le Houédec D (2003) Prediction and measurements of vibrations from a railway track lying on a peaty ground. J Sound Vib 267(3):575–589 7. Trafikverket Geoteknisk Databas. http://ppikarta4.trafikverket.se/GeoArkivMap.aspx?MapId= a28ebb04-17b7-4f31-b938-9077f421a179&export=1. Last accessed 19 Apr 2017 8. Majala J (2017) Frequency analysis of accelerometer measurements on trains. Master’s Thesis, Luleå University of Technology, Luleå, Sweden 9. Trafikverket TK Geo 11, Trafikverkets tekniska krav för geokonstruktioner. https://trafikverket. ineko.se/Files/sv-SE/10749/RelatedFiles/2011_047_tk_geo_11_2.pdf. Last accessed 26 Apr 2017 10. Noppa J (2003) PM Geoteknik, Bandel 118, Boden-Gällivare, Bansträcka: Näsberget-Murjek. Ny Mötestation vid Tolikberget. Banverket Projektering, Sweden 11. Eriksson E-G (2017) Trafikverket, Personal Contact. Trafikverket 2017/5/23 12. Kohnen H (1974) The temperature dependence of seismic waves in ice. J Glaciol 13(67):144– 147 13. Gustafsson S, Engström T, Finnberg Ö (2016) Förstärkningsåtgärder km 1250+980–1251+400, Bandel 118 Polcirkeln-Koskivaara. MUR-GEOTEKNIK. Trafikverket Investering Nord, Sweden

Geoecological Aspects of 27 Tons Axle Load Innovative Cars Influence on the Railway Roadbed Ivan Kozlov , Ksenia Ivanova , Dmitry Kozlov , Vadim Govorov and Evgenii Shekhtman

Abstract This article presents the results of studies conducted in the cold region of Russia (Sverdlovsk Region, near Nizhny Tagil). Railway embankments operate in freezing and thawing conditions Therefore, the data obtained are of interest to the conference «Transoilcold2019». The purpose of the research is to conduct vibration diagnostics of the embankments under the influence of train load from cars with an axle load of 27 tons in comparison with cars with an axle load of 23.5 tons with a forecast of changing their condition by the stability criterion. Field measurements and analysis of vibration effects are applied. The determination of the vibration velocities of the oscillations indicates that in all experiments, the resulting amplitudes of the vibration velocities of the oscillations on the edge and the slope of the roadbed at a distance of 5–7 m from the edge at speeds of 30–70 km/h both for conventional trains and for innovative ones did not exceed 2.0 mm/s. Thus, in the experiments conducted in the period November–December 2017, there was no fixed change in the level of the oscillations at the level of the edge and the slope of high embankments in all experimental sections when the innovative rolling stock moved with cars having an axle load of 27 tons. The surveyed embankments when moving both ordinary trains and trains formed from cars with a load of 27 tons are classified as stable. Thus, when applying to experimental sections of innovative cars, there is no change in the state of high embankments by the stability criterion. All embankments are characterized as stable. The obtained results can be used to develop the norms for the device, operation, maintenance and diagnostics of the track infrastructure for the trains with an axle load of 27 tons. The article also contains the geoecological aspects. Keywords Vibration diagnostics · Innovative train · Axle load · Embankment · Vibration velocity · Amplitude of oscillations · Roadbed

I. Kozlov (B) · K. Ivanova · D. Kozlov · V. Govorov · E. Shekhtman Emperor Alexander I State Transport University, St. Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_15

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1 Introduction Most of Russia’s territory is located in cold regions. Railway roadbed works in difficult conditions [1–3]. It freezes and thaws. The design becomes more rigid during freezing. This leads to a decrease in the intensity of vibration damping. When thawing, the strength characteristics of the soil of the roadbed deteriorate [4–6]. The stability of the roadbed is reduced [7–9]. Domestic [10–13] and foreign [14–18] scientists have conducted many studies of the vibration of the railway roadbed, depending on different factors. Including at the increased axle loads [2, 5, 7, 19, 20]. However, this article contains new data of vibrodiagnostics, as the increased axle load is transmitted from innovative cars with a lower coefficient of dynamics. Vibration diagnostics of embankments is carried out in order to assess the change in their state (possible transition to a relatively unstable or unstable state) when putting into circulation on experimental sections of trains formed from innovative cars with increased axle load [1, 21], in this case 27 tons. Tests were carried out at each experimental site: – site 1 at 346 km picket (PK) 8 Laya-San-Donato trains directions Perm–Yekaterinburg; – site 2 for 340 km of the PK 6 Baranchinskaya—Laya routes, Perm–Yekaterinburg; – site 3 at 327 km of the PK 7 of the Baranchinskaya—Laya route, Perm–Yekaterinburg. In general, it should be noted that all three sections are characterized by a stable state of the track gauge according to the passages of the track car, do not refer to the distance data of the path to the diseased parts of the roadbed. When testing with the movement of conventional and innovative trains, an assessment was made of the stability of both the left and right slopes of the embankments. In this case, in assessing the stability of the slope from the side of the main link path II, both in the rail joint zone and in the middle part of the link are performed.

2 Test Method Testing, statistical processing, and calculation of diagnostic parameters were carried out in accordance with the «Instruction…» approved by the decree of Russian Railways № 2561p of October 29, 2014 [21]. The seismic receivers during the experiments were installed on the edge of the roadbed and on the slope of the embankment at a distance of 5–7 m from the edge, which made it possible to record the effective amplitudes of vibration velocities at each sensor installation point: on the edge of the roadbed V 1 (in mm/s), on the slope V 2 (in mm/s), as well as attenuation coefficients along the slope β (in 1/m) and the intensity of oscillations in the frequency band of the frequency range 0.1–10 Hz (I, %).

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At each parking lot of the geophones, three sensors were included in the kit, allowing the recording of vibration velocities in three mutually perpendicular directions: in the vertical plane, in the longitudinal, and transverse axis of the track direction.

3 Results and Discussion Tables 1, 2, and 3 summarizes the results of the amplitude values of the vibration velocity of the oscillations recorded in all experimental sections as during the movement of conventional graphical trains consisting of cars with axle loads up to 23.5 tons and trains formed from innovative carriages with axle load 27 tons. The results of the tests (see Tables 1, 2 and 3) indicate that in all experiments, the resulting amplitudes of vibration velocities of oscillations at the edge and slope of the roadbed at a distance of 5–7 m from the edge at speeds of 30–70 km/h for trains, both conventional and innovative, did not exceed 2.0 mm/s. The range of their variation was for conventional trains 0.47–1.67 mm/s on the edge of the roadbed and 0.27–1.25 mm/s on the slope of the embankment. With the movement of innovative trains, this range of changes in the amplitude of the vibration velocities was 0.32–1.79 Table 1 Actual amplitudes of the full vector of the vibration velocity of oscillations in the soil of the subgrade in the area № 1—346 km PK 8 of the Laya-San-Donato section of the Perm–Yekaterinburg Type of rolling stock

Location of seismic receivers

Effective amplitudes of the full and vector vibration velocity of oscillations, Vi , mm/s From the side of the I main track at the speed of movement, km/h

From the side of the II main path in the middle of the link at a distance 12 m from the joint zone, km/h

From the side of the II main track in the rail junction area, km/h

40–50

60–70

40–50

60–70

40–50

60–70

Normal Pax = 23.5 T

On edge

0.67

–

1.63

–

–

1.62

On slope

0.46

–

1.07

–

–

1.16

Innovative Pax = 27.0 T

On edge

0.48

–

1.16

–

–

1.63

On slope

0.38

–

1.02

–

–

1.08

The difference when moving two types of trains, %

On edge

−28

–

−29

–

–

1

On slope

−17

–

−5

–

–

−7

The attenuation coefficient of the resulting oscillations along the slope, β, m−1

Pax = 23.5 T

0.06

–

0.07

–

–

0.06

Pax = 27.0 T

0.04

–

0.02

–

–

0.07

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Table 2 Actual amplitudes of the full vector of the vibration velocity of oscillations in the soil of the subgrade in the area № 2—340 km PK 6 of the Baranchinskaya—Laya section of the Perm– Yekaterinburg Type of rolling stock

Location of seismic receivers

Effective amplitudes of the full and vector vibration velocity of oscillations, Vi , mm/s From the side of the I main track at the speed of movement, km/h

From the side of the II main path in the middle of the link at a distance 12 m from the joint zone, km/h

From the side of the II main track in the rail junction area, km/h

50–60

60–70

50–60

60–70

50–60

60–70

Normal Pax = 23.5 T

On edge

–

0.47

1.33

–

1,48

–

On slope

–

0.27

0.75

–

1,25

–

Innovative Pax = 27.0 T

On edge

–

0.38

1.03

–

1.79

–

On slope

–

0.22

0.82

–

0.99

–

The difference when moving two types of trains, %

On edge

–

−19

−23

–

21

–

On slope

–

−19

9

–

−21

–

The attenuation coefficient of the resulting oscillations along the slope, β, m−1

Pax = 23.5 T

–

0.09

0.10

–

0.03

–

Pax = 27.0 T

–

0.09

0.04

–

0.10

–

and 0.22–1.08 mm/s, respectively. Thus, in experiments conducted in November– December 2017, there was no fixed change in the level of oscillations at the level of the edge and the slope of high embankments in all experimental areas when moving the innovative rolling stock with cars having an axle load of 27 tons. At the same time, in a comparative analysis of the results obtained, a slightly lower level of vibration velocity amplitudes was detected both on the edge and on the slope of the embankment during the movement of innovative trains along the unshackled track and along the link path outside the rail joint zone (Table 4). On average, the reduction in the maximum probable resultant amplitudes of vibration velocities at the level of the roadbed was 19%, and at a distance of 5–7 m from the edge on the sloping part of the embankment—11%. In the zone of the rail joint, a decrease in the level of oscillations at the level of the edge of the roadbed was not recorded in the experiments. On average, in this case, an insignificant increase in the amplitude of the vibration velocities is observed at the level of 7%. At the same time, such a difference in the results obtained is more a statistical error of the experiment, so it should be noted that the amplitude of the vibration velocities is practically the same at the level of the edge of the roadbed in the area of

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Table 3 Actual amplitudes of the full vector of the vibration velocity of oscillations in the soil of the subgrade in the area № 3—327 km PK 7 of the Baranchinskaya—Laya section of the Perm– Yekaterinburg Type of rolling stock

Location of seismic receivers

Effective amplitudes of the full and vector vibration velocity of oscillations, mm/s From the side of the I main track at the speed of movement, km/h

From the side of the II main path in the middle of the link at a distance 12 m from the joint zone, km/h

From the side of the II main track in the rail junction area, km/h

30–40

50–60

30–40

50–60

30–40

50–60 –

Normal Pax = 23.5 T

On edge

–

0.60

–

0.97

0.67

On slope

–

0.47

–

0.61

0.35

–

Innovative Pax = 27.0 T

On edge

0.32

–

0.55

1.05

0.67

–

On slope

0.29

–

0.41

0.52

0.25

–

The difference when moving two types of trains, %

On edge

–

–

–

8

0

–

On slope

–

–

–

−15

−29

–

The attenuation coefficient of the resulting oscillations along the slope, β, m−1

Pax = 23.5 T

–

0.04

–

0.08

0.11

–

Pax = 27.0 T

0.02

–

0.05

0.12

0.16

–

Table 4 The average change in the amplitudes of vibration velocity during the movement of conventional and innovative rolling stock Measuring point

The difference in amplitudes of vibration velocity,%, compared to conventional graphic trains in the speed range 30–70 km/h From the slope of I main path, the middle part of the length

From the II main path, the middle part of the course

From the II main path, rail junction is

On edge of embankment

−24

−15

7

On the slope at distance 5–7 m from edge

−18

−4

−19

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the rail joint during the movement of conventional cars with an axle load of 23.5 tons and during the movement of innovative cars with an axle load of 27 tons. These results are in good agreement with the data of the experiments performed in determining the amplitude of the vibrational displacement amplitudes at the main site of the earth sheet. The analysis of the attenuation coefficient of the resulting oscillations along the length of the slope (see Tables 1, 2 and 3) allows us to state that this coefficient has practically not changed quantitatively during the movement of both conventional rolling stock and innovative rolling stock. The difference in the values obtained is due to the statistical error of the experiments. The attenuation coefficient of oscillations along the slope of the embankment in the tests varied from 0.02 to 0.16 m−1 , depending on the area of the experiment and the speed of movement, and its average value was 0.12 m−1 . It should be noted that the attenuation coefficient of the oscillations obtained, as a rule, is characteristic of relatively stable mounds. At the same time, engineering and geological conditions indicate the presence in the base of the roadbed of wetlands of clayey soils having a soft–plastic consistency, which causes less intensive attenuation of vibrations along the slope of the embankments. This fact was repeatedly confirmed in the experiments of LIIZhT-PGUPS in the study of the vibrational process of embankments on weak bases. With an insignificant coefficient of attenuation of the resulting amplitudes of the vibration velocities of the oscillations, the overall level of the vibrodynamic effect in all three experimental sections during the movement of all types of trains both on the edge and on the slope of the embankment did not exceed 2.0 mm/s. According to clause 6.5 “Instructions…” [21], the criteria for the coefficient of damping of oscillations and the intensity of oscillations in the frequency band 0.1–10 Hz are not taken into account when assessing the state of high embankments. In accordance with Table 6.1 “Instructions …” [21], investigated embankments when moving both ordinary trains and trains formed from cars with an axle load of 27 tons are classified as stable both from the side I of the main path and from the side of the main path II. Thus, when the experimental sites of innovative cars were used, there was no change in the state of high embankments by the stability criterion. All embankments are characterized as stable. In practice, there are cases when, based on the results of vibrodiagnostics, a high embankment is not sufficiently stable. Then it should be tested for stability. As a rule, the stability coefficient is obtained more than one, but less than the required standard value. This means that the structure does not have the necessary margin of safety. As the design experience shows, the simplest and most reliable measure to improve sustainability is the dumping of the side loading berms at the base of the roadbed with the setting of the upper part of the slopes of the high embankment. However, this requires sufficiently large amounts of uncontaminated imported soil. In addition, during the reconstruction of the railway under increased axle loads in accordance with the standards of design and construction, it is necessary to create a protective layer of alkaline earth metals to strengthen the main site of the subgrade. Part of the subgrade soil is replaced by a protective layer. Thus, in order to save

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natural resources, as well as to solve the problem of disposal of contaminated soils removed from the main roadbed, it is proposed to lay them in the side loading berms and reposition them with slopes, while neutralizing the use of mineral geoantidote, for example, required to irrigate layers of compacted soil.

4 Conclusions Determination of the vibration velocities of the oscillations indicates that in all experiments the resulting amplitudes of the vibration velocities of the oscillations at the edge and the slope of the roadbed at a distance of 5–7 m from the edge at speeds of 30–70 km/h both for conventional trains and for innovative ones did not exceed 2.0 mm/s. Thus, in the experiments conducted in the period November–December 2017, there was no fixed change in the level of the oscillations at the level of the edge and the slope of high embankments in all experimental areas when the innovative rolling stock moved with cars having an axle load of 27 tons. In winter, the soil of the subgrade, lying below the freezing depth and, accordingly, being in the unfrozen state, there is no additional vibrodynamic effect during the movement of innovative cars with axle load of 27 tons. Consequently, there will be no further reduction in the strength and deformation properties of these soils. Thus, in the winter period of time, it is not expected to reduce the bearing capacity of the main landfill site and the bearing capacity of the embankment base, nor is the decrease in the stability of slopes predicted. The physical and mechanical properties of the soils of the subgrade and its base, as well as the parameters of the vibrating effect on the roadbed, will be further investigated during the thawing period in the second stage of the work in accordance with the schedule. In response to the results obtained, estimates will be made of changes in the reserves of bearing capacity and stability of slopes of the roadbed during the thawing period when innovative cars with an axle load of 27 tons are used. In accordance with the “Instruction …” [21], the investigated embankments during the movement of trains, both conventional and formed from cars with a load of 27 tons per axle, are classified as stable. Thus, when applying to experimental sites of innovative cars, there is no change in the state of high embankments by the stability criterion. All embankments are characterized as stable. Proposal for the use of soil removed from the main site of the roadbed in the construction of a protective layer, in the construction of load berms and in the slope of the upper part of the embankment with simultaneous decontamination of the soil provides geoecological compatibility of the recommended solutions.

References 1. Instruction on the organization of circulation of freight trains of increased mass and length on the railway tracks of the general use of JSC “Russian Railways”. Approved. By order of JSC «Russian Railways» № 1704p of 28.08.2012

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2. Problems of the maintenance of a way at high axle loadings. Railways of the world № 2 pp 66–70 (2005) 3. Prokudin IV (1982) Strength and deformability of a railway roadbed from clay soils that perceive a vibrodynamic load: diss. … doct. tech. sciences, specialty: 05.22.06, 455p. Leningrad: LIIZhT 4. Vinogradov VV (1991) Forecasting and ensuring reliable operation of railway embankments: diss. … doctor of technical sciences, specialty: 05.22.06, 398p. Moscow: MIIT 5. Blazhko LS (2003) The feasibility study of reinforcing the track design on the rolling stock areas with axle loads up to 300 kN: diss. … doct. tech. sciences, specialty: 05.22.06, 331p. St. Petersburg: PSTU 6. Berestyany YuB (1990) Strength of high railway embankments from clay soils under the influence of trains with increased axle and linear loads in conditions of the Far Eastern Railway: diss. … cand. tech. sciences, specialty: 05.22.06, 232p. Leningrad: LIIZhT 7. Lapidus TA (1990) Effect of increased axle. Path Track Econ 2:13–14 8. Blazhko LS (2002) Geomaterials at high axle loads. Path Track Econ 10:36–37 9. Stoyanovich GM (2002) Strength and deformation of the railway roadbed with increased vibrodynamic load in the elastoplastic stage of soil operation: diss. … doct. tech. sciences, specialty: 05.22.06, 360p. Khabarovsk: FENU 10. Konshin GG (2012) Work of the roadbed under the trains. Teaching method. Center for Education at the Railroad Transport, 208p. Moscow 11. Zarubina LP (1970) The study of the influence of dynamic loads on the strength properties of clay soils of the roadbed: diss. … cand. tech. sciences, specialty: 05.22.06, 169p. Leningrad: LIIZhT 12. Kistanov AI (1968) Investigation of the vibrodynamic effect of trains on clay soils of an roadbed: diss. … cand. tech. sciences, specialty: 05.22.06 / A.I. Kistanov. – Leningrad: LIIZhT, 170p 13. Konshin GG (2004) Methods and means of diagnostics of the road bed. Proc. Allowance, 213p. Moscow: Teaching Method. Center for Education at the Railroad Transport 14. Mishra D, Qian Y, Huang H, Tutumlue E (2014) An integrated approach to dynamic analysis of railroad track transitions behavior. Transp Geotech 1:188–200 15. Bei S (2005) Effects of railroad track structural components and subgrade on damping and dissipation of train induced vibration. Doctoral Dissertations, University of Kentucky. p 312 16. Kaewunruen S, Remennikov AM (2008) Dynamic properties of railway track and its components: a state-of-the-art review. In: Weiss BN (ed) New research on acoustics. Hauppauge, Nova Science Publishers, New York, pp 197–220 17. Thompson DJ, Jiang J, Toward MGR (2015) Mitigation of railway-induced vibration by using subgrade stiffening. Soil Dyn Earthq Eng 79:89–103, Part A, December 2015 18. Sunaga M, Sekine E, Takayuki I (1990) Vibration behaviors of roadbed on soft grounds under train load. Q Rep Railw Tech Res Inst, Tetsud¯o Gijutsu Kenky¯ujo 31(1): 29–35. (Japan) 19. Stoynovich GM (2005) In situ study of the dynamic vibration magnitude of the impact of a moving load on the ground. Khabarovsk 20. Petriaev A (2016) The vibration impact of heavy freight train on the roadbed. In: Proceedia engineering, advances in Transportation Geotechnics 3, the 3rd international conference on transportation geotechnics (ICTG 2016), 2016.143, pp 1136–1143. https://doi.org/10.1016/j. proeng.2016.06.110 21. Instructions for conducting vibration diagnostics of high embankments on the railways of JSC «Russian Railways». Approved by the order of Russian Railways № 2561p of October 29, 2014

Estimation of Shear Strength and Shear Wave Velocity for Frozen Soils with Various Silt Fractions Sang Yeob Kim

and Jong-Sub Lee

Abstract Evaluation of the fine particle effect on frozen soils is important since natural deposits in cold regions comprise particles of various size. The goal of this study is to evaluate the strength and shear wave velocity of frozen soil mixtures for the estimation of the silt fraction effect. A shear box incorporated with k-type thermocouple and bender elements is designed for the test. The specimens with silt fractions of 0, 30, and 70% by weight (W silt /W sand × 100%) are mixed and placed into the shear box at the fixed relative density of 60% and degree of saturation of 15%. The specimens are frozen to −5 °C, and the direct shear test is conducted after freezing. Tests show that the peak and residual shear strengths change according to the silt fraction. The shear wave velocity rapidly increases after freezing and gradually decreases during shearing. Both the shear strength and shear wave velocity indicate minimum values at a silt fraction of 30%. This study demonstrates that the consideration of silt fraction should be carried out since fine particles in frozen soil mixtures may change the strength and stiffness. Keywords Frozen soil mixtures · Shear strength · Shear wave velocity

1 Introduction Natural deposits comprise sand particles with various fines content. The fines content determines the soils’ behavior as coarse or fine-dominant. The Unified Soil Classification System (USCS) has classified soils as being coarse or fine-grained based on the fines fraction at 50%. However, numerous studies have reported that mixture responses significantly change at fines fraction lower than 50% [2, 9, 10]. The characteristics of soils significantly change when the pore water is frozen. The strength and stiffness dramatically increase owing to the ice formation between soil particles [3, 4, 11]. The amount of ice formation may vary in accordance with S. Y. Kim · J.-S. Lee (B) School of Civil, Environmental and Architectural Engineering, Korea University, Seoul, Republic of Korea e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_16

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fines content. However, the overall estimation of fines content effect on the strength and stiffness of frozen soil mixtures is insufficient. The objective of this study is to investigate the fines content effect on frozen soil mixtures by considering silt as a fine particle. This paper starts with a description of the test setup, followed by experimental results. Then, the analyses demonstrate the silt fraction effect on the strength and shear wave velocity of frozen soil mixtures.

2 Experimental Setup 2.1 Test Device Direct shear apparatus is designed for characterization of frozen soil mixtures. The upper and lower shear boxes are separated to eliminate additional friction between the boxes. A load cell is connected to the lower shear box for the measurement of shear strength. The capacity of load cell is 7 MPa regarding the dimensions of shear box. Note that the inner dimensions of the box are 70 mm in width and length, and 35 mm in height. In addition, a pair of bender elements is installed on the shear box for measurement of shear wave signals. Each bender element propagates and receives the shear wave through the specimen. The measured shear wave signals are used to determine a first arrival time for the calculation of shear wave velocity. The designed devices are placed into an ice chamber to freeze soil mixtures.

2.2 Specimens Sand is mixed with silt at fractions of 0, 30, and 70% by weight (W silt /W sand × 100%). Specific gravities of soil mixtures are 2.62, 2.65, and 2.67, respectively. The maximum void ratios are 1.02, 0.81, and 1.01, and the minimum void ratios are 0.57, 0.42, and 0.45, respectively. The soil mixtures are partially saturated at 15% degree of saturation for the ice formation between soil particles after freezing. The mixed soil mixtures are placed into the shear box at an identical relative density of 60%. The prepared soil mixtures are frozen to −5 °C prior to shearing.

3 Test Results and Analyses 3.1 Shear Strength The direct shear test is carried out using frozen soil mixtures with silt fractions at 0, 30, and 70% subjected to an identical normal stress of 10 kPa. Shear stress and

Estimation of Shear Strength and Shear Wave Velocity …

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800 SF = 0 % SF = 30 % SF = 70 %

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Fig. 1 Shear behavior of soil mixtures: a shear stress according to horizontal displacement; b vertical displacement according to horizontal displacement

vertical displacement according to horizontal displacement are plotted in Fig. 1. The peak and residual shear strengths decrease with an increase in silt fraction from 0 to 30% followed by subsequent increase between silt fractions of 30 and 70% as shown in Fig. 1a, b shows that vertical displacement of the soil mixture with 30% silt fraction is significantly greater than that with 0 and 70% silt fractions. The direct shear test results display that the transitional soil behavior is shown at a silt fraction of 30%.

3.2 Shear Waves Typical shear wave signals observed before freezing, during freezing, after freezing (i.e., before shearing), during shearing, and after shearing are gathered as shown in Fig. 2. First arrivals are indicated by dotted circles for measurement of shear wave velocity. Note that the shear wave velocity can be calculated by dividing the tip-to-tip distance between bender elements by first arrival [7], and the value has been used to estimate stiffness of soil mixtures [1, 6]. Figure 2 presents that the shear wave velocity rapidly increases after freezing owing to ice formation [8]. Furthermore, the shear wave velocity of frozen soil mixtures at −5 °C is faster than that at −2 °C since the unfrozen water can be frozen as temperature decreases under subzero conditions [5]. The shear wave velocity slightly increases during shearing owing to increment in shear stress. However, the shear wave velocity decreases after shearing because the shear failure occurs and formed ice bonds are broken.

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Before freezing

During freezing (T = -2 oC)

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After shearing

0.0

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Fig. 2 Typical shear wave signals during freezing and shearing. T and δ denote temperature and horizontal displacements, respectively

3.3 Silt Fraction Effect For evaluation of the silt fraction effect on frozen soil mixtures, shear strength after freezing, shear wave velocity before and after freezing are plotted in Fig. 3. The shear strength and shear wave velocity at the silt fraction of 30% show the lowest values since the contacts between sand particles can be significantly interrupted by silt at that silt fraction. Prior to freezing, the shear wave velocity at a silt fraction of 30% is slightly lower compared to the corresponding values at 0 and 70%. However, the shear strength and shear wave velocity at 30% silt fraction after freezing show significant lower values compared to the other silt fractions. The amount of ice formation may change despite the identical degree of saturation because the voids vary with respect to the silt fraction.

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4 Summary and Conclusions The goal of this study is to estimate the silt fraction effect on the shear strength and shear wave velocity of frozen soil mixtures. The soil mixtures at the silt fractions of 0, 30, and 70% are prepared at the degree of saturation of 15% and relative density of 60%. The direct shear test is conducted after freezing, and the shear wave velocities are measured during freezing and shearing. The main observations are as follows: • Shear strength presents transitional behavior at a silt fraction of 30% since the contacts of sand particles are interrupted by silts. • Shear wave velocity varies during freezing and shearing owing to ice formation and breakage of formed ice bonds between soil particles. • Silt fraction effect on shear strength and shear wave velocity is facilitated after freezing because the amount of ice formation varies with silt fraction despite identical degree of saturation. Acknowledgements This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (NRF-2017R1A2B3008466).

References 1. Byun YH, Han W, Tutumluer E, Lee JS (2016) Elastic wave characterization of controlled lowstrength material using embedded piezoelectric transducers. Constr Build Mater 127:210–219 2. Choo H, Burns SE (2015) Shear wave velocity of granular mixtures of silica particles as a function of finer fraction, size ratios and void ratios. Granul Matter 17(5):567–578 3. Kang M, Lee JS (2015) Evaluation of the freezing–thawing effect in sand–silt mixtures using elastic waves and electrical resistivity. Cold Reg Sci Technol 113:1–11 4. Kim SY, Hong WT, Lee JS (2018) Silt fraction effects of frozen soils on frozen water content, strength, and stiffness. Constr Build Mater 183:565–577

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5. Konrad JM, Samson M (2000) Influence of freezing temperature on hydraulic conductivity of silty clay. J Geotech Geoenviron Eng 126(2):180–187 6. Lee C, Truong QH, Lee W, Lee JS (2009) Characteristics of rubber-sand particle mixtures according to size ratio. J Mater Civ Eng 22(4):323–331 7. Lee JS, Santamarina JC (2005) Bender elements: performance and signal interpretation. J Geotech Geoenviron Eng 131(9):1063–1070 8. Park JH, Lee JS (2014) Characteristics of elastic waves in sand–silt mixtures due to freezing. Cold Reg Sci Technol 99:1–11 9. Rahman MM, Lo SR, Gnanendran CT (2008) On equivalent granular void ratio and steady state behaviour of loose sand with fines. Can Geotech J 45(10):1439–1456 10. Thevanayagam S (1998) Effect of fines and confining stress on undrained shear strength of silty sands. J Geotech Geoenviron Eng 124(6):479–491 11. Ting JM, Torrence Martin R, Ladd CC (1983) Mechanisms of strength for frozen sand. J Geotech Eng 109(10):1286–1302

Problems of Design, Construction and Operation of Transport Infrastructure in Cold Regions

Analytical Modeling of the Dynamic Behavior of the Railway Track on Areas of Variable Stiffness Alexey A. Loktev , Z. T. Fazilova , A. A. Zaytsev

and N. L. Borisova

Abstract The chapter is devoted to transition sections of the interference in a railway track of the different design and stiffness parameters of the subgrade. The objective of the research is the improvement of technical solutions to arranging transition sections of the track on high-speed lines. To achieve the aim, an analytical model of the investigated section of the railway track was created and the calculation of stress–strain behavior of this model was carried out. During analytical modeling, we determined the values of stresses, deformations, and forces arising in certain structural elements, as a result of rolling running. The analysis of the obtained results allows to identify the elements of the track structure susceptible to the development of destructive processes. The offered model can be recommended as the algorithm for selecting stiffness parameters (deformation and shear moduli) of the track structure, the base and body of the subgrade, when trains move at different speeds and with different axle loads. Keywords Transverse deformation · Sections of variable stiffness · Settlement of track · Grade · Elastic wave · Deformation · Elastic shrinkage · Track cross section · Transversely isotropic plate · Dynamic loading · Dynamic deflection

1 Introduction According to «The strategy of the railway transport development in the Russian Federation up to 2030», it is planned to expand the railway infrastructure at 660 km in the Arctic zone. It is supposed to construct some bridge crossings over the Nadym and the Ob during the implementation of this project. Complicated conditions of soil behavior of the solid subgrade on the approaches to engineering structures, caused by an abrupt change in the track stiffness during the transition from the A. A. Loktev · Z. T. Fazilova (B) · A. A. Zaytsev Russian University of Transport MIIT, Moscow, Russia e-mail: [email protected] N. L. Borisova Military University of the Ministry of Defence, Moscow, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_17

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ballasted permanent way to the ballastless one, lead to a great number of defects and deformations in it. In these zones, there is an increased accumulation of track geometry displacement, which causes an increase in the volume of work on the track maintenance and reduces the service life of track elements, limiting the speed of train traffic on these sections. These negative aspects have a particular relevance to rapid and high-speed rail lines. The negative impact on the track manifests itself in the decrease in the service life of the rails, the occurrence of contact-fatigue defects in the rail head, the breakdown of intermediate rail fastenings and reducing the service life of sleepers, the decrease in the turnaround cycles of the alignment of the track in section by 29– 38%, the cumulative transverse deformation in the ballast section, and the increase in dynamic stresses on the solid subgrade [1]. Currently, in order to connect these sections, special transition structures of the track have been developed and are being applied, the design of which ensures a stable smoothness of train running on the approaches to engineering structures, and the dynamics [2, 3] of the track is improving. The experience in the construction and operation of structures in the areas of transitional stiffness, as well as the results of the observations of the test section, performed on the St. Petersburg–Moscow line using geogrids, after its strengthening for high-speed passenger trains, showed that, in general, on all sections a significant improvement of the track condition has been achieved, and the necessary track stability was provided [3–5]. However, it should be noted that at present it cannot support the necessary smoothness of running at speeds of 200 km/h and more.

2 Methods Traditional methods for calculating the parameters of the behavior of the railway track, caused by the dynamic train load and due to natural oscillations, do not allow to take into account the anisotropic properties of the track design, especially ballastless, in tangent and curved sections [5–7]. To this end, an attempt is made to create an analytical model of the railway track dynamic behavior in the form of a transversely isotropic plate with various stiffness parameters, which is described by equations of the Ufland–Mindlin–Reissner type, taking into account the inertia of the rotation of the cross sections and the deformation of the transverse shear [7]:  Dr

   ∂ 2ϕ ∂w h3 ∂ 2ϕ ϕ 1 ∂ϕ − D − ϕ = −ρ + + h K G , θ 2 rz 2 ∂r r ∂r r ∂r 12 ∂t 2     2 ∂ 2w ∂ w ∂ϕ 1 ∂w K Gr z + K G − ϕ =ρ 2, − rz 2 ∂r ∂r r ∂r ∂t

(1) (2)

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 ∂ 2u u 1 ∂u ∂ 2u − C Cr + = ρh , θ ∂r 2 r ∂r r2 ∂t 2  2  ∂ v 1 ∂v ∂ 2v v = ρh Ck + , − ∂r 2 r ∂r r2 ∂t 2  2  ∂ ψ ψ 1 ∂ψ h3 ∂ 2ψ − K hG Dk − + ψ = −ρ θ z ∂r 2 r ∂r r2 12 ∂t 2 3

3

(3) (4) (5)

3

h h h where Dr = 12 Br , Dθ = 12 Bθ , Dk = 12 Bk , Cr = h Br , Cθ = h Bθ , Ck = Eθ Er , Bk = G r θ ,Er σr = h Bk ,Dr θ = Dr σθ + 2Dk ,Br = 1−σr σθ , Bθ = 1−σ r σθ 5 E θ σθ , K = 6 , Dr , Dθ and Cr , Cθ —respectively, stiffness in bend and in tension compression for axes r, θ ; Dk —stiffness in torsion; C k —shear stiffness; E r , E θ and σ r , σ θ —elastic modulus and Poisson ratio for axes r, θ ; Grz , Gθ z —shear modulus in planes r z and θ z , respectively; w(r, θ )—normal displacement of a middle plane, u(r, θ ) and v(r, θ )—tangential displacements of a middle plane, respectively, along the coordinates r, θ ; ϕ(r, θ ) and (r, θ )—arbitrary sought functions of the coordinates r, θ . This model allows to take into account not only the dynamics of the applied load, but also the dynamics of the changes in the deformation and strength characteristics, both the track design and the roadbed [8, 9], which will help to develop functional requirements and standards for transitional structures.

3 Results While designing a model in use, we relied on the data of field tests on the approaches to the bridges. As a result, graphical curves of dynamic deflection in the zone of interaction between the wheel pair and the railway track were made for various ratios of the elastic moduli and shear moduli with the following parameter values of vehicle dynamic loading to the track: m = 25 t, h = 500 mm, V 0 = 20 m/s, ρ = 7850 kg/m3 [9–11]. The analysis of the given dependencies of the anisotropic properties of the plate of the ballastless subgrade on the characteristics of the dynamic impact shows that with a decrease in the ratio E θ /Er , there is an increase in the deflection depression up to the value when E θ /Er < 1; with an increase in the ratio E θ /Er >1, decrease in deflection is observed (see Fig. 1). Based on the assumption that a ballastless track has transversely isotropic properties for different shear moduli in a direction perpendicular to the plane of the embankment (G r z ), dependencies between the dynamic deflection and the time for different ratios G r z /Er are made, as shown in Fig. 2. The values of the relationship G r z /Er , are given in numbers on the curves.

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Fig. 1 Dependence of the dynamic deflection on time for different values of the ratio E θ /Er

Fig. 2 Dependence of the dynamic deflection on time for different values of the ratio G r z /Er

The analysis of the dependencies shows that when G r z /Er = 0.54, the ballast section has isotropic properties, and an increase in the value of the ratio of moduli G r z /Er leads to a decrease in deflection depression. The correlation between the results of the analytical calculations and the field tests of track settlement on the approach to the bridge structure in Km 56 of the railway milestone 6 on the Saratov–Kolotsky line (an even line), presented on Figs. 1 and 2 by dashed lines, shows a satisfactory agreement of the results between the higher value of the deflection and the duration of the track deformation [10–12].

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Fig. 3 Dependence of the maximum deflection on the ratio E θ /Er for different values of E˜

Dependences of the maximum deflection on the ratio E θ /Er for different values ˜ presented on Fig. 3, of the corrected modulus of the track structure deformation E, show that the maximum deflection decreases with the increase in the ratio E θ /Er and grows with the increase in linear stiffness of the wheel–rail contact E˜ = (Curve 1− corresponds to E˜ = 3.6 × 10−6 , Curve 2 − E˜ = 2.5 × 10−6 , Curve 3 − E˜ = 1.4 × 10−6 ). Thus, by analyzing and comparing the theoretical dependencies obtained for different values of the mechanical parameters of the roadbed with the data obtained by calculation, it can be noticed that by changing the mechanical parameters of the soil, it is possible both to increase and to reduce the deformation of the railway track. The existed correspondence between the obtained data of mathematical modeling and experimental research makes it possible to recommend the application of the proposed methodology in solving the main tasks to ensure the stability of the behavior of the railway track, both in the operation of existing lines and in the design of high-speed lines [3, 13]. Another trend of the research was the use of analytical modeling of the dynamic behavior of a track in solving the problem of optimizing the conditions of the wheels and the rail interaction [4, 14]. If there are defects on the wheelsets as built-up tread, slid flat, steep flange, headand-web separation, shelled tread, as well as short irregularities on running surface of rail, the nature of the interaction between the wheel and the rail will be significantly different from the classical contact problem of rolling a cylinder along a cylinder. Under these conditions, traditional models do not allow to obtain adequate values of dynamic force of contact and depression of assembled rails and sleepers; therefore, it is proposed to use other dependencies that unite the force of interaction between the wheel and the rail, local deformations of materials of contacting bodies [10, 15].

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The proposed models are particularly relevant for sections of the track with variable stiffness, since the interaction of the wheel and the rail on them is subject to more complex mathematical relationships, taking into account not only the parameters of the wheel pair and continuously welded rail, but also the function of stiffness in different directions of anisotropy. Viscoelastic model with fractional derivatives of Riemann–Liouville (6), the elastic–plastic models of Kilchevsky (7) and Aleksandrov–Kadomtsev (8) were used as a basis for the research because they take into account many aspects of the train movement and the track condition [2, 11–13]: γ

γ

γ

γ

P + τ D P = E 1 τ D (α − w),

d D P= dt γ

t 0

P(t − t  ) dt  Γ (1 − γ )t γ

⎧ 2/3 dP/dt > 0, P < Pb , ⎨ bP , α = b P 2/3 + Pd, dP/dt > 0, P > Pb , ⎩ 2/3 b P + Pmax d, dP/dt < 0, Pmax > Pb , ⎧ 2/3 d p/dt > 0, Pmax < P1 , ⎨ bP , α = (1 + β)c1 + (1 − β)Pd, d p/dt > 0, Pmax > P1 , ⎩ 2/3 bf P + αp (Pmax ), d p/dt < 0, Pmax > P1 ,

(6)

(7)

(8)

here α—local crush of a rail and a wheel material, w—displacement of the bottom of the rail base, γ (0 0.5εV . In this case, between Fig. 6a, b there is a significant difference only near to the pipeline. It means that it is necessary to exclude frost heaving in the area adjacent to the pipeline. Figure 7 shows the results of the calculation of pipeline vertical displacements. Here, there is distinctive feature—near the section of frost heave, the pipeline first bends downwards, which is also noted in the measurements. The standard deviation of displacements from measured values was 0.013 m. Figure 8 shows the results of the calculation of von Mises stress. In the emergency site, von Mises stress exceeds the ultimate tensile strength of steel (σ v > F tu ). Fig. 5 Results of calculation of the relative variation of the volume due to frost heaving of soil εV

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Therefore, the authors concluded that the frost heave led to an unacceptable change in the stress–strain state of the pipeline and depressurization. The authors have considered the following ways to protect this pipeline from frost heaving: ring thermal insulation on the pipeline surface; soil bedding under bottom of pipe; electrical heating of the soil near the bottom of pipe. Thermal insulation was investigated in [8], soil bedding in [24], and electrical heating in [25]. Based on the results of previous studies, it was proposed to use thermal insulation or soil bedding. The owner of the pipeline decided to use ring thermal insulation. The thickness of

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the insulation was calculated in accordance with the methodology in [8]. The last observation (2019) showed the stability of the spatial position of the pipeline.

5 Conclusion A mathematical model for predicting frost heaving under pipelines has been developed. The model describes frost heaving like an ensemble of interrelated processes: heat and mass transfer in the soil, deformation of the soil, and deformation of the pipeline. The model takes into account the influence of atmospheric processes through the boundary conditions. The accuracy of the mathematical model is confirmed by measuring of the spatial position of the pipeline: The standard deviation of the calculated and experimental data is not more than 0.013 m. The negative temperature of gas condensate provoked freezing of the clay loam, the transfer of water to the freezing front, and an increase in the volume of the soil. As a result, a change in the stress–strain state of the pipeline led to the depressurization of pipeline. Therefore, pipelines with a negative product temperature of less than −2 °C require special engineering solutions for protecting from frost heaving. Soil bedding and soil replacement is not needed in accordance with the methodology in [8]. Thermal insulation was used to protect pipeline from frost heaving. Over the past two years (2017–2019), it provides stability of the spatial position of the pipeline.

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References 1. Gorkovenko AI (2006) The bases of theory for calculating the spatial position of an underground pipeline under the influence seasonal processes, 1st edn. Tyumen Oil and Gas University, Tyumen 2. Markov EV, Pulnikov SA (2018) Procedure of providing engineering protection from frost heaving of underground trunk pipelines by the soil bed. High Educ InstS News Neft’igaz 3:91–101 3. Mikhaylov PYu (2012) Dynamics of heat and mass transfer processes and the heat and force interaction of freezing soils with underground pipeline, 1st edn. University of Tyumen, Tyumen 4. Markov EV, Pulnikov SA, Sysoev YS, Gerber AD (2017) Development of mathematical model of heat and mass transfer in soil, with provision for gradients of soil–water and soil–salt potentials. Part 1. Int J Appl Eng Res 12(4):4340–4344 5. Markov EV, Pulnikov SA, Sysoev YS, Gerber AD (2017) Development of mathematical model of heat and mass transfer in soil, with provision for gradients of soil–water and soil–salt potentials. Part 2. Int J Appl Eng Res 12(19):8717–8722 6. Markov EV, Pulnikov SA, Sysoev YS, Gerber AD (2017) Development of mathematical model of heat and mass transfer in soil, with provision for gradients of soil–water and soil–salt potentials. Part 3. Int J Appl Eng Res 12(21):11146–11151 7. Markov EV, Pulnikov SA, Gerber AD (2018) Development of mathematical model of component mass transfer of water–salt solution in heaving soils based on the kinetic theory of liquids. Bull South Ural State Univ. Series of “Math Mech Phys” 10(1):37–44. https://doi.org/ 10.14529/mmph180105 8. Markov EV, Pulnikov SA, Sysoev YuS (2018) Evaluation of the effectiveness of ring thermal insulation for protecting a pipeline from the heaving soil. J Eng Sci Technol 13(10):3344–3358 9. Loh EWK, Wijeyesekera DC, Ciupala MA (2017) A new method for estimating the moisture content and flexibility of polymerised bentonite clay mat. J Eng Sci Technol 12(4):948–957 10. Ajbinder AB (1991) Calculation of main and field pipelines for strength and stability, 2nd edn. Nedra, Moscow 11. Al-Dawery SK, Reddy SS (2017) An experimental study on the rheological properties of conditioned municipal activated sludge. J Eng Sci Technol 12(1):138–154 12. Globus AM (1969) Experimental soil hydrophysics. Methods for determining the potential and coefficients of soil moisture transfer. 1st edn. Gidrometeoizdat, Leningrad 13. Karkush MO, Resol DA (2017) Geotechnical properties of sandy soil contaminated with industrial wastewater. J Eng Sci Technol 12(12):3136–3147 14. Danielyan YuS, Yanitsky PA (1983) Features of the non-equilibrium redistribution of moisture during freezing–thawing of dispersed rocks, 1st edn. Nedra, Minsk 15. Mualem Y (1976) A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour Res 12(3):513–522 16. Mualem Y, Miller EE (1979) A hysteresis model based on an explicit domain-dependence function. Soil Sci Soc Am 43:1067–1073 17. Halperin BM (1970) Turbulent heat and moisture exchange on the surface of land and waters, 1st edn. LGMI, Leningrad 18. Nikolsky BP (1968) Chemist Handbook. Volume 5. Raw materials and industrial products of inorganic substances, processes and apparatus, corrosion, electroplating, chemical current sources. 1st edn. Chemistry, Moscou-Leningrad 19. Matveyev LT (1984) The course of general meteorology. Physics of the atmosphere. 1st edn. Hydrometeoizdat, Leningrad 20. Klimenko VV, Klimenko AV (1997) Energy, nature and climate, 1st edn. MEI, Moscou 21. Korolev VA, Bludushkina LB (2015) Correlation between the potential of moisture in soils with the parameters of water evaporation from them. Eng Geol 3:22–33 22. Pavlov AV (1975) Soil heat exchange with the atmosphere in the northern and temperate latitudes of the USSR, 1st edn. YKN, Yakutsk

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23. Velly YuY, Dokuchaeva VI, Fedorov NF (1977) Handbook of construction on permafrost, 1st edn. Stroyizdat, Leningrad 24. Markov EV (2018) Procedure of providing engineering protection from frost heaving of underground trunk pipelines by the soil bed. High Educ InstS News NEFT’ IGAZ 3:91–101 25. Markov EV, Pulnikov SA (2018) Optimization of soil electrical heating for underground pipelines protection from frost heaving. Gas Ind 11:32–41

Producing Sleepers from Modified Wood for Railways in Cold Regions Ilya Medvedev , Vladimir Shamaev , Dmitry Parinov and Oksana Shakirova

Abstract The technology of end-grain treatment of wood workpieces for sleeper production under pressure and treatment modes has been developed. Pilot plant for end-grain wood treatment under pressure has been created. Technological modes for producing sleepers with high-performance characteristics of softwood have been tested using the installation which enables to combine technological operations— drying, treatment, and wood pressing. The resulting sleepers can be used in the Extreme North conditions. According to the developed technology an experimental batch of half ties for underground railway system and a batch of sleepers to carry out tests have been produced on the pilot plant. Keywords Wood · Treatment · Modeling · Drying · Ressing · Sleepers

1 Introduction In the Russian Federation, at least 10% of the areas are located in conditions where low temperatures of up to −50 °C are observed for more than half a year, and only the surface layer of the ground thaws out in summertime, the rest part is perpetually frozen soil. Under these conditions, use of reinforced concrete sleepers is impossible because of their cracking at low temperatures and drowning at positive temperatures. The main use is found for sleepers made of pine, but their service life is short (10– 15 years). A technology for producing sleepers from modified birch and aspen wood has been developed to meet the country’s need for railway sleepers for cold regions (about 200 thousand units per year). These are low-demand species and millions of cubic meters of this wood are rotting in the cutting areas. This technology is based on compaction of soft hardwood with two-fold increase in strength and wear resistance (up to oak wood) [1–4]. Hardwood is used to produce sleepers in Western Europe, the USA, and Japan (oak, beech, and wood from Africa, Southeast Asia, and Latin I. Medvedev (B) · V. Shamaev · D. Parinov · O. Shakirova Voronezh State University of Forestry and Technologies named after G.F. Morozov, Voronezh City, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_20

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America) [5–8]. At present, a large number of wood modification methods have been developed [9–12], but they are not widely used for the production of sleepers. Traditional technology for producing railway sleepers consists in treatment of preforms (dried to a moisture content of 30 ± 5% in autoclaves at a pressure of 8–15 atmospheres and a temperature of 100–110 °C) with oily antiseptics (coal oil, shale oil, absorbing oil, thermal cracking fluid, anthracene oil, etc.) or aqueous solutions of salts (chromium copper, arsenic, sodium pentachlorophenolate fluoride, and others) [13, 14]. A common drawback of these methods is the need to pre-dry the workpieces to the moisture content of 25% by the method of atmospheric drying (6–9 months) or chamber drying (10–14 days), and when it is impregnated with water antiseptics. There is still a necessity to re-dry the sleepers to the moisture content of 22%. New opportunities have appeared after justifying the method of end-grain throughtreatment of large-sized workpieces under pressure, by analogy with the movement of fluid in a growing tree from butt (root) to the crown (top) [15, 16].

2 Materials, Methods, and Equipment The scheme of the experimental installation for through treatment of sleeper workpieces is shown in Fig. 1. The 3D model of the experimental installation for the production of sleepers is shown in Fig. 2. Birch wood (Betula verrucosa L.) has been used for the experiments. Thermocatalytic cracking fluid (TCF) has been used as an antiseptic coming to coal oil according to its characteristics. The production of sleeper workpieces at the experimental installation includes three main technological operations—drying, treatment, and pressing. The first operation is drying of birch sleeper bar with an initial moisture content of 70–80% in oily antiseptic. A bar is laid in the thermally insulated working bath 1. The TCF antiseptic requires temperature of 130 °C and the antiseptic is pumped into the working bath 1 with the help of the pump unit 8 through the pipeline from the tank 6. Further, the

Fig. 1 The scheme of the experimental installation for through-treatment of sleeper workpieces. 1—receiver for impregnating fluid; 2—receiver for harvesting; 3—pump station tank; 4—drain tank; 5—pipeline; 6—control panel; 7—electric dosing plunger unit

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Fig. 2 The 3D model of an experimental installation for the production of modified wood sleepers. 1—working bath; 2—frame; 3—hydraulic station; 4—hydraulic cylinders; 5—tank for cold antiseptics; 6—tank for hot antiseptics; 7—heat exchanger; 8—pump unit for pumping hot antiseptics; 9—pump unit for pumping cold antiseptics

antiseptic is pumped back to the tank 6 along the parallel pipeline with the pump unit 9. At the same time, the antiseptic temperature decreases sharply. It is necessary to heat the antiseptic carried out due to the work of heating elements installed in the double bottom of the tank 6. The antiseptic circulation continues throughout the whole time of sleeper workpiece drying. The drying process is controlled by the temperature inside the sleeper workpiece using thermocouples mounted in it in the amount of at least three pieces. As soon as the temperature inside the wood reaches 100 °C, the moisture content of the workpiece is not more than 35%, and the bound moisture begins to evaporate—the duration of the evaporation process of bound moisture, depending on the ambient temperature, is 20–25 h. The temperature in the sleeper workpiece rises up to 107–110 °C. The vapors (resulting in the process of sleeper workpiece drying) are condensed in a heat exchanger 7. Uniaxial pressing of sleeper bar is carried out due to the impact of the pressure plate (punch) located inside the working bath 1 to improve the performance characteristics of sleepers. The pressure plate is driven by hydraulic cylinder rods 4 mounted on the frame 2. The pressing process is carried out stepwise and controlled along the stroke of the hydraulic cylinders rods (the stroke of the rods is not more than 4–5 cm), which enables to increase the workpiece density to 750–800 kg/m3 . The work of hydraulic cylinders is provided by hydraulic station 3. The next process step is an additional surface treatment. Treatment of sleeper bars on the experimental installation is carried out by the method of hot-cold bathing. The antiseptic in the cold bath 3 (preheated to a temperature of 40 °C) is pumped through the pipeline by the pump unit 7 into the working bath 5, at the same time

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hot antiseptic is pumped out of the working bath 5 into the hot antiseptic tank 1. The working bath is controlled so that the level of antiseptic does not fall below the height of the workpiece, so that air suction does not take place. Treatment is carried out according to the following procedure: hot liquid is replaced with cold one in 5 min, followed by wood conditioning in cold liquid for 4 h.

3 Discussion of Results Figure 3 shows the graphs of technological process results for specimen No. 1. To increase the drying rate of the specimen No. 1, the diameter of the mesh laid between the pressure plate and the specimen and between the bottom of the working bath and the specimen is changed from 1 to 2.5 mm. The results of studies on the depth of TCF end-grain treatment of sleeper are presented in Table 1. As it can be seen from Table 1, the content of antiseptic is 5.57% even at a distance of 200 mm from each end, which meets the requirements of State Standard 78-2004. To determine the humidity, antiseptic content and depth of impregnation methods described in State Standard were used. Table 2 shows the depth of penetration of TCF antiseptic in the workpiece across the fibers. Measurements have been taken every 200 mm length of the sleepers on the surface of the plates. As it can be seen from Table 2, the depth of treatment across the fibers ranges from 9.1 to 40.65 mm, which exceeds the standard value (5 mm).

Fig. 3 Graph of changes in temperature, pressing and moisture content of wood specimen No. 1. 1—curve of moisture values of the workpiece during the drying process; 2—curve values of the pressing degree in the pressing process; 3—temperature curve in the process of modified wood production

Table 1 The antiseptic content in specimens Distance from the end of the sleeper

0

200

500

800

The content of TCF antiseptic (%)

17.5

5.57

8.22

20.4

Producing Sleepers from Modified Wood … Table 2 Depth of wood treatment across the fibers

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Distance from the end of a sleeper

Depth of treatment (mm)

0

40.65

200

10.3

400

9.1

600

16.87

800

38.9

1,000

24.83

1,200

13.27

1,400

10.29

1,600

15.9

1,750

30.17

The average value for the sleeper length

21.03

Table 3 presents the results of testing on wood specimens with dimensions 20 × 20 × 30 mm (the last dimension is along the fibers) to determine the density and moisture content in the resulting sleepers. It can be concluded that specimens taken from the edges and ends of sleepers have the highest density. Also, specimens taken from the ends of sleepers have less moisture content. The average moisture content and density of the specimens is 27.2% and 703 kg/m3 . As it can be seen from Table 3, wood density of sleepers corresponds to State Standard R 56879-2016. There is an excess of 6% in terms of moisture content, i.e. drying time is necessary to be increased. Tests for ultimate compressive strength along the fibers have shown that σ comp is 41.5 MPa for wood with a moisture content of 22% and 65.5 MPa—for wood with a moisture content of 12%. On the basis of the obtained results, a technological regulation for drying, treatment, and pressing wood has been developed using a combined method of sleepers’ production. Table 3 The results of determining the density and moisture content of modified wood workpieces

№ of specimen

Specimen № 1 Density (kg/m3 )

Moisture content (%)

1

756.4

22.9

2

658.0

28.1

3

661.2

36.4

4

675.8

36.6

5

749.6

31.0

6

721.6

25.3

7

641.3

25.5

Average

694.8

29.4

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1. The workpiece is loaded into the working bath of the pilot unit SPK-1M manually by operators. After loading, the hydraulic station is turned on, and the hydraulic cylinder rods are lowered until the pressure plate touches the upper part of the workpiece. The bath cap is attached to the bath manually. Heating elements are turned on in containers with a hot antiseptic, the temperature of which is brought up to 120 °C four hours before the start. 2. The pump unit is turned on and hot antiseptic is fed into the working bath from the tank with hot antiseptic. From the working bath, the antiseptic is pumped back to the tank with the hot antiseptic by the second pump unit. The circulation of antiseptic is carried out for 68 h, when heating elements are turned on in a hot container. 3. After the drying process is completed, the treatment process starts by pumping out hot antiseptic and simultaneously pumping cold antiseptic from the tank with cold antiseptic at a temperature not lower than 40 °C. The treatment process takes 4 h from the time of antiseptic change. 4. Further, according to the technological regulations, the process of wood pressing with simultaneous circulation of hot antiseptic follows. The pressing process continues for 7 h after the application of pressure on the workpiece. 5. The end of the process is cooling and conditioning. Cooling takes place in a hot antiseptic for 10 h. Air conditioning is carried out on the roller table for 2 h. The finished sleeper is obtained with a section of 180 × 250 mm and a length of 2,750 mm with moisture content of 22%, density of 720–780 kg/m3 . The obtained parameters of the technological regimes make it possible to produce sleepers made of modified wood with improved performance characteristics (Fig. 4). According to the developed technology an experimental batch of half ties for underground railway system and a batch of sleepers to carry out tests have been produced on the pilot plant. The half ties have been laid at Chistye Prudy metro station in Moscow, and the sleepers have been laid at Scherbenka station on the experimental ring of Russian Railways JSC. The tests have been carried out for four years in underground railway system and two years on the ring of Russian Railways. The test results have found that wear of modified sleepers and half ties is about 3 times less than wear of pine sleepers and the average service life of sleepers made of modified wood will be about 50 years. Based on the tests, Russian Railways JSC has approved Specifications No. 5888-001-34017041041-2012 M “Modified wood sleepers”. An experimental batch of broad gauge sleepers is currently being prepared for testing in the Extreme North. The materials presented in this article have been obtained within the framework of the state task of Ministry of Education and Science of Russia № 11.3960.2017/4.6.

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Fig. 4 Graph of drying, treatment and pressing parameters. 1—curve of moisture values of the workpiece during the drying process; 2—curve of pressing degree values in the pressing process; 3—temperature curve in the process of modified wood production

4 Conclusion 1. A technology has been developed, a pilot plant has been tested and a batch of modified wood sleeper has been produced corresponding to State Standard R 56879-2016 “Modified wood Workpieces for sleepers and power line poles”. 2. The optimal modes of treatment, drying and pressing of wood have the following values: hot antiseptic temperature—120 °C, warm-up and drying time of wood— 38 h, treatment time—4 h, pressing time—17 h, specific pressure—0.8 MPa, cooling time—6 h, pressing degree—22%. 3. Modified wood, obtained in optimal conditions, has the following characteristics: density—700 kg/m3 , moisture content—22%, compressive strength along fibers—41.5 MPa, treatment depth: across the fibers—5.5 mm, from the end— 110 mm.

References 1. Westin M (2010) Durability of modified wood—laboratory versus field performance. Technical Research Institute of Sweden, Boras, Sweden, 142 2. Official Website of Kebony Company—Mode of access. http://kebony.com/en/products/—title from screen 2014/02/21

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3. Shamaev V, Medvedev I, Parinov D (2018) Study of modified wood as a bearing material for machine-building international conference on Aviamechanical engineering and transport (Avia ENT). Adv Eng Res 158:478–482 4. Shamaev V, Medvedev I, Parinov D, Shakirova O, Anisimov M (2018) Investigation of physical and mechanical properties and microstructure of modified wood produced by self-pressing method. Acta fakultatis xylologiae Zvolen 10 5. Ovchinnikov V, Zobov S (2010) Increase of service life of wooden sleepers Path and track facilities № 8, 9–11 6. State Standard R 56879-2016 Modified Wood (2016) Workpieces for sleepers and power lines poles. Technical conditions intr. 2016-02-29—18 7. Patent 2481430 RF (2013) A method of sleepers manufacturing Taimarov, M. appl. 29.12.2011; publ. 10.05.13. Bull № 13 8. Medvedev I, Shamaev V, Parinov D (2018) Resource-saving production of modified wood sleepers path and track facilities, № 11, 30–32 9. Lekounougou S, Kocaefe D, Oumarou N, Kocaefe Y, Poncsak S (2011) Effect of thermal modification on mechanical properties of Canadian white birch (Betula papyrifera). Int Wood Prod J 2(2):101–107 10. Tshabalala M, McSweeny J, Rowell R (2012) Peat treatment of wet wood fiber: a study of the effect of reaction conditions on the formation of furfurals. Wood Mat Sci Eng 7:202–208 11. Sandberg D, Haller P, Navi P (2013) Thermo-hydro and thermo-hydro-mechanical wood processing: an opportunity for future environmentally friendly wood products. Wood Mat Sci Eng 8(1):64–88 12. Rowell R, Andersone I, Andersons B (2012) Heat treatment. Chapter 14 in handbook of wood chemistry and wood composites, 2nd edn. CRC Press, 511–536 13. State Standard 20022.0-93 Wood Protection (1995) Security settings—Instead of State Standard 20022.0-82; Intr. 1995-01-01. M.: Standards Publishing House, 104 14. State Standard 78-2004 (2004) Wooden sleepers for broad gauge railways [text]—Instead of State Standard 78-89; Intr. 2006-01-01. M.: Mezhgos. Council for Standardization, Metrology and Certification; Standards Publishing House, 13 15. Shamaev V, Manaev V, Kondratyuk V, Voskoboynikov I, Schelokov V, Konstantinova S, Varnakov A (2014) Patent № 2511302 Russian Federation IPC A device for impregnating wood from an end face under pressure. Bull № 5 16. Shamaev V, Parinov D (2018) Patent 2646612 Russian Federation IPC B27 K 3/02 (2006.01) Wood treatment method. Applicant and patent holder Federal State Budgetary Educational Institution of Higher Education Voronezh State University of Forestry and Technologies named after G. F. Morozov.—№ 2017106989; appl. 02.03.2017; published, Bull № 7.—6. ill

Automated System for Monitoring the Upper Structure of the Railway Track for Extreme Arctic Conditions Daniil A. Loktev

and Alexey A. Loktev

Abstract In this paper, we consider the possibility of improving the system of monitoring and diagnostics of the railway track in difficult weather conditions, acting on the basis of the analysis of photographic images. The main task of the railway track monitoring system is to ensure safety, functional reliability of the track superstructure, as well as reduce the cost of its maintenance and reduce losses from downtime as a result of failures and premature repairs. An important aspect is the possibility of placing the main elements of the monitoring system on various land transport and technological complexes, and not only on specialized vehicles. This paper is devoted to the functioning of the software control and monitoring system, which allows you to obtain primary information about the object, classify it, identify and group external defects, compare their parameters with the established criteria and issue the processed information to the operator. The considered automated control and monitoring system can be attributed to systems with a continuous cycle. The paper proposes an effective approach for recognizing static and slow-moving objects based on the use of complex primitives, which are formed by constructing multilevel cascades of templates describing the image of an object in the direction of increasing accuracy. Also, to determine the characteristic points of an object, it is proposed a method, which is based on the displacement of an object in the overall picture using the frame framing the search pixel. Keywords Visible defects · Primary image · Blurring of the image · Railway track · Monitoring system

D. A. Loktev (B) Bauman Moscow State Technical University (BMSTU), 2-ya Baumanskaya 5, 105005 Moscow, Russia e-mail: [email protected] A. A. Loktev Russian University of Transport (MIIT), Chasovaya 22/2, 125190 Moscow, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_21

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1 Introduction The main task of the railway track monitoring system is to ensure safety, functional reliability of the track superstructure, as well as reduce the cost of its maintenance and reduce losses from downtime as a result of failures and premature repairs. An important aspect is the possibility of placing the main elements of the monitoring system on various land transport and technological complexes, and not only on specialized vehicles. Railway track diagnostics include the following main functions: assessment of the technical condition of the object; detection and localization of the fault; prediction of the residual resource of the object; monitoring of the technical condition of the object. The functioning of the diagnostic and monitoring system requires the presence and interrelation of three components: regulatory and technical documentation defining the functioning of the diagnostic system; technical means that provide control of the state of the track infrastructure; systems for collecting, storing and processing the received diagnostic information. This paper is devoted to the functioning of the software control and monitoring system, which allows you to obtain primary information about the object, classify it, identify and group external defects, compare their parameters with the established criteria and issue the processed information to the operator. The considered automated control and monitoring system can be attributed to systems with a continuous cycle.

2 Problem Statement The main stages of the program modules of the monitoring system can be represented by the following sequence of actions: activation of external modules for obtaining initial data, collecting information about the considered object, monitoring the process of obtaining initial data and the general state of the system, monitoring and controlling quality parameters, providing personnel and equipment with information necessary to start the monitoring process, establishing links between personnel and equipment, changing the parameters of video and photo recording of objects, depending on changes in environmental parameters or characteristics of the state or behavior of the object [1–3]. At the same time, the actual and timely task of developing a method that allows an integrated automated monitoring system not to depend on external parameters of the environment and the object itself and minimizing all possible changes in the composition and settings of standard photo and video recording systems taking into account difficult weather conditions (snowdrift, ice phenomena, etc.). Under recognition refers to the assignment of an object to a class of the selected classification. The proposed object recognition is to use a method of analysis of the

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image blur when classifying objects according to the distance to them, their velocity and the type of object [4, 5]. In the first approximation, when detecting defects, the surface points of the objects can be divided, depending on the distance from the video detectors, into “far” and “close”, and due to the motion of the measuring system under consideration (together with track-measuring cars) can be divided by speed—into “fast” and “slow”. The determination of the boundaries of the above groups is determined using the tools of statistical analysis and on the basis of fuzzy logic [4, 6] (Fig. 1). In the next approximation, it is possible to recognize an object by other characteristics (for example, by color components). The method of pattern recognition used in the work is based on the algorithm adaptive boosting (AdaBoost) [3, 7]. AdaBoost uses a weak classifier in a cycle, after each call the distribution of weights Dt is updated, corresponding to the importance of each of the objects of the training set. At each iteration, the weights of any incorrectly classified object increase and the new classifier minimizes the weighted classification error:

(a) far

k(y)

-8

(b)

k(v)

0

close

-6

-4

low

-2

0

y, m

high

1,5

3

4,5

6

v, m/s

Fig. 1 Boundaries of a the distance to the defect, b the speed of monitoring system

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h t = arg min ε j , εt = h j ∈H

m 

  Dt (i) yi = h j (xi ) ,

(1)

i=1

where εt —the weighted error of a classifier ht , if εt ≥ 0.5, then the execution of the algorithm is terminated. Then the resulting classifier is determined: H (x) = sign

 T 

 αt h t (x) ,

(2)

t=1 t . where αt = 21 ln 1−ε εt The expression for updating the distribution Dt must take into account the condition:  < 1, y(i) = h t (xi ) e−αt yi h t (xi ) (3) > 1, y(i) = h t (xi ).

Thus, after selecting the optimal classifier ht for the distribution Dt , the objects x i identified by the classifier ht correctly have weights smaller than the objects identified incorrectly. Therefore, when the algorithm tests classifiers on a distribution Dt+1 , it will choose a classifier that better identifies the objects incorrectly recognized by the previous classifier. For construction separate classifiers, Haar primitives are used [3, 8, 9].

3 Method of Solution The complexity of the primitives is as follows: one of the simplest primitives is overlaid with the reference image, then the sum of the pixel values in the white area of the primitive and the black area is calculated, and the second value is subtracted from the first value. The resulting value is a generalized characteristic of the anisotropy of the base area of the image N: N = Q w −Q bl ,

(4)

where Qw , Qbl —the total number of white and black pixels in primitives located in the selected image area. The implementation of the described procedure in full is associated with significant computational difficulties since even for a small image the number of primitives superimposed is very large (for an image 24 × 24 pixels, the number of primitives is about 180 thousand). The task of the adaptive boosting algorithm is to select those primitives that most effectively allocate this object, which will reduce the complexity and increase the final performance of the specified computational scheme [10, 11].

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Fig. 2 The use of primitives for basic image (defect—broken sleeper)

Figure 2 shows that for the object on the left, in the first stage, the algorithm chose a primitive with a horizontal black stripe. The primitives of this configuration and size “characterize” this image in the best way. Therefore, it is best to use just such a primitive to search broken along sleepers, varying by its size. On the basis of such classifiers with the selected most effective primitives, a cascade is constructed [5, 11, 12]. If the modules of the software and hardware monitoring system responsible for receiving and transmitting the primary image of the railway track elements move fast enough (at train speed), while processing the data in real-time, the algorithm using Haar primitives will not cope with the task of detecting and recognizing defects. Therefore, for such situations, the using a modified Lucas-Canada algorithm for pattern recognition by characteristic points is proposed [7, 8, 13]. At the stage of image preprocessing, the characteristic points of the image are selected and the optical flow in the vicinity of these points, which are the initial data for the object capture and tracking algorithm, is calculated [8, 14]. Optical flow is represented as an image of the visible movement of objects, surfaces or edges of the scene, resulting from the movement of the observer relative to the scene. In this case, the pixel of the image with the coordinates (x, y, t) in the plane and time and intensity I (x, y, t) for the duration of one frame received increments. The changed intensity of a pixel with small displacements can be represented as a segment of a row: I (x + x, y + y, t + t) = I (x, y, t) +

∂I ∂I ∂I x + y + t ∂x ∂y ∂t

(5)

Assuming that the intensity of the graphic point does not change for a small movement, and dividing this expression by t, it is possible to write the basic equation of the optical flow in the components of the velocity of the point in the direction of the main coordinate axes: Ix vx + I y v y + It = 0, where vx = x/t, v y = y/t, Ix = ∂ I /∂ x, I y = ∂ I /∂ y, It = ∂ I /∂t.

(6)

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Equation (6) must be resolved with respect to the unknowns ν x and ν y , this requires the use of additional conditions-restrictions. To calculate the optical flow of the image it is proposed to use the Lucas-Canada method [7, 14]. The process of determining the displacements of all pixels of an image has a large computational complexity, so it is often limited to determining the displacements of individual pixels, which is quite enough to determine the geometric and kinematic characteristics of objects that are low-deforming solids. As tracked pixels, it is proposed to select those whose color intensity differs significantly from the similar parameter of neighboring pixels, that is, the pixels located on the boundaries of objects are considered. The most informative are the pixels located at the joints of several borders, in the vicinity of such points the brightness of the image changes significantly when moving in several directions. To select the corner points, Harris Corner Detector uses a second-order moment matrix:  2 Ix (X ) Ix I y (X ) (7) A(X ) = w(X, σ ) ◦ Ix I y (X ) I y2 (X ) where—operation of taking two-dimensional convolution; I x (X)—image derivative in x direction about a pixel X; I y (X)—image derivative in y direction about a pixel X; w (X, σ )—weight function, which is used to average the brightness within the image area: w(X, σ ) = g(x, y, σ ) =



2 x + y2 1 exp − 2π σ 2 2σ 2

(8)

Matrix A describes the shape of the autocorrelation measure at the desired point in the image. This matrix for the corner point will have two large positive eigenvalues. In order not to calculate the eigenvalues λ1 and λ2 , to select the angular points, use the Harris parameter: R = det(A) − α trace2 (A) = λ1 λ2 − α(λ1 + λ2 )2

(9)

where α—some constant. Corner points are defined as local maxima of the Harris measure that exceed a given threshold h: {xc } = {xc |R(xc ) > R(xi ), ∀xi ∈ W (xc ) > h}

(10)

where W (x c )—the set of pixels around the desired pixel. The corner pixels of a selected Harris detector are invariant to rotation and illumination changes. In order for the proposed technique to be invariant to the considered scale, it is proposed to combine the corner detector with the Gaussian scale space [8, 15], the result is a Harris-Laplace detector [16], which assumes an automatic determination of the characteristic scale corresponding to the extremum of the objective function [17].

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4 Numerical Investigation Thus, the paper discusses the use of two variants of object recognition—the Adaptive Boosting algorithm using cascade classifiers with Haar primitives, and the algorithm of recognition by characteristic points. For each of them, the probabilities of errors of the first and second kind were determined depending on the ratio of the size of the boundaries of the object in the image to the size of the object (Fig. 3a, b), the speed of the object (Fig. 4a, b). From Figs. 3 and 4, it can be seen that for larger objects (more closely located) and for slower objects, the probability of errors of the first and second kind is less for the object recognition algorithm using the Haar primitives, while for all other objects the most appropriate is the use of using characteristic points. To reduce the probability of errors in object recognition, it is proposed to use the primary object recognition only by two parameters: distance from the camera and its speed. When defining an object in the class “slow” and “close”, an adaptive pattern recognition

(b)

P,%

P,%

(a)

Ratio of the border to the size

Ratio of the border to the size

Fig. 3 The dependence of the probability of error of the first (a) and second (b) kind of the ratio of the size of the boundaries of the object to the size of the object

(b)

P,%

P,%

(a)

Object speed, pix/frame

Object speed, pix/frame

Fig. 4 The dependence of the probability of error of the first (a) and second (b) kind of speed of the object

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algorithm is used, based on the use of cascade classifiers with Haar primitives. When defining an object in other possible classes, the feature point recognition algorithm is used.

5 Results As an object for testing the proposed algorithms and modules of the monitoring system, a railway overpass located on the Northern railway and sections at the entrance to it were chosen. A series of images on which the monitoring system revealed external defects of infrastructure elements were obtained. Defect 1 a staircase on the way to the overpass of reinforced concrete marches without a handrail, partially covered with rubble and overgrown with bushes (Fig. 5). Defect 2 a construction of old wooden sleepers and metal pins to prevent the ballast prism from falling off before the bridge abutment, the construction is actually made of improvised materials, the sidewalk actually ends with a breakage (Fig. 6). The found defects were determined with an accuracy of 86% at the speed of the monitoring system of 15 km/h, with an increase in speed the accuracy decreases. There is currently no ready-made analog of such a passive railway monitoring system using image analysis.

Fig. 5 The adjacent territory to the railway overpass, defect 1

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Fig. 6 The adjacent territory to the railway overpass, defect 2

6 Conclusion The paper proposes an effective approach for recognizing static and slow-moving objects based on the use of complex primitives, which are formed by constructing multilevel cascades of templates describing the image of an object in the direction of increasing accuracy. Also, to determine the characteristic points of an object, it is proposed a method, which is based on the displacement of an object in the overall picture using the frame framing the search pixel. Thus, the introduction of the method of the image blur analysis allows to find external defects of the rail grille and to determine its operational condition. Acknowledgements This work was supported by the Ministry of Education and Science of the Russian Federation R&D State project № 2.5048.2017/8.9.

References 1. Beder Chr, Bartczak B, Koch R (2007) A comparison of PMD-cameras and stereo-vision for the task of surface reconstruction using Patchlets. In: Computer vision and pattern recognition, IEEE. pp 1–8 2. Swadzba AA (2006) Estimation of camera motion from depth image sequences. Diplomarbeit im Fach Informatik 108 3. Langmann B, Hartmann K, Loffeld O (2012) Depth camera technology comparison and performance evaluation. In: Proceedings of the 1st international conference on pattern recognition applications and methods, pp 438–444

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4. Schiller I, Beder Ch, Koch R (2008) Calibration of a PMD-camera using a planar calibration pattern together with a multi-camera setup. In: Proceedings of ISPRS archives, Beijing, China; XXXVII, part B5, pp 297–302 5. Deschenes F, Ziou D, Fuchs P (2000) Enhanced depth from defocus estimation: tolerance to spatial displacements. Rapport technique, no. 256, Université de Sherbrooke, Sherbrooke, Qc, Canada, pp 34–42 6. Borachi G, Caglioti V (2008) Motion blur estimation at corners. In: Computer vision theory and applications VISAPP, pp 389–395 7. Lucas BD, Kanade T (1981) An iterative image registration technique with an application to stereo vision. In: Proceedings of imaging understanding workshop, pp 121–130 8. Chu CW, Hwang S, Jung SK (2001) Calibration-free approach to 3-D reconstruction using light stripe projections on a cube frame. In: Proceeding of IEEE 3rd International conference on 3-D digital imaging and modeling, Quebec City, QC, Canada, pp 13–19 9. Loktev AA, Izotov KA, Loktev DA (2018) The possibility of increasing the bandwidth of fiberoptic communication lines. In: Proceeding: Moscow workshop on electronic and networking technologies, MWENT 2018—Proceedings 1, pp 1–4 10. Loktev AA, Sychev VP, Buchkin VA, Bykov YA, Andreichicov AV, Stepanov RN (2017) Determination of the pressure between the wheel of the moving railcar and rails subject to the defects. In: Proceedings of the 2017 international conference “quality management, transport and information security, information technologies”, IT and QM and IS 2017, pp 748–751 11. Loktev D, Stepanov R, Loktev A, Pevzner V, Alenov K (2018) An aggregated method for determining railway defects and obstacle parameters. IOP conference series: materials science and engineering 4. “4th international conference on advanced engineering and technology, ICAET 2017”, pp 012–021 12. Loktev A, Sychev V, Gluzberg B, Gridasova E (2017) Modeling the dynamic behavior of railway track taking into account the occurrence of defects in the system wheel-rail. In: Proceeding MATEC web of conferences 26. “RSP 2017—26th R-S-P seminar 2017 theoretical foundation of civil engineering”, p 00108 13. Loktev DA, Loktev AA (2016) Estimation of measurement of distance to the object by analyzing the blur of its image series. In: Proceeding: 2016 international Siberian conference on control and communications, SIBCON 2016, p 7491683 14. Loktev DA, Loktev AA (2015) Development of a user interface for an integrated system of video monitoring based on ontologies. Contemp Eng Sci 8(20): 789–797 15. Loktev DA, Loktev AA (2015) Determination of object location by analyzing the image blur. Contemp Eng Sci 8(9):467–475 16. Loktev AA, Gridasova EA, Kramchaninov VV, Stepanov RN (2015) The method of determining the locations of reinforcing elements in a composite orthotropic plate undergoing dynamic impact. Part 2. Calculation algorithm. Appl Math Sci 9(69–72):3541–3547 17. Loktev AA (2012) Non-elastic models of interaction of an impactor and an Uflyand-Mindlin plate. Int J Eng Sci 50(1):46–55

Traffic Management System for the Northern Latitudinal Railway Efim N. Rozenberg, V. I. Umansky and M. I. Shmulevich

Abstract Currently, JSC NIIAS is developing the train control system “Anaconda” for the Northern Latitudinal Route where the railway tracks and infrastructure are located in the permafrost conditions with low population density. Therefore, the equipment of the control system is installed at stations and onboard rolling stock, and it is based on the minimally manned operation. “Anaconda” is the train separation system where train positioning is based on remote acoustic sensing of railway tracks along which vibroacoustic fiber optic cable is laid. A cable receives signals, which are partially reflected from inhomogeneous structure of the fiber optic cable. The light-sensitive detector receives the reflected signals. As a result of cable mechanical vibration caused by the rolling stock, there is the change of reflected signals that is registered by the detector. The system monitors the rolling stocks location with an accuracy of up to 10 m at a distance of up to 40 km from transreceiver. Vibroacoustic fiber optic cable along with train positioning allows broken rail detection, obstacles and staff detection on railway tracks. The equipment of the “Anaconda” system has been successfully tested and was put into trial operation on the Moscow and Kaliningrad railways. Keywords Minimally manned operation · Train separation system · Acoustic sensing of railway tracks · Vibroacoustic cable The construction of the Northern Latitudinal Railway (NLR) is one of the projects contributing to the development of the Artic region of the Russian Federation. The project is to create an East–West route connecting the Northern and Sverdlovsk Railways as part of the integrated Arctic transportation system and infrastructure that enables the development of the natural resources of the Russian Arctic region on land and offshore. E. N. Rozenberg (B) · V. I. Umansky JSC NIIAS, bldg 1, 27 Nizhegorodskaya str., 109029 Moscow, Russia e-mail: [email protected] M. I. Shmulevich CJSC PROMTRANSNIIPROEKT, 29 Vernadskogo pr., 119331 Moscow, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_22

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Additionally, the NLR will reduce the distance between the natural resource deposits in the northern regions of Western Siberia to the ports of the Baltic, North, Barents and Kara seas. The Russian Government identified NLR as a priority project serving the regional and national development. The latter is associated with the following goals: – dynamic growth of the Russian economy, social development, and strengthening of relations between regions, as well as elimination of territorial and structural disparities in the transportation system, – inclusion of new territories into economic activities by means of additional transport links, – growth of business activities and entrepreneurship that directly improve the living standards, – creation of infrastructures for targeted support of economic growth, including comprehensive development of new territories and deposits of commercial minerals, – ensuring the availability, sufficiency, and competitiveness of railway transportation services in terms of freight owners’ expectations, – improvement of the availability and quality of railway transportation services to the general public in terms of social standards. Within the framework of the Russian Railway Industry Development Strategy the project’s implementation will have the following effects: – construction of new freight-generating and service railway lines as part of the Ural Industrial—Ural Polar project, the Northern Latitudinal Railway being its main infrastructure component, – improved transportation service of the new areas of economic growth, – creation of direct railway access from the industrially developed Ural to the natural reserves of the Yamal peninsula under development. The project involves both the construction of new and overhaul (improvement and completion) of existing lines and stations that are now at various stages of completion. Thus, the railway infrastructure facilities of the Konosha–Kotlas–Chum–Labytnangi line of the Northern Railway are to be overhauled to enable freight traffic coming from the NLR into the JSC RZD infrastructure. The Obskaya station is also to be further developed to allow integration with new infrastructure facilities, i.e. the combined road-rail bridge over the Ob river near Salekhard, including the approaching railway line. Along with the Ob river bridge, a crossing over the Nadym river is to be constructed as well (Fig. 1). The new 353-km Salekhard–Nadym line is to be constructed from the ground up. The earlier started construction of the Novy Urengoy–Nadym (Khorey) line will continue. In the newly constructed sections, NLR’s carrying capacity will reach 23.9 mln tn per year, while its traffic capacity will be as high as 20 pairs of trains per day. In order to enable those figures, crossing loops will be put in place on both the existing and the newly constructed line sections.

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Fig. 1 Diagram of the NLR sections

The traffic management system (TMS) for the NLR is to be developed subject to the target volume of traffic, as well as the harsh climate conditions (low temperatures, deep soil frost, etc.) and sparse population of the region. In the development of TMS structure, the experience of signalling systems application in the cold climate conditions both in Russia and abroad–Western Europe, the USA, and Canada [1], Japan [2, 3] and China [4–6] was used. Generally, the main technical solutions are related to the concentration of the equipment at the stations that allow reducing requirements for the equipment and simplifying the conditions for its maintenance. In Russia, such solutions include centralized automatic block signalling (ABTC, ABTC-M, ABTC-MSh), and abroad, these are European Train Control System ETCS and Chinese Train Control System (CTCS). At the same time, the existing TMS systems either include track circuits that are “weak component” for such extreme operation conditions (ETCS Level 2, CTCS Level 2 and Level 3), or rely on information received via radio channel (ETCS Level 3 and CTCS Level 4), that is not always able to guarantee the reliability of TMS operation. This, in particular, explains the fact that the last of the mentioned systems have not yet been widespread. The train separation system “Anaconda” considered below applies the vibroacoustic monitoring method, which allows the complete exclusion of track circuits at the open lines and in combination with a radio channel improvement of TMS operation reliability. TMS should be based on the latest achievements in the field of microprocessor and information technologies, including satellite [7–11]. TMS is divided into three levels (Fig. 2). The top-level is the centralized traffic control facility (CTC) that collects and displays the information on the current situation on the line, i.e. position of all trains (coordinates), their movement direction and speed. The CTC can be implemented based on the Dialog computer-based system. The intermediate level (at the line’s stations) includes computer-based interlocking (IXL), e.g. Ebilock-950 system that enables the supervision of the operational situation at stations, crossing loops and adjacent open lines, as well as route control and train handling. The lower level represents the onboard train protection equipment that receives information and commands from station-based units and generates own executive commands.

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CTC

IXL

RC

RC

RC

IXL

ANACONDA

ANACONDA

Fiber optic cable

Fig. 2 NLR traffic control system architecture

It is proposed to equip trains with vital onboard systems (KLUB-U or BLOK) that include radio communication equipment for information exchange (including train coordinates) with the station-based assets and CTC. Train supervision and separation in open lines is suggested to be implemented using the Anaconda system, a new development by JSC NIIAS. The Anaconda train separation system (TSS) enables: – supervision of occupancy/vacancy of open line sections and monitoring of train traffic using vibroacoustic sensing (with no track circuits), the track being divided into 100-m long virtual sections, – automatic identification of the types of onboard train protection units of all traction units within the system’s range, – departure of trains equipped with vital onboard units per permissive exit signal if one or more departure sections are vacant, – train separation (where trains are equipped with vital onboard units) at open lines with moving block sections and automatic cab signalling, – departure of trains not equipped with vital onboard units per permissive exit signal only if open line is completely vacant, – transmission of information on the operational situation (distance to the preceding train) to trains via radio channel units (RC), – transmission of train identification information via a radio channel to the station. In the Anaconda TSS, information communication between station-based and onboard devices is based on the use of a digital radio channel whose components are installed at stations and open lines to ensure radio coverage, as well as onboard the trains. The system is compatible with various types of digital radio equipment, e.g. 160 MHz, DMR, GSM-R, TETRA, etc. Anaconda equipment is located in relay rooms of interlocking stations and portable modules. A single Anaconda system ensures supervision of up to 40 km of track.

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y

tra in

rit ho

ic

ta

tif

ut

en

on

IXL

Id

M ov

n

em

io

en

at

at io n

n

In fo rm

Authority for clearing of cab signalling signal

ai

Train integrity based on pressure in main brake line

ANACONDA Tr

in te gr ity

RC

Down2 Down1

Down

Fiber optic cable

Up

Train Identification

Logical train traffic control on running track

Fig. 3 Operation of the Anaconda TSS in station

As the distributed vibroacoustic sensor, the system uses a fiber-optic acoustic sensor (FOAS), i.e. a fiber-optic cable laid along the track section supervised by the system. The FOAS is installed within the roadbed subject to the following requirements: – the FOAS cable track in the area of the receiving and departure tracks and yard necks is to be designed subject to the local conditions, – the FAOS cable track at stations in the area of approaches from adjacent open lines and at the open lines is to be designed in such a way that cable lays within the roadbed at a distance of 3–10 m from the track centerline in the horizontal plane, – the depth of cable laying shall be at least the depth of soil freezing for the specific territory, – the ordinates of the insulated joints of entrance and warning signals, as well as the ends of passenger platforms in open lines shall have FOAS cable loops not shorter than 10 m to be used as the markers for more accurate rolling stock positioning. The Anaconda system includes the so-called “optical platform”. This module’s generator creates an acoustic signal that is continuously supplied into the FOAS, while the module’s receiver analyzes the response. In the process, the “acoustic portrait” of the train in the open line is created, i.e. the train’s location and linear dimensions are identified. Trains equipped with vital on-board units transmit train integrity information via the radio channel based on the level of pressure in the brake line. Anaconda equipment at the departure station supervises a train’s positioning within the open line and can give movement authority for the departure of the next train if its locomotive is equipped with a vital onboard unit (Fig. 3). While the train is at the station, preliminary identification is performed. The IXL equipment sends alternating yellow-red safety code signals to the track circuits (those are absent only in open lines). If on this circuit there is a train equipped with a vital onboard unit, it further transmits the received code signal to the station-based Anaconda equipment via the radio channel. Having received from the vital onboard unit the information of a locomotive being on the track, Anaconda, using the IXL system, generates the clear

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exit signal, so the train will be dispatched into the open line following the previous train if the distance between them is safe. If a train at the station does not identify itself as one equipped with a vital onboard unit, the permissive signal for its departure will be generated only upon the arrival of the previous train to the next station. A satellite navigation system (GLONASS or GPS) allows identifying the coordinates of the train’s head in open lines. This information along with the data on train integrity is transmitted to the Anaconda station-based equipment via the radio channel. Using this data, the Anaconda trackside equipment identifies which virtual sections of the open line are vacant before each train. This information is individually transmitted to each train via the radio channel. Its vital onboard unit compares the received information with the electronic map data and its own location identified by the satellite navigation system. The vital onboard unit calculates the allowed speed and displays it on the driver-machine interface, while the vital onboard unit supervises the observance of the speed limit by the driver. Feasibility studies have shown that the proposed train separation system based on remote vibroacoustic sensing of railway tracks will reduce capital expenditures for the equipment of the Northern Latitudinal Railway three times while cutting TMS life cycle cost by 20%. The Anaconda TSS has been successfully tested and put into trial operation at the Moscow (Bolshevo—Fryazino line) and Kaliningrad (Shipovka—Baltiysk line) railways. Innovative technical solutions have been patented.

References 1. Teega G, Vlasenko S (2010) Signalling systems of the world railways. Intekst, Moscow 2. Igarashi T, Aoyagi M, Ubukata R, Amiya N, Tobita Y (2010) Automatic train control system for the Shinkansen utilizing digital train radio. WIT Trans State Art Sci Eng 46:27–35 3. Kotake H, Matsuzawa T, Shimura S, Haruyama S (2010) A new ground-to-train communication system using free-space optics technology. WIT Trans State Art Sci Eng 46:683–692 4. Ning B, Tang T, Qiu K, Cao C, Wang Q (2010) CTCS—Chinese train control system. WIT Trans State Art Sci Eng 46:1–8 5. Bin N, Tao T, Min QK (2010) CBTC: system and development. WIT Trans State Art Sci Eng 46:37–44 6. Wei C, Liu S, Lai C, Chung WH (2010) A fibre Bragg grating sensor system for train axle counting. IEEE Sens J 10(12):1905–1912 7. Rosenberger M (2011) Die Herausforderungen an Raddetektion und Achszalung in der Zukunft – Teil 1, Signal + Draht (103), 6–12 (9/2011) 8. Grunding G (2011) Die Herausforderungen an Raddetektion und Achszalung in der Zukunft – Teil 2, Signal + Draht (103), 32–38 (12/2011) 9. Rosenberger M, Pucher C (2012) Das Achszalsystem FAdC bietet Vorteile fur Stellwerksintegratoren und Betreiber, Signal + Draht (104), 27–32 (4/2012) 10. Barbu G, Hanis G, Kaiser F (2014) SATLOC – GNSS gestutzte Zugsicherung fur Strecken mit niedriger Verkehrsdichte, Signal + Draht (106), 39–44 (4/2014) 11. Fitzek F, Fettweis G, Stoll J (2016) 5G ermoglicht Bahn 4.0 ETR (1 + 2/2016), 10–14

Rails for Low Operating Temperature and High Speed Evgeny Shur, Alexey Borts and Sergey Zakharov

Abstract The operation of railways in cold regions places high demands on rails. This paper summarizes the Russian Railways experience and studies of the probability of rail breaks at low temperature. Test methods and standards for rails designed for low-temperature operation have been developed. These include rail toughness, low-temperature drop tests, fracture toughness under static (KIC ) and cyclic loading of full-profile rail samples (Kfc ). A production technology and technical conditions for thermally hardened rails have been developed, which can ensure their reliable operation at low temperatures and high speeds. Values of impact toughness at low temperature (KCU at −60 °C > 25 J/cm2 ) and low-temperature drop strength (the work of destruction more than 90,000 Nm of full-profile rail samples at a temperature of −60 °C) is provided by the fine-grained structure of rail steel. It is achieved by obtaining vanadium carbonatites due to the increased content of vanadium (0.05– 0.15%) and nitrogen (0.008–0.020%), as well as thermal treatment. To prevent the occurrence of rail breaks rail flaw detection is of great importance. High-speed train operation in cold regions is disadvantaged by increased crashing of rails in welds heat-affected zones which cannot be eliminated by local heat treatment. Only fundamental changes in the production technology of welded 800 m rail strings, when induction heat treatment is performed after welding, allows reducing the softened zone length to 4–6 mm and solving the problem of rail straightness during the entire period of its operation. Keywords Rails · Low temperature · Rail failure · Mechanical properties · Drop tests · Heat treatment

E. Shur · A. Borts · S. Zakharov (B) SC “Railway Research Institute”, Moscow, Russia e-mail: [email protected] E. Shur e-mail: [email protected] A. Borts e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_23

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1 Introduction The Russian Railways are located in the coldest climates compared to many railways in the world. This creates extreme operating conditions for them and threatens traffic safety. About 70% of Russian territory is located in zones of a cold and very cold climate [1]. Three large railways (Zabaykalskaya, East-Siberian, and Sverdlovskaya) are located in the zones where the number of days per year with an average daily air temperature below −30 °C is more than twenty. There are several other railways (Far Eastern, West Siberian, South Ural, Northern), which are located in a zone of moderately cold climate, where the number of days per year with air temperatures below −30 °C is more than five. The planned railway construction in the northern regions of Russia will further increase the share of railroads that are operating under extreme conditions. Low temperatures significantly change operating conditions of the rails and track, primarily due to the increased track stiffness and because of its influence on rails mechanical properties [2]. This paper discusses the results of studies on changes in the properties of rail steel and rails with decreasing temperature, the effect of temperature on their failure rate in operation, as well as an experience in the production of the “northern version” of rails.

2 Effect of Operating Temperatures on Properties of Rail Steel and Rails 2.1 Impact Strength Numerous tests of various perlite-grade rail steels on impact strength, which are usually carried out on pendulum machine with specimens 10 × 10 × 55 mm in size, notch 2 mm deep and relatively small 1 mm radius, showed that in the temperature range of rail operation (from −60 to +50 °C) there is a smooth decrease in toughness with a decrease in temperature. As with all high carbon content steels, there is no sharp drop in toughness at any temperature, so it is not possible to determine the temperature of a viscous-brittle transition directly from the temperature dependences of toughness. The widespread method for determining the temperature of a viscous-brittle transition by the 50% of the viscous component in the fracture, reflecting the change of mechanisms of destruction, does not help in this case either. Conducting a series of temperature impact strength tests with determining the temperature of the viscous-brittle transition (T 50 ) by the type of fracture, showed that for samples cut from differentially heat treated (DT350) rails, it was more than 200 °C. Thus, the temperature of the viscous-brittle transition for pearlite rail steels is much higher than operating temperatures. That is why the separation of toughness (an ) into components of crack origination and development (a3 and ap ) within the limits of operating temperatures does not make sense, since crack development work (ap ) differs little from zero. In this case, the use of the “temperature viscosity margin” concept T = T  − T K , as a difference between the operating temperature and the

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critical temperature, proposed by N. N. Davidenkov, loses its physical meaning, since the operating temperature is less then critical. Formal use in calculations a negative temperature margin of viscosity [3] is somehow justified at close values of the operating and the critical temperatures‚ but it becomes not possible when the difference between them became, as in rail steel, 150–300 °C. In this case, as it often turns out that a material having a lower viscous-brittle transition temperature, but also significantly exceeding the working temperature range, has not more, but less energy intensity at operating temperatures. Therefore, for rail steels the viscous-brittle transition temperature T 50 of which substantially exceeds the operating temperature, the viscous-brittle transition temperature as a parameter to estimate the resistance to brittle fracture cannot be used. Resent tests to determine the impact toughness of rail grades OT 350 (T1), OT 350 NN (NK, NE), DT370IK, DT350, DT350NN at temperatures of −30, −40, − 50 and −60 °C showed (Fig. 1) that the highest impact toughness of 35–38 J/cm2 have OT350NN rails for low-temperature, thermally hardened by quenching in oil from a separate furnace heating. This is because of the use of nitrogen and vanadium as alloying elements, which are carbon-nitride-forming elements as well as recrystallization process during reheating for quenching. Both of these factors reduce the grain size, which increases the impact strength. It should be noted that with a decrease in temperature from −30 to −60 °C, the impact toughness of OT350NN rails actually does not change. In the rails of the other categories, the following decrease in impact toughness is observed: – for rail OT 350 (T1): from 28.0 to 17.0 J/cm2 —by 39%; – for DT 350 rails: from 21.0 to 17.0 J/cm2 —by 19%; OT350( T1)

OT350NN

DT350

DT350NN

DT350IK

40

IMPACT THOUGHNESS , KCU, J/CM2

35 30 25 20 15 10 5

-70

-60

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temperature, 0C

Fig. 1 Dependence of impact toughness on temperature

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– for DT 350NN rails: from 27.0 to 18.0 J/cm2 —by 19%; – for DT370IK rails: from 14.0 to 9.0 J/cm2 —by 36%. The most significant reduction in toughness is observed in the OT350 (T1) and DT370IK categories of rails.

2.2 Static Fracture Toughness (Fracture Viscosity) Fracture viscosity is the second indicator of the resistance to fracture of rail steels. Its advantages over toughness lies in the fact that it cannot only make a comparison of materials, but also permits to calculate the resistance of rails to brittle fracture. Therefore, the critical value of the stress intensity factor (K IC ) currently occupies the main place in the series of parameters for assessing the resistance to brittle fracture of rail steels and has been introduced into the latest rail standards [3, 4]. The fracture toughness K IC was determined by bending samples, in which a fatigue crack of a certain length was grown from a sharp incision made by mechanical means. This test method complies with the national standard [4]. In addition, the fracture toughness of full-profile rails K fc was determined by the magnitude of the semicircle of a fatigue crack of a critical value, which was broken during cyclic fatigue tests of the head in the tensile zone. With a decrease in temperature, a gradual decrease in the fracture toughness occurs (Fig. 2). At temperatures below −30 °C, the curves flatten out. 40 39 38 37 36 35

KIC, MPa m1/

2

34 33 32 31 30 29 28 27 26 25 24

R350HT

23 22

R260

21 20

-100

-80

-60

-40

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0

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temperature, 0C

Fig. 2 Temperature-dependent fracture viscosity for rails R350HT and R260. Source Proceedings of IHHA-2011, E.A.Shur, fin 00152

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Table 1 Static fracture toughness of rail grades at temperature from −30 to −60 °C Rail grade

Test sample temperature range (°C)

K IC (MPa m1/2 )

Average K IC (MPa m1/2 )

Standard deviation (MPa m1/2 )

OT350 (T1)

From −30 to −60 °C

From 41.7 to 45.1

43.3

1.5

OT359HH(HK)

From 40.7 to 48.3

43.8

3.1

DT350

From 32.2 to 37.8

34.6

2.0

DT350HH

From 35.2 to 37.4

36.0

0.8

DT370IK

From 34.7 to 37.1

35.9

1.0

Special tests to determine K IS of various rail grades in the temperature range from −30 to −60 °C (Table 1) showed that for all rail grades studied the K IC in that temperature range do not actually change.

2.3 Fatigue Resistance of Rails Fatigue resistance of rails was assessed by conducting tests of full-profile rail samples at different temperatures. Tests were carried out on a pulsator-testing machine of 400 cycles per minute frequency and an asymmetry factor of 0.1. Rail, support and punch were placed in a low-temperature chamber which was mounted on the lower traverse of the testing machine. Cold air was supplied to the chamber from the turborefrigerating machine, which made it possible to maintain the required temperature in the range from +20 to −100 °C during the entire test time with an accuracy of ±5 °C. For each temperature tests based on 2 million cycles were carried out, fatigue curves were build and measured the area of fatigue cracks in broken rails. These unique tests gave interesting results. The limit of rails endurance increased by 11% with change of temperature from +20 to −60 °C which is associated with rise in the strength of rail steel at negative temperatures. The sensitivity to stress concentration of rails at low temperatures increases significantly. The brittle failure of rails at low temperatures comes from fatigue cracks, the size of which is significantly smaller than that of similar fatigue cracks at room temperature (Fig. 3). For the purpose of studying the effect of low temperatures on fatigue cracks growth in rail steel, it is useful to consider kinetic crack growth diagrams obtained on standard samples with a notch of rail grade OT 350 (T1) at temperatures from +20 to −60 °C (Fig. 4).

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vertical crack size, mm

30 25 20 15 10 5 -80

-60

-40

0

-20

0

20

temperature, о С

crack growth rate,lg(dL/dN) x 10-9,mm/cycle

Fig. 3 Dependence of the critical crack size from temperature obtained from analysis of cracks in rails broken in railway operation

1/2

Stress intensity factor, ΔK, MPa ∙ m

Fig. 4 Kinetic diagram of fatigue failure of T1 grade rails at temperatures +20 and −60 °C

As a result of graphs power approximation in Fig. 4, the equations describing the patterns of crack length (L) growth at the main √ stage of their development, as well √ as the maximum threshold √ (K th = 16 MPa · m) and critical K IC (48 MPa · m for + 20 °C and 36 MPa · m for −60 °C) were found. The Paris equations and coefficients C and m for temperature +20 °C are: dL/dN = 16.894K 2.718 , where C = 16.894 and m = 2.718.

(1)

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For temperature −60 °C corresponding Paris equation: dL/dN = 3.8058 K 3.3157 ,

(2)

where C = 3.8058 and m = 3.3157. Comparison of crack sizes in tested samples showed that the critical size of the √ fatigue crack at K = 24.0 MPa · m is 27 mm at a temperature +20 °C and 21 mm for temperature −60 °C. A decrease in temperature leads to a decrease in the critical crack size by 22% √ with the same value of K = 24.0 MPa · m, as well as to a decrease in the critical coefficient and stress intensity factor by 25%. At the same time, at the initial stages of crack development where the values of stress intensity factors are close to K th , the rate of crack development in the rail steel at positive temperatures is even slightly higher than at negative temperatures, which is associated with the effect of increasing strength properties at lower temperatures. Thus, low temperatures are most dangerous when exposed to high loads on the rails or when there are already existing cracks whose dimensions are close to critical. Both of these factors contribute to an increase in the value of the stress intensity factor, bringing it closer to the critical and accordingly to the rail break.

2.4 Drop Weight Rail Resistance Drop strength of rails is determined in tests of rail samples for impact bending, which are made on the vertical 1000 kg drop weight machine [5]. The rail sample 1.3 m in length is placed head up or down on two pillars installed at a distance of 1.0 m. Testing a series of identical samples determine the destruction work of rails upon impact. The height of the load gradually decreases until the samples cease to collapse. The minimum impact work at which the destruction of samples occurs corresponds to the work of their destruction. The work of destruction of the rail sample can also be determined using special equipment which is used to find the speed of weight movement before and after the collision with the rail sample. Field tests of rail samples for impact bending are carried out at different temperatures, thus determining the cold brittleness of rails. Like impact toughness, the work of destruction of full-profile rails gradually decreases with decreasing temperature (see Fig. 2). And for full-profile rails the destruction work over the entire temperature range remains significantly higher than the work of destruction of welded joints.

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2.5 Drop Weight Bench Tests Drop weight bench tests of OT 350 (T1), OT 350 NN (NK, NE), DT370IK, DT350, DT350NN rail grades were carried out at set temperatures according to the state standard GOST P 51685-2013. Full profiled rail samples of 1300 mm in length, pre-cooled in MTK-240SK refrigeration chamber to temperatures −30 and −60 °C were placed head up on the supports of a vertical drop weight test machine (Fig. 5). The distance between supports was 1000 ± 5 mm [6]. The purpose of these tests was to find the rails destruction work as well as impact plasticity. Weight of 1000 ± 3 kg was lifted to different heights and dropped on the rail. After the dynamic impact in the absence of rail break the deflection was measured and the dynamic load was increased by raising the height of the load by 1.0 m and so on until the rail break. In the case when the lifting height of the load reached the highest value of 10.0 m and the rail did not break, a repeated dynamic action was taken until the rail was broken. Figure 6 shows graphs of rails deflection as a function of the dynamic impact energy magnitude, defined as F dyn = m g h, where m is the weigh mass, g is the acceleration of gravity, h is the height of the load. Inclined parts of the curves shown in Fig. 4 illustrate the dependence of the residual deflection of the rails on the dynamic impact energy, which increases with increasing height of dropped load. The vertical parts of the curves shown in Fig. 6 correspond to the fracture of rail samples. A linear approximation of graphs sloping parts allows to determine the Fig. 5 Drop weight machine

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dynamic impact energy at which the rail does not bend. For all tested rails these values are below 50.0 kJ. The highest energy destruction was obtained on rail grade OT350NN hardened from reheating and OT350. The rails hardened from as rolling heating DT350NN, DT350 and DT370IK categories had lower destruction energy.

2.6 Systematic Monitoring of Rails Failures Study of broken rails play an important role in improving reliability of rails and traffic safety. Of great importance is the investigation of the ambient temperature influence on rail fracture. Since to obtain sufficient data from a number of broken rails in one year is not possible, 10 years analysis of broken rails on the Russian Railways was carried out. Figure 7 shows the actual data of recorded temperatures at which rail brakes occurred and Fig. 8 the dependence of the rail failure relative probability on the ambient air temperature. It is evident that an increase in the number of rail brakes with a decrease in the ambient temperature has a physical background and it is associated with a drop in resistance to brittle fracture and an increase in the rigidity of railway track in winter. The reduction in the number of rail brakes with a further decrease in temperature to less than −30 °C is associated with lesser probability of such frosts on the Russian Railways network. In order to quantify these probabilities a matrix of the number of days was compiled in absolute and relative terms with a temperature in a certain interval on various

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number of rail failures for 10 years

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Fig. 7 Dependence of a number of rail failures from ambient temperature: 1—less −30 °C; 2— from −20 °C to −29 °C; 3—from 0 to −19 °C; 4—from +1 to +10 °C; 5—from +11 to +20 °C; 6—more +21 °C

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railways of Russia. Some railways were divided into two parts for climatic reasons. By multiplying the corresponding number of days by the length of the railway, summing and dividing by the length of the entire Russian Railways network, indicators were obtained, into which the numbers of rail failures in the corresponding temperature intervals were divided. Thus, relative fracture probabilities with decreasing temperature were calculated. It turned out that the probability of rail failures at the temperature interval from −20 to −30 °C increases by 13 times as compared to temperatures above +10 °C.

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3 Conclusion and Further Work 3.1 Conclusion To solve the most important issues of railway operation at low temperatures, such as setting maximum train speeds, adjusting the limits of tolerances, etc., calculations are needed based on knowledge of the patterns of changes in properties of all track elements and first of all the rails. In the described study, the dependences of all basic rail properties on temperature were obtained. The properties of low-temperature reliability (HH) rail categories were presented and ways to further increase of the welded track resistance at low ambient temperature was outlined.

3.2 Prospects of Increasing Rails Resistance to Failure at Low Temperature The results of above-described studies of the properties of rails at low temperatures and the experience of their operation at Russian Railways indicate that rails hardened from rolling heating, even category NN, are not enough to provide the necessary train safety at low and extremely low temperatures. The problem is further complicated by the fact that the inevitable softened zones near the welded joints, subjected and not subjected to subsequent local heat treatment, leads to the formation of local recess (“saddles”) in these places. As a result, dynamic overloads increase, leading to fatigue damage to the rails base and rolling stock components. The way out of this situation can be the development of differentiated heat treatment with a separate induction heating [7, 8]. At the same time the rail strings of 800 m in length should be subjected to heat treatment, which eliminates the formation of “saddles” in the welded joints. The implementation of this production technology does not require restructuring of the entire track management system, since the transportation of 800-meter-long strings will be carried out using the existing rolling stock. Acknowledgements This study was carried out as a part of the “Russian fond of fundamental studies (RFFS)—Russian Railways (JSC “RZD”)” project No. 17-20-01147 “Developing an integrated scientific approach to the study and prediction of the performance and life of new generation of rails under heavy haul operation and increased axle loads”.

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References 1. Zakharov SM (2011) The influence of seasonal climatic variation on wheel/rail performance: experience, causes and study. In: Proceedings of IHHA-STS conference, Calgary, Canada, fin00101 2. Ladubek K, Magel E (2011) Winter railroading in Canada. A review of track and rolling stock challenges. In: Proceedings of IHHA-STS conference, Calgary, Canada fin 00244 3. Shur EA (2011) Rails for operation at low temperatures. In: Proceedings of the international heavy Haul association conference, Calgary, Canada, fin 00152 4. Shur EA (2012) Rails damages. Intext, Moscow 5. Reykhard VA (1992) About reliability of rails at low temperature. Vestnik VNIIZhT, № 7. 7–11 6. Shakhov VI, Diakonov VN, Reykhard VA (1989) Kaportzev: influence of low temperatures on rails fatigue resistance.Vestnik VNIIZhT, 1:47–50 7. Khlyst SV, KysmichenkoVM, Resanov VA, Bortz AI, Shur EA (2013) Advanced manufacturing technology of rails for high speed and heavy Haul operation, Vestnik VNIIZhT, 6:14–17 8. Guidelines to Best Practices For Heavy Haul Operations (2015) Maintenance of the wheel and rail interface, IHHA, Simmons Bardman Books, USA, pp 4–21

Complex Solutions for Providing Roadbed Stability on Permafrost Svetlana Zhdanova

and Oksana Neratova

Abstract The paper gives examples of determining the causes of roadbed deformations and its strengthening on the Baikal-Amur Mainline and Amur-Yakutsk Mainline, the Berkakit–Tommot section. The main principles determining the construction in permafrost areas are, on the one hand, low capital and running costs of an immediate normalization of engineering and geological processes (those of the frozen ground first of all) in the bases of natural and man-made systems (earth structures—roads), and on the other hand, an adherence to a balanced thermoregulation of developed areas within their landscapes. The goals of all conservation and anti-deformation measures that provide a stability of natural and man-made systems are achieving high strength characteristics of the roadbed soils and its subgrade in shortest time and providing the longest period of their service. Keywords Permafrost · Anti-deformation measures · Water encroachment into areas · Freight traffic · Cryogenic deformations · Complex technological design solutions

1 Introduction The paper covers some issues of long-term maintenance of railroads and their roadbeds on permafrost in complex natural and climatic conditions including the frozen ground ones in the south-eastern part of the Russian Far East. The “roadbedpermafrost” natural/man-made system experiences considerable changes because of the outer and in-system processes during its long-term exploitation.

S. Zhdanova (B) · O. Neratova Far East State Transport University, 47, Serysheva, Khabarovsk, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_24

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An unforced self-restoring process in the “man-made/natural” system on permafrost takes a considerable time, namely 15–18 years and more, with the operational and environmental conditions remaining the same [1]. However, it is quite different when external factors influence the process. According to the researches of Zabaikalye in 70–80s of the previous century and of the Easter Section of the Baikal-Amur Mainline in the first decade of this century carried out by the engineers of the Substructures and Foundation Lab (the Far Eastern State Transport University, Khabarovsk), the most important factors producing an impact on the roadbed stability are traffic conditions, an increasing density of freight traffic and maintenance works [2]. Besides, malfunctions in the drainage system, problems of the roadbed maintenance and an impact of other infrastructure facilities on the common roadbed as well as a commercialization of natural resources (wood-felling, for example) bring the issue of stability on top of its relevancy. First, a construction of the roadbed, and then its exploitation in permafrost conditions lead to a degradation of the latter. It happens as a result of any technogenic system operation; the topography and hydrology in the adjacent territories being changed locally. However, a reverse process also takes place as the characters of cryogenic processes in the subgrade and the adjacent territory are considerably different. The consequences of these objective conditions are unrelenting danger of deformations and their continuity. It is supported by the fact that since the construction of the Amur–Yakutsk Mainline and the Baikal–Amur Mainline, their roadbed deformability has remained the same as far as the deformation average length on sections, namely from 25 to 32%.

2 Problems of Construction and Maintenance of Subgrade on Permafrost The origin of the problems connected with the cryogenic processes that cause the roadbed deformations lies in the thermodynamic imbalance in the “roadbedpermafrost” man-made/nature system [3]. Ultimately, the main factor determining the thermodynamic imbalance is the subgrade soil overwatering. The soil overwatering influences its bearing capacity. Thus, it requires a positive and civilized intervention into its strengthening and, consequently, stabilization of the roadbed in rough conditions of permafrost. Such an approach includes an expert and planned action that does not break into the self-restoration process of the nature-technogenic system “railroad roadbed-permafrost”. The complex approach of coordinated solutions for the problems that provide the roadbed stability is necessary. The analysis of patents, scientific, and technical literature shows that the issues of roadbed strengthening on weak soils including the permafrost territories are in

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the focus of all distinguishing engineering production and research institutions. It is confirmed by an increased number of sources concerning the research of technogenicnatural systems in railroad infrastructures on permafrost [4–6]. An overwhelming number of the sources concerns the problems of weak soils while the permafrost tasks are only a small part of the researches carried out by the leading foreign countries. The goal of all kinds of anti-deformation measures is to achieve high strength soil properties of the roadbed and the subgrade within the shortest time period and provide the longest period of the structure exploitation at the same time. After the Qinghai-Tibet Railroad was put into operation, and its location in the area of high-temperature permafrost has inspired a great interest of China to the problems of roadbed and structure base strengthening. It is confirmed by a considerable amount of patents on useful innovations that the Chinese researchers have received, and the papers they have published. The most prominent institutions worth mentioning in this connection are the Cold and Arid Regions Environmental and Engineering Research Institute, the Chinese Academy of Sciences, Lanzhou; the Central South University, Changsha. Most of the efforts are aimed at remediation of the consequences resulted from the processes in the “roadbed-subgrade” system. Unfortunately, the features of working projects on high-temperature permafrost soils characterized by continuous swamp areas and thermal karst are always individual. Besides, the Roadbed and Artificial Structures Maintenance Standards are out-dated and do not mainly reflect the real conditions in the southern part of permafrost area, thus requiring an amendment. In our experience, the cryogenic deformations are of the polygamous character; they are controversial and cannot always be treated in the recommended way or patented measures available. The long-term lab experience shows that practically all projects require a specific and individual approach. Besides, traditionally the cryogenic processes influencing the roadbed deformations are distinguished according to their character and time. During the examination of the embankment sections under deformations on the Amur–Yakutsk Mainline the engineers of FESTU observed some cryogenic processes of great scientific interest that are mentioned below. They cause the engineering problems that are solved with new technological design approach, and most of them are patented. First comes the permafrost degradation, a long-term thawing of the roadbed subgrade and cut slopes due to a malfunction of a natural heat exchange with the environment as a result of man-made impact of different origins, or soil settlement because of permafrost thawing in the roadbed subgrade. Then goes aufeis in the subgrade and the roadway that cause distortions in the track profile and its grade accompanied by a spring settlement of heaved soils and their sliding along the thawing front. The other cryogenic processes are thermal karstification, alluvial doline, aufeis formation, thermal erosion, thermal suffusion, spring water outcrop from the ditch slopes and filtering from the embankment. Thermal karsting is thawing of ice veins

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and layers in a strongly ice-rich permafrost of subgrade soils that is accompanied by water accumulation at the roadway and drainage structures with the following settlement and alluvial dolines in sedimentary. Solifluction is a slide of thawed soils from the embankment and ditch cut slopes that cause instability of slopes and the structures themselves. Aufeis formations in ditch cuts, zero levels and embankments are ice mass formations on the surface when the flow cross-sections of underground and surface waters accumulated on their way to or into the openings of artificial structures get frozen. Thermal erosion of the subgrade embankment and the drainage structures are resulted from a water flow impact leading to instability of the slopes. Thermal suffusion is a soil washout from the subgrade and ditch cuts resulting in considerable settlement and track displacement. Drainage-filtering phenomena are spring water outcrop from the ditch slopes and drainage structures as well as filtering from the embankment [7]. The following examples show how specifically the engineers of the Substructures and Foundation Lab, FESTU, approach hazardously deforming projects. The projects are examined first for the problems that are to be eliminated as a complex by different methods. Then, some strengthening designs are developed. The given examples prove that the cryogenic processes influencing deformations in the embankment are, on the one hand, of independent nature but, on the other hand, they considerably affect each other.

3 Examples of Effectively Realized Complex Solutions for Providing Roadbed Stability on Permafrost The paper gives an example of effectively realized solutions by the engineers of the Substructures and Foundation Lab on the Berkakit-Tommot section, the Amur– Yakutsk Mainline, KM 116 Block Oganior-Tayozhny (in 2006) and KM25 Block Denisovsky-Chulman (in 2009). However, the sections where the measures are not taken (KM28 of the Denisovsky-Chulman section and KM58-59 of the TenistyChulbas section) show a progressing deformability. It is confirmed by the geometry car tapes of May, 2015 and 2018. KM116 Block. The embankment is a cut-and-fill in karst dolomite rocks. The alluvial dolines occur there because of ice thawing as a result of thermal karstification processes. In 2004, a sinkhole occurred under the track, and the train car wheel dipped. These hazardous deformations are accompanied by such cryogenic processes as frost fracturing in rocks and their subsequent destruction that produce a negative effect on heat exchange of soils and the air; underground waters squeezed from the tectonic fractures contribute to dissolving of the dolomite rocks, filling the cavities with water that turns to ice, thus leading to sinkholes in the roadbed and slopes.

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Fig. 1 Embankment stability on thermal karstification section, KM116 Block

A complex of stabilization measures includes diverting of ground water with a help of the insulated drainage, removing of the current track to a reinforced subgrade, optimizing the temperature regime in cut soils with filling the cavities and levelling the slope surface as well as cutting a system of ditches. The measures were fulfilled in 2006. The geometry car tapes that prove the roadbed deformability has not worsened for the following years (see Fig. 1). Deformations on KM25 Block Denisovsky-Chulman are the consequences of 5 m thick ice massive thawing that leads to cavity formations, thus accounting for soil instability. It is the result of water encroachment, the following mechanical suffusion and washing out of fine fractures under the hydrodynamic pressure from the embankment subgrade during a pre-winter period. The settlements are resulted from a plastic extrusion of weak soils (the embankment shifted to the right) because of the soil destruction and rock fragmentation due to a pressure filtration of ground waters and their seasonal freeze-thaw process. Appearance of ground waters from the underground and surface waters from a high side of the terrain leads to water encroachment. The deformations on the section had been permanent since its construction up to 2009, and the traffic speed limits had been kept up to 40 km/h. A complex of anti-deformation measures is developed to eliminate the current deformations and provide the further stability of the deformed roadbed section. The developed complex is considered an invention and registered with a patent as a structure of the “counter dam of a variable cross-section” in a complex with a drainage system. The structure allows to decrease the railroad track maintenance cost, avoid the speed limit on the section and improve the appraisal by points factor of track conditions. The geometry car tapes that prove the roadbed deformability has not worsened for the following years (see Fig. 2).

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KM25, May 2015

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Fig. 2 Geometry car tapes showing effectiveness of anti-deformation measures, 25 km Block

An examination of another deforming section (KM58-59) shows several causes of degradation, namely the ice suffusion along almost the whole section. The most hazardous part on a curve is strengthened with the counter dam while the high side section is reinforced with a specially developed and patented two-step drainage structure for ground and surface waters. An elastic ramp (previously patented) is used on a section with sinkholes (KM59), and a trenchless isolating drainage system (also patented) is used on a section with aufeis. The roadbed deformations on the section are of a progressing character that is proved by the geometry car tapes of 2015 and 2018 (see Fig. 3). The yard neck of Chulman Station (KM28) has been experiencing permanent deformations since its introduction. First, there is a settlement of 250 mm per year on a section with thaw underground ice. Next, after its thawing out, the ice heave phenomena and mechanical suffusion appear. There are also sinkholes due to soil washing out from a hollow in the roadway where a small artificial structure is not planned to be designed during the construction. The phenomena contribute to a malfunction of side ditches and appearance of considerable deformations of heave-settlement character on the permanent way. This requires an introduction of speed limit on the main and station tracks every winter season. FESTU have developed the measurement for these phenomena elimination, though not all of them have been fully put into practice. The geometry car tapes proving the above mentioned (see Fig. 4).

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Fig. 4 Geometry car tapes on KM58-59 Block showing high deformability of roadbed and speed limits (necessity of the measure offered is evident)

4 Conclusion 1. The paper focuses on urgent problems of maintenance and stabilization of the roadbed in the conditions of cryogenic deformations in severe climatic conditions of the Russian Far East. Considerable changes due to external and internal processes take place in the man-made/natural system “roadbed-permafrost” during its long-term exploitation. 2. Natural restoration processes in the man-made/natural system “roadbedpermafrost” go on very slowly for more than 15–18 years when the exploitation conditions remain unchanged.

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3. Many years of experience for regime observations on the Baikal-Amur Mainline and the Amur-Yakutsk Mainline allow the Substructures and Foundation Lab, FESTU, develop and introduce anti-deformation technical solutions successfully. They turn out effective in case of an individual complex approach that does not break into the natural processes but only contribute to a faster self-restoration of the “roadbed-permafrost” man-made/natural system.

References 1. Zhdanova S, Dydyshko P (2005) Strengthening of an earthen cloth on the basis in the conditions of increase axial and loadings. Publishing House DVGUPS, Khabarovsk 2. Zhdanova S (2005) Nonconventional aspects of influence vibratsionno-dynamic loadings on stability of the bases and slopes of an earthen cloth. Publishing House DVGUPS, Khabarovsk 3. Zhdanova S, Katen-Jartsev, Shulatov A, Odnopozov L (2003) About results of researches of influence vibratsionno-dynamic loadings on weak soils the bases and a new technique of diagnostics of their condition in the course of monitoring. The bulletin of electromechanics of a railway transportation. V.1. Energo resource savings on a railway transportation, pp 365–368 4. Mecke A, Lee I, Baker JR Jr, Banaszak Holl M, Orr BG (2004) Deformability of poly (amidoamine) dendrimers. Eur Phys J E 14:7 5. Ben Rabha M, Boujmil MF, Saadoun M, Bessais B (2009) The use of chemical vapor etching in multicrystalline silicon solar cells. Eur Phys J Appl Phys 47(1) 6. De Lillo F, Cecconi F, Lacorata G, Vulpiani A (2008) Sedimentation speed of inertial particles in laminar and turbulent flows. EPL 84 7. Belenkov E, Zhdanova S (2011) Puchinno-nalednye the phenomena, as the most dangerous kinds of cryogenic deformations. In: The international geotechnical symposium «Preventive measures on reduction of natural and technogenic disasters», DVGUPS, pp 279–284

Intelligent Onboard Train Protection System for the Northern Territories Efim N. Rozenberg and Vladimir Batraev

Abstract In the context of the 2030 Russian Transport Strategy, the development and implementation of advanced technologies in extreme conditions (such as the Northern Latitudinal Railway), the enterprises and research institutes of JSC RZD are faced with the task of developing next-generation integrated systems. Thus the BLOK-M system (JSC NIIAS, Oktyabr Manufacturing Group) was developed. BLOK-M is a scalable integrated train protection system that enables intelligent integration with train control systems. Functionally flexible high-performance hardware allows for system configured upon customer request. Today, JSC NIIAS in close cooperation with JSC VNIIZHT equips dozens of rolling stock units with the BLOK-M-based ATO-capable integrated train control and protection system. BLOK-M, along with the conventional train protection functions, features advanced solutions that enable further railway infrastructure development and implement integrated systems architecture. In close cooperation with the leading enterprises of the Russian Academy of Sciences and ROSATOM, the onboard equipment was redesigned with the use of domestically-manufactured components, thus solving the problem of information security and improving the dependability of equipment. Keywords Onboard computer-based systems · Cyber threats · Integrated train protection systems

1 Introduction Today, the requirements of the complex project of the Northern Latitudinal Railway (NLR) as the transport corridor to the gas and oil-producing regions of West Siberia pose new challenges to JSC RZD and the national authorities that need to be solved, while recognizing the responsibility and importance of the project. The line will primarily transport oil, gas and petrochemical products. According to the company’s estimations, the flow of goods will exceed 20 million tons per year. In this regard, it is E. N. Rozenberg (B) · V. Batraev JSC NIIAS, Bldg. 1, 27 Nizhegorodskaya Str., 109029 Moscow, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_25

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worth noting that the NLR crosses protected environmental territories of the YamalNenets Autonomous Okrug with adverse climate conditions. Thus, traffic safety and operation of train control systems are of great importance. The safety of railway transportation as a complex technological and process design system requires a coherent engineering policy that enables the operation, improvement of existing traffic train protection systems (onboard and station-based), development of railway infrastructure, as well as new regulatory technical documents and their updating taking into account the mitigation of the human factor [1, 2]. In this context, we should highlight the new class of equipment that not only can be operated in low temperature conditions but also has a high level of survivability and dependability compared to the counterparts designed for moderate climate, as well as advanced diagnostics to reduce maintenance time and staff, capability to ensure traffic safety to prevent human-made disasters, whose consequences may be irreparable for the fragile ecosystem. One of the primary tasks of railway system development consists in increasing the dependability and safety of technical facilities under conditions of high rate of traffic and, thus, considerable static and dynamic impact on the infrastructure. The solution relies on the assessment of the dependability and safety indicators of infrastructure facilities and prediction of their changes. The above tasks require a comprehensive approach to the improvement of train control and protection systems, elaboration of the principles for their functional development along with the infrastructure development, analyzed to identify the failure rate according to the URRAN method based on the KAS ANT statistical indicators of the number of failures. The enterprises and research institutes of JSC RZD were tasked with developing innovative technical systems and integrating the existing advanced solutions for the NLR and Northern territories. JSC NIIAS were tasked to develop a new-generation onboard unit—the Integrated train protection system.

2 Problem Description The innovative onboard system is to: • be a scalable integrated train protection system with intelligent interfaces to rolling stock control systems, • be configurable on the customer’s demand thought functionally flexible highperformance hardware and software, • have various radio-based interfaces for reliable information transmission between trackside equipment, including newly developed systems, • have a cybersecurity component and use domestically-manufactured components, • have higher dependability and better functionality compared with existing onboard systems through advanced data processing algorithms.

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The BLOK-M integrated system by JSC NIIAS, NPO SAUT and Oktyabr Manufacturing Group have become such single control and train protection system (Fig. 1). The issues of equipment reliability and its noise resistance will be very urgent if BLOK-M is operated in the northern territories. The fact is that in practice, noise resistance indicators are significantly lower than the theoretical estimates of error probability, which are given in [3, 4], when receiving elementary symbol under the conditions of Gaussian noise. Pe = V (α) 1 where V (α) = √2π

(1)

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α 2 = E/2 · N0 is for signals with passive pause (Amplitude Modulation), α 2 = E · (1 − ρ)/N0 is for signals with active pause (Frequency Modulation, ρ = 0; Phase Modulation, ρ = −1), E is the energy of the elementary signal with the duration of τ0 , N0 is the spectral-noise power density. Passing of a series of information symbols through individual elements of any communication system is always accompanied by transition processes due to the limited bandwidth of these elements that leads not only to misrepresentation of individual messages but also overlapping of residual voltage from the previous messages. Another limiting factor for the high quality of information reception is the difficulties with both element and code combination synchronization between the transmitting and receiving sides. These difficulties increase due to intersymbol interferences that cannot be eliminated by increasing the signal level.

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3 Methods and Algorithms In BLOK-M, element, high-frequency and group synchronization were implemented to increase noise resistance of signal processing. Since the sync pulses are generated through the input sequence of the information symbols, the registration error generally depends not only on the frequency distribution of the synchronization error ω{λ = ε/τ0 } that occurs due to noise in the path, but also on statistics of the receiving symbols. The scrambling effect and the effect of the adopted symbol sequence on the error condition was taken into account by approximation [5] Pp (λ) = [1 − 2 · p(1 − p)] · P1 (λ) + 2 · p · (1 − p) · P0 (λ)

(2)

where p is the probability of the single symbol transmission, P1 (λ) is the error probability (1) with symbols of one polarity, P0 (λ) is the error probability (1) with reverse polarity. Figure 2 shows the results of numerical calculation of the magnitude estimation of the average error probability of reception against signal–noise ratio and synchronization ideality under averaged (2) as in [6] Pp∗

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−1 √    where ω(λ) = 2 · π σλ · exp −0.5 · (λ σλ )2 is the frequency distribution of synchronization error. Out of the comparison of the calculated curves follows that the upper limit of the real value of the synchronization standardized error is the value up to 0.05–0.06, while the loss of energy does not exceed 0.5–2.0 dB for the error probability of Pp ≤ 10−5 . Further, starting with σλ ≥ 0.07 − 0.1, the loss of energy exceeds 3 dB and increases sharply, and noise resistance degradation is 2–3 even with signal–noise ratio of more than >12 dB. As a result, data transmission channel performance in this context is lower than estimated, and the communication zone, including radio communication with rolling stock units, will be significantly reduced. It should be noted that in practice noise resistance during data transmission also depends on the applied architectural solutions and specific aspects of the development. For the traffic safety-related equipment the assessment of error probability of data reception should be not lower than 10−4 –10−5 .

4 Evaluation of Results These technical solutions were successfully tested at Sverdlovsk Railway by JSC “Sverdlovskiy PRMZ “Remputmash” and at North Caucasus Railway by JSC TMZ named after V.V. Vorovskii. In particular, within the framework of signalling system, this complex is installed on AS-01 and MPT-6 rolling stock as well as tested on AM140 railcar. This system is also installed on 2ES6 and ES1M electric locomotives [7–10].

5 Conclusion In BLOK-M, through the new processing algorithms, the dependability of discrete information reception has been increased and specific recommendations both on signal generation via station equipment and on receiving signals onboard have been developed. The performed analytical studies and practical experiments allow minimizing reception errors caused not only by external factors but also by errors in the measurements of information parameters for these signals with angle modulation. JSC NIIAS, in close cooperation with JSC VNIIZHT, is equipping dozens of rolling stock units with an ATO-capable integrated control and train protection system with redundant control system data display. BLOK-M, along with the conventional train protection functions, features advanced solutions that enable further railway infrastructure development and implement integrated systems architecture.

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In combination with the remote sensing subsystem with detection of vibroacoustic impact of train movement on the optical sensor installed along the track, intellectual on-board unit BLOK-M will ensure reliability of train operations within the framework of NLR project.

References 1. Igarashi T, Aoyagi M, Ubukata R, Amiya N, Tobita Y (2010) Automatic train control system for the Shinkansen utilizing digital train radio. WIT Trans State Art Sci Eng 46:27–35 2. Ning B, Tang T, Qiu K, Cao C, Wang Q (2010) CTCS—Chinese train control system. WIT Trans State Art Sci Eng 46:1–8 3. Tihonov VI (1996) Statistical radio engineering. Sovetskoye Radio, Moscow 4. Fomin AF, Vavanov YuB (1987) Noise resistance of railway radio systems. Transport, Moscow 5. Ginzburg VV, Kayackas AA (1974) Demodulators synchronization theory. Svyaz’, Moscow 6. Rozenberg EN, Batraev VP (2005) Influence of synchronization on noise stability of data receiving via narrowband. Trudy VNIIAS 2:121–128 7. Rozenberg EN, Batraev VV (2017) Development of advanced control systems and ensuring the safety of train traffic. Bull Joint Sci Counc JSC Russ Railw 4:43–50 8. Rozenberg EN, Korovin AS, Batraev VV (2013) Development of onboard and wayside safety control systems that minimize impact of the human factor. Bull Joint Sci Counc JSC Russ Railw 5:24–35 9. Rozenberg EN, Dziuba YuV, Batraev VV (2018) On directions of digital railway development. Avtomatika, svyaz’, informatika 1:9–13 10. Gapanovich VA, Rozenberg EN, Shubinsky IB (2014) URRAN system for the Olympic Sochi innovative traffic management systems based on novel risk management methodology. RailwayPro 2.6 108:40–43

Transport Construction of the Mainland—Sakhalin Island Ekaterina Shestakova, Anatolii Novikov, Anatoly Antonyuk and Pavel Kurchanov

Abstract The article discusses issues with a high degree of preparation for the design, construction and operation of artificial structures of transport infrastructure, in the difficult climatic conditions of the Sakhalin region with a long winter season with abundant winter precipitation, hazardous deposits of ice and ice freezing, and taking into account high-seismic activity territory. The authors presented the results of work on assessing options for the development of transport infrastructure by providing a message to the mainland of the Russian Federation and Sakhalin Island through the Nevelsky Strait, with the rationale for a solution to the problem of a transport transition and an assessment of the tunnel-bridge alternative. The effectiveness of the solution is predetermined in the use of two main options: a tunnel (or a tunnel-dam) and a combined version of a tunnel-bridge; two static schemes taking into account the uniqueness, III category of complexity, heterogeneity of the structural-tectonic conditions of the transport transition for the mainland and island parts. When designing transport facilities for Sakhalin, specific features should be taken into account, namely, difficult climatic conditions, the peculiarity of the economic and geographical position (Russia’s only region on the islands, proximity of Japan and other rapidly developing Asia-Pacific region), the current structure of the economy, the uniqueness of the resource potential (biological and hydrocarbon resources of the shelf are of regional and national importance), economic and social development, integrated development and development the non-raw material base of the Far East, industrial development of the regions, major logistic schemes and the prospect of total cargo turnover (The Eurasian Land Bridge) and the potential for the development of the tourism industry. This could change the economic picture of Sakhalin and contribute a big share in the economy of Russian. The rich natural, cultural and historical potential of Sakhalin Island has not yet been fully utilized in the development of international and intraregional tourism. The use of innovative technologies to solve engineering problems will be focused on the requirements for

E. Shestakova (B) · A. Novikov · A. Antonyuk · P. Kurchanov Department “Bridges” and “Tunnels and Subways”, Emperor Alexander I St. Petersburg State Transport University (PGUPS), 9 Moskovsky Pr., St. Petersburg 190031, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_26

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modern artificial structures: reliability and durability, safety and efficiency throughout the life cycle. The choice of the best option, taking into account the alternatives “tunnel-bridge” will be carried out on the technical and economic indicators of total, construction and operating costs, including the payback period, the cost of emergency situations, seismic and environmental safety. Keywords Bridge · Tunnel · Transport connection · Mainland · Sakhalin Island · Finance

1 Introduction To determine the possible sources of financing for the creation of a transport passage through the Nevelsky Strait, it is advisable to analyze the existing international experience. Currently, in the world, there are a number of constructed and projected transport crossings aimed at the development of transport corridors and the formation of a single transport space and global market. The Öresundsky tunnel bridge between Denmark and Sweden [1] and one of the world’s most famous underwater tunnels under the English Channel between France and the UK can be attributed to the built transport crossings between states. These structures, after many decades, continue to inspire engineers and builders to create super-scale structures and superstructures, the implementation of which can begin in the near future at mega-constructions of our planet [2–4]. In recent decades, major investment projects have been considered for creating transport links between various territories, such as the construction of a tunnel under the Strait of Gibraltar between Port-Tugalia and Morocco, a tunnel under the Gulf of Finland between Estonia and Finland, a tunnel under the Bering Strait between the Russian Federation and USA and others. According to experts, each of these projects can give a huge economic effect, but, at the same time, the cost of building such projects is also very significant. The construction of ambitious super-projects is distinguished by extremely complex engineering meteorological and geological conditions, depths of foundation foundations of supports up to 100 m, and increased requirements for maritime navigation with the involvement of specialists in related specialities (navigation of sea waterways, shipbuilding, marine hydrology and meteorology). Engineering projects of future unique transport crossings of considerable length across the straits are discussed in detail in the thesis by Martire (2010) The Development of Submerged Floating Tunnels as an innovative solution for waterway crossings [5], as well as at symposia and conferences [6–8]. In determining the sources of financing, it is necessary to evaluate the possible benefits of creating a transport transition and search for investors interested in improving the transport infrastructure of the region. In particular, Sakhalin Island is one of the richest regions of the mineral resource sector of the country’s economy. Sakhalin Island produces the most important energy resources, namely oil, gas

Transport Construction of the Mainland—Sakhalin Island Table 1 Projects with private investment in developing countries for the period 1990–2018

Infrastructure

Number of projects

251 Cumulative investment (million dollars)

Railways

140

120,951

Highways

1024

298,730

Sea ports

457

86,870

and coal, but the island’s transport infrastructure is not sufficiently developed. In accordance with the data presented on the official Web site of the governor and the government of the Sakhalin region, transport infrastructure has one of the lowest rates of hard-surface roads (41.6% of the total length of roads, 65.2% of the length of roads DFO), lagging behind this indicator from the average Russian value (85.2%). In addition, significant investments are required in the railway infrastructure. There are two main options for the modernization strategy of the transport infrastructure of the Sakhalin region: improvement of the existing transport communication scheme, which involves changing the railway from 1067 mm to modern 1520 mm and the development of the transport complex—connecting Sakhalin by a bridge (tunnel) to the mainland through the Nevelsky Strait. Thus, the most logical step in implementing the construction of a transport passage to Sakhalin Island is the use of both public funding and the attraction of private funds from companies interested in developing the transport infrastructure of Sakhalin for their projects, i.e., public–private partnership (PPP). This financing option is widely used in the world when implementing large projects. In recent years, developing countries have accelerated the pace of reforms aimed at improving conditions for starting and running a business, the World Bank Group’s annual survey, measuring indicators of favorable business conditions, notes. The data given in Table 1 shows that the public–private partnerships have become a real replacement and alternative to the program of full privatization of transport infrastructure facilities [9]. The most common form of interaction between the state and business in the field of road management is a concession. It should be noted that the first road projects in Denmark and Sweden, the Great Belt, and the bridge across the Oresun Strait were approved by society, as they were an economical alternative to ferries. Public–private transport partnership in Russia is traditionally the most actively developed in the field of road construction and maintenance. The first projects of PPP in Russia were the construction of the Western High-Speed Diameter (WHSD) in St. Petersburg and the section of the Moscow–St. Petersburg expressway (SPAD), the construction of a bypass of the city of Ufa, etc. PPP projects in the road sector of the Russian Federation are carried out relatively recently, in fact the situation changed in 1992 with the enactment of the presidential decree of December 8, 1992 N 1557 “On the construction and operation of highways on a commercial basis”, but despite all the difficulties in the context of the crisis of the global financial system, the authors express the hope that the future project will be a landmark for the transport infrastructure for the next decades in the context

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of the formation of transcontinental corridors, with the involvement of Japanese, Chinese, Korean and other foreign capitals for long-term and capital-intensive megainfrastructure projects, interested parties from participating countries.

2 The Main Difficulties Affecting the Choice of Transport Transition The main features of the design of transport transition through the Nevelsky Strait: (1) High-seismic activity of the construction area. (2) The geological conditions of the possible part of the transport junction for the mainland and island parts are very different. On the mainland, igneous rocks prevail, on the island—sedimentary rocks stretching tens of meters in the strait. The different geological structure of the mainland and island parts of the strait implies the presence of a tectonic fault (even a few are not excluded). This carries a high probability of shear phenomena along faults, which should be taken into account when developing transport transition projects. (3) The location of the bridge over wind pressure, at least in the V region—according to SP 131.13330.2012 “Building climatology. Updated version of SNiP 23-0199 * (with amendments No. 1, 2). (4) Natural and climatic factors, especially during the winter period, are very severe: storm winds, snowstorms, intense snowfalls, icing of structures, ice phenomena. The settlements closest to the bridge transition have the following indicators: the absolute minimum temperature is minus 47 °C, the average monthly temperature of the coldest days with a security of 0.98 is minus 34–41 °C; the absolute maximum temperature is plus 31–35 °C. (5) Water depths in the strait at the transition point are 21–23 m. (6) The hydrological situation is characterized by a change in the direction of the flow in the strait, its high speed, ebbs and flows, significant alluvial sediments and their erosion. (7) The presences of a continuous ice cover in the strait in the cold season. Abnormal frosts, strong winds (on February 11, 2019 a storm warning was recorded, minus 43.7°, winds of up to 35 m/s, cyclone passing over the Tatar Strait, heavy snowfalls, mountainous areas, the danger of avalanches, icing of structures)— these are the peculiarities of the northern climate that designers, builders and maintenance services will encounter according to the Ministry of Emergency Situations of the Russian Federation in the Sakhalin Region. These adverse, harsh and cold weather conditions complicate the implementation of many types of construction and installation works, increase the danger at construction sites, limit or completely eliminate cranes, endanger the destruction of structures, impede the movement of repair and repair teams, increase power consumption. A unique project must be implemented with the participation of private investors who are interested in supporting

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and investing in the application of innovative technologies and the development of energy efficiency programs and renewable energy. Energy efficiency measures will pay off in a cold and remote area of Sakhalin much faster than in the European part of the Russian Federation, up to 4–5 times, according to the Center for Energy Efficiency.

3 Possible Variants of Structural and Technological Solutions for the Transport Transition When developing transport transition projects between Sakhalin Island and the mainland of the Russian Federation. Three main options for structural and technological solutions are considered: a bridge junction, a tunnel constructed by the immersed tube, and a tunnel constructed by the shield method. Each of the options presented has its advantages and disadvantages. Option 1: Bridge crossing The practice of world bridge building already has successful examples of the design and construction of road and combined bridge crossings under the most difficult conditions of high seismicity and complex tectonics, in the presence of a powerful stratum of weak soils at the base and high-intensity wind effects. Such examples include the combined Oresundsky tunnel bridge, the bridge to Russky Island (Russia), the combined bridge crossing between the Taman peninsula and the Crimean peninsula, the bridge crossing through the Bosphorus (Turkey), etc., create a bridge across the Nevelsky Strait. At the same time, the factors listed in Sect. 2, such as high wind loads, low temperatures, difficult sea conditions and high ice loads, significantly complicate the work and increase the cost of construction, and subsequently the maintenance of the bridge. In 2013, the Giprostroymost Institute made preliminary design sketches for a single-track railway bridge. The proposals are focused on the construction of lattice trusses. In the first version, a scheme was adopted using two continuous spans (2 × 330 m); nine continuous spans (2 × 220 m); two farms 220 m long; one single-span structure with a length of 110 m and two-beam span structures of 33.6 m each. The total length of the bridge is 5948.04 m. The number of intermediate supports is 26. In the second version: two continuous span structures (2 × 330 m); six continuous spans (2 × 220 m); 17 single-span trusses 110 m long and two-beam span structures of 33.6 m each. The total length of the bridge is 5960.04 m. The number of intermediate supports is 34. Both options in this version do not solve all the problems of reliable communication for many years between the mother and the island. There should be taken the design of transport communications, providing a two-way pass of railway rolling stock, as well as the necessary traffic flows. Constructive solutions of the span options

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are not suitable for the device of the second tier during the movement of transport, and the internal dimensions cannot provide a double-track rail link. A large number of intermediate supports (from 26 to 34) will cause complex erosion processes in the channel, and how they will affect the alluvial sediments in the channel in the future is unpredictable. Both options do not meet the external climatic factors. First, inevitably a strong icefreezing on numerous elements of lattice spans in the winter. Secondly, the significant seismic activity of the region in case of possible earthquakes and the shift of tectonic plates of the continental and island parts can affect the lifetime of the artificial structure. The solution of the indicated problems can be achieved at the expense of other design schemes, including those already known in world practice. Seismic effects and possible tectonic displacements in the zone of transport transition as a threat may be eliminated by hanging or hybrid cable-cable systems. In world practice, bridge building designed, built and built dozens of large-span bridges with central spans from 1000 to 2000 m and more. A number of them provide a pass combined (road and rail) traffic. At present, a third hybrid cable-cable-stayed bridge with a central span of 1,408 meters has been built across the Bosphorus, which provides for a double-track rail link and four lanes in each direction. In this article, the authors propose to consider the design scheme and 3D visualization of the hanging combined bridge over the Nevelsky Strait with a central span of 700 m (see Figs. 1 and 2). In order to optimize the operation of the intermediate pylon construction, the stress-strain state was evaluated in the SOFiSTiK software package by comparing the basic static schemes. The finite element model of the stiffness beam and the pylon is represented by rod beam elements, carrying cable and suspensions—elements that work only in tension. The stiffening beam has pivotally movable points of support at the ends and at the bridge of the pylon along the axis of the bridge. At the base of the pylon is rigidly fixed. The peculiarity of multi-span suspension bridges can be attributed to reduced vertical stiffness in the case of asymmetrical loading of one of the spans, and with an increase in the number of spans, the overall rigidity of the system continues to

Fig. 1 Design scheme of the suspension bridge

Transport Construction of the Mainland—Sakhalin Island Fig. 2 Stress-strain state of the main pylon options: rigid (1 and 2) and flexible (3) pylons

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(1)

(2)

(3)

decrease. The use of multi-span suspension bridges without the adoption of special measures to increase their rigidity is almost impossible. As such a measure can be applied device hard pylons. Let us consider several constructive solutions of pylons and the influence of the form of the pylon on the overall operation of the structure. As a calculation, a two-tier suspension bridge was used, shown in Fig. 2. A stiffening beam box-shaped cross section with an orthotropic roadway plate. Beam material is steel with modulus of elasticity E = 200,000 MPa and bulk density ρ = 78.5 kN/m. The main carrier cable d = 0.7 m from steel E = 200,000 MPa and volume weight ρ = 78.5 kN/m3 . Suspensions d = 0.15 m from steel E = 200,000 MPa and volume weight ρ = 78.5 kN/m3 . Frame pylon according to scheme 1: at the base, an envelope of 6 × 6 m, wall thickness 0.7 m, at the top 4.5 × 4.5 m, thickness −0.5 m.

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The material of the pylon is reinforced concrete with elastic modulus E = 27,500 MPa and volume weight ρ = 25.0 kN/m3 . Frame pylon according to scheme 2: at the base (inclined racks), the envelope is 4.5 × 4.5 m, the wall thickness is 0.5 m, at the top 5 × 5 m, the thickness is 0.5 m. The material of the pylon is reinforced concrete with elastic modulus E = 27,500 MPa and volume weight ρ = 25.0 kN/m3 . Flexible pylon according to scheme 3: section dimensions 5 × 5 m, wall thickness 0.5 m. The material of the pylon is reinforced concrete with elastic modulus E = 27,500 MPa and volume weight ρ = 25.0 kN/m3 . A rigid A-shaped pylon fully meets the requirements of rigidity and strength, but due to its low compliance, the pylon transfers considerable effort to the foundation, which, as a result, greatly complicates the design of the support foundation. In addition, the construction of the pylon with such a complex geometric shape is associated with great difficulties. Increasing the flexibility of the pylon in the direction along the bridge could unload it. Thus, we proceed to the consideration of a Y-shaped pylon (scheme 2), which has sufficient flexibility, but at the same time retains the ability to perceive horizontal forces from the main carrier cable. From the results of the calculations, it becomes clear that the traditional form of the pylon (scheme 3) cannot be applied in a multi-span suspension bridge without the application of additional measures to increase the vertical stiffness. At the same time, the construction of such a pylon is the simplest, unlike other schemes. Pylon option No. 1 was recommended for further development based on estimates of bending moment and displacement diagrams. Option 2: The tunnel constructed by the method of immersed tube The first tunnel crossing from the immersed tube in Europe was constructed from 1937 to 1942 near Rotterdam (The Netherlands). At present, this technology is widely spread in the global tunneling industry. A large number of transport junctions built and operated in the world, including tunnels from the immersed tube, testifies to the effectiveness of this method of construction [8]. Examples of implemented construction of transport crossings using immersed tube include the construction of the Eresunsky tunnel bridge with a length of 4,050 m, the construction of the Busan-Kodge road transport tunnel (South Korea) with a length of 3,200 m, and the sub-section of the Marmaray tunnel under the Bosphorus (Turkey) 1400 m long and a tunnel section of a transport junction between Hong Kong and Macau (China) with a length of 4200 m. However, in Russia there is only a small experience of building tunnels in this way. So from 1975 to 1983 of the last century, a tunnel in St. Petersburg on Kanonersky Island was built by means of immersed tube. It consists of six sections 110 m long each, section 13.2 × 7.9 m. [7]. The construction of the lower section has several advantages, such as: 1. The simultaneous production of a large number of sections of the tunnel on the coast and the combination of the construction time (construction of sections, preparation of trenches and transportation of sections) allows to significantly

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accelerate the pace of work, using technological advances characteristic of modern production of concrete products. 2. The cross section of the tunnel from the immersed tube should not necessarily be cylindrical (as required when the shield penetration), it is possible to construct tunnels with different cross-section shapes. 3. Tunnels from immersed tubes can be built for any type of soil, including soft alluvial, since the pressure of the sections on the ground due to the large bearing area is slightly different from the pressure of the soil replaced by the tunnel in natural conditions. 4. The tunnel junction of the immersed tubes, as a rule, is shorter than the junction constructed with the help of the TFMK. At the same time, when constructing a tunnel in this way, a number of issues will need to be resolved. 1. First, it is necessary to exclude the destructive influence of the object under construction on the hydrological phenomena in the strait (erosion of alluvial sediments, change in the velocities of oppositely directed currents), which is achieved by deepening the tunnels and subsequent backfilling of the soil. It is also possible to give sections of an external streamlined ellipsoid shape. 2. Secondly, the impact of shifts in the fault zone can lead to a violation of the waterproofing of the tunnel. The effect of shifts can be reduced by using special gaskets between sections, ensuring tightness, relative displacements and turns of the tunnel section ends without damage, or providing for the intersection of faults in a single-section design with preliminary compression by pre-stressed reinforcement (protected against corrosion). 3. In world practice, there is no experience in building tunnels from immersed tubes longer than 4,200 m, while creating a transport crossing under the Nevelsky Strait will require the construction of a tunnel from immersed tubes with a total length of at least 8,000 m. 4. It is quite difficult to transport sections in conditions of significant currents in the strait and difficult wave conditions. Option 3: The tunnel constructed by shield method The construction of long transport tunnels with the help of tunnel-driven mechanized systems is currently a fairly common task. As an example of such projects implemented, the Great Belt Tunnel (Denmark) and the Channel between France and Great Britain, which serves as a benchmark for structures of this kind, can be called. A typical solution for all currently designed transport crossings with the use of shield penetration is the construction of three tunnels: two single-track transport railways and a small diameter service tunnel between them. To simplify the ventilation system, as well as minimize the diameters of the tunnels, it is advisable to organize the transport of vehicles by rail on special platforms. A possible design solution of the tunnel is presented by the authors in Fig. 3. The tunnel construction option in the form of shield sinking has the following advantages.

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Fig. 3 Possible constructive solution of the tunnel on Sakhalin Island

1. Shield penetration technology has been repeatedly tested. Domestic tunneling organizations have considerable experience in the design and construction of tunnels, including in complex engineering and geological conditions [7]. 2. During the construction of tunnels using the shield method, using modern tunneldriven mechanized complexes based on shields with active bottom loading, the construction of the tunnel does not have a significant impact on the environment and practically does not depend on climatic conditions. 3. The tunnel lies at a greater depth than the tunnel from the immersed tubes and is less susceptible to seismic effects than the tunnel from the immersed tubes or bridge. It should be noted that seismic effects constitute a significant proportion of the loads in the calculation of tunnel linings, which should be taken into account in the design. In accordance with preliminary calculations, the most dangerous is the combination of the main loads (loads from rock pressure, hydrostatics and dead weight of the lining) and vertical seismic loads (see Fig. 4). 4. An important issue is the problem of ensuring the durability of the tunnel lining under the influence of seawater, as well as ensuring the integrity of the lining. According to the results of the calculations, the highest values of bending moments are achieved when the direction of loads from the weight of water and soils above the tunnel, its own lining weight and vertical seismic loads coincide. With a lining thickness of 450 mm and a class of concrete B60, the maximum values of bending moments were 143.9 m, which is not the limit for existing lining. As one of the options for increasing the resilience to the corrosive effects of seawater, it is possible to use special grades of concrete with additives that increase the homogeneity of the concrete mix and, as a consequence, increase the water resistance and corrosion resistance. Improving the waterproofness of the lining and block joints can be achieved by a device of continuous waterproofing on the internal

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Fig. 4 Plots of bending moments and displacements in the lining of the tunnel in the sub-sectional area with different loading options

surface of the team lining and the device of the inner lining of monolithic reinforced concrete [10]. 5. Among the disadvantages of tunneling options in comparison with the pavement often include their increased construction cost. However, the constructions carried out abroad in recent years and the design projects developed by COWI & Partners LLC, Consulting Engineers and Planners show that in modern conditions when using progressive structures and work methods, the difference in the cost of extended unique structures usually does not exceed 15% (e.g., for the Øresund Bridge and the tunnel −13.8%). At the same time, during further operation, especially in harsh climate, the operation of the tunnel variant turns out to be more economical according to the data of Lenmetrogiprotrans JSC in the conditions of the Russian Far East (the analog

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is a railway tunnel under Amur with a length of 7198 m in Khabarovsk, built in 1937–1941 years to duplicate the bridge over the Amur) [10]. Consider the analog method as the most effective tool for obtaining an objective and operational assessment of the future transport project. Previously, taking an analog of the Eresundsky bridge (a two-tiered bridge 7845 m long, 2 × 15.5 + 15 m wide), the cost of the Sakhalin bridge 6000 m long will be—C = 0.465 × 6000 × 66/1000 × 1.15 = 211.5912 billion rubles in the price level of 2017, taking 0.465— the cost of the analog per 1 m of the bridge structure, $ million in the price level of 2017; US dollar rate in 2017—66 rubles; with the subsequent use of an index of the recalculation of the estimated cost of construction and installation works (SMR) for the Sakhalin Region equal to 1.15, see p. ISSO—adj. 1. Industry enlarged estimated standards ONTsCRZ 81-02-07-2017 “Railways.” According to the data of the bridge, the annual maintenance costs will be approximately 0.5% for the first 10 years, and then 1% for the next 10 years and 1.5% by 2030, which will be 30% of the bridge cost in the first 30 years of operation of the bridge. In accordance with existing domestic and foreign standards, the durability of such engineering structures as a bridge or tunnel should be at least 100 years (according to European standards—at least 120 years, the recommended example is Oresundsky combined bridge tunnel). Comparison of the construction of bridges and tunnels according to national standards is presented in Table 2. 6. An important problem in the construction of the tunnel with the use of the TFMS on the sub-section of the Nevelsky Strait is ensuring the safety of construction. Table 2 Comparison of bridges and tunnels Indicators

Bridge structures (span structures) using reinforced concrete and steel

Tunnel structures (reinforced concrete tunnel lining blocks)

Standard lifetime of the structure

50–100 years SP 35.13330.2011 bridges and pipes. Updated version of SNiP 2.05.03-84 * (with a change in N 1)

Over 100 years SP 122.13330.2012 railway and road tunnels. Updated edition SNiP 32-04-97 (with a change in N 1)

Construction cost

100%

115%

Maintenance and repair during the first 50 years of operation

50% of the initial cost, length and material of the superstructure and the pylon

30% of original cost

The final cost, taking into account operating costs in the 100 year period

150%

145%

Assessment of economic efficiency depending on the life cycle, from 100 to 120 years

25%

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Despite the known cases of breach of the hermeticity of a tunnel under construction (e.g., during the construction of the Great Belt tunnel in Denmark), shield sinking is a fairly safe way to construct a tunnel if the production technology is followed and the geotechnical conditions at the construction site are properly taken into account.

3.1 Analysis of the Cost of Construction of Transport Crossings

$/m2

The cost of building unique cable-stayed bridges in the Russian Federation is no higher than the average observed in most foreign countries, but it is not possible to achieve technical and economic indicators with a significant reduction in the cost of building bridges in China. The total cost of the project implementation according to the adopted analog—Oresund combined bridge-tunnel will be no more than 10,101 $/m2 (Fig. 5). When choosing a construction project for a suspension bridge, this will be the first experience for Russia in implementing bridges with this design 18000 16000 14000 12000 10000 8000 6000 4000 2000 0 Tianxingz Yeongjong hou Bridge, Bridge, China, China, combined combined movement, movement, 2000 2009 Main span, m $/m2 Total length

504 1054 4657

300 873 4420

Akashi Kaikyō Bridge, Japan 1998 1991 15485 3911

Øresund Øresund Bridge, тоннель, Denmark Denmark and and Sweden, Sweden, combined combined movement, movement, 2000 2000 490 5882 10101 4050 7845

Fig. 5 Main technical and economic indicators of two-tier cable-stayed and suspension bridges with a rigid steel truss and tunnel

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scheme, but harsh cold conditions impose significant restrictions on the construction and operation of a bridge in a remote region. At the moment, the cost of contract work under state contracts for central artificial structures of ring roads of the two capitals of the Russian Federation is from $1 to $3 thousand per m2 , depending on the intersection conditions, construction and material of the span, installation method with reference and technological windows in the traffic schedule trains. In conclusion, I would like to note that the analytical review and comparison of analogs of large investment projects in terms of technical and economic indicators should include all the positive effects of the development of an international transport system. The implementation of megaprojects leads to the emergence of general economic effects due to the positive impact on employment, labor productivity and the pace of regional development, and this, in the opinion of the authors, is one of the ways to overcome the crisis. A good example is the socio-economic effect of the Oresund transport transition in 2010. Sweden saved e175 million in unemployment benefit payments, thanks to increased employment opportunities for previously unemployed citizens [11].

4 Conclusions 1. The current economic and political situation requires the intensification of work to create a permanent transport transition between Sakhalin Island and the mainland part of the Russian Federation. 2. The implementation of an ambitious large-scale project, which in the long run can have a positive impact on the socio-economic growth rates of Sakhalin, for the whole of Russia and the countries of the East Asian Partnership, is recommended to be formed in a new institutional environment based on partnerships of the state with private business. 3. Currently, Russia and abroad have accumulated considerable successful experience in the design and construction of cable-stayed (suspension) bridges and underwater tunnels (both road and rail) under difficult engineering and geological conditions; unique specialized equipment has been created; trained and trained engineers and workers for unique work. 4. Practically all foreign countries, when crossing large water barriers, when comparing bridge and tunnel variants, prefer different types of tunnel crossings and, in some cases, a combined solution (tunnel-bridge). The choice of the optimal option should be carried out on the technical and economic indicators of total, construction and operating costs, including the payback period, the cost of emergency situations, seismic safety and environmental protection for the estimated period of operation. 5. Mastering innovations that reduce economic construction costs, increase the durability and service life of structural elements of a tunnel structure (using high-strength concrete), using high-strength steel for a bridge structure, with an

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estimated lifetime of 120 years and with preliminary savings operating costs by 25%, in comparison with a bridge structure with metal spans. 6. Due to the lack of key documents, a legislative decision is needed for the implementation of rationing in the transport field in the following areas: development of special technical conditions, a single regulatory document regulating at the same time issues of life cycle contracts, warranty period, quality and completeness of engineering and geological surveys, calculations, design, production of works and operation of transport transition in seismically hazardous zones. 7. BIM technology, including monitoring and interpretation of the results obtained, must be used in the interaction of all stakeholders and participants: the customer, the operating organization, the design engineer, the builders, etc., examples of western counterparts.

References 1. Oresunds bron Homepage, https://data.oresundsbron.com. Last accessed: 2018/12/20 2. Kirkland CJ (1986) The proposed design of the English Channel Tunnel. Tunn Undergr Space Technol Inc Trenchless 1(3–4):271–282 3. Molenaar VL (1986) Immersed tube tunnelling offshore: execution of immersed tube tunnelling projects under offshore conditions, based on studies for the euroroute fixed channel link proposal. Tunn Undergr Space Technol Inc Trenchless 3–4:289–296 4. Uchida (1985) Takashige Plan, technology and future prospects for the Seikan tunnel. Civ Eng Jpn 24:14–23 5. Martire G, The development of submerged floating tunnels as an innovative solution for waterway crossings. Diss., Ph.D. Engineering, Italy, 316 p 6. Peroni M (2008) New design idea for a very long suspension bridge: In: Eleventh East AsiaPacific conference on structural engineering and construction, EASEC-11 7. Hao D, Qinxi L, Shuping J, Ke L (2016) Enlightenment to floating tunnel of existing typical submerged tunnel. Procedia Eng 166:355–361 8. Siviero E, Ben Amara A, Guarascio M, Bella G, Zucconi M, da Fonseca AA, Slimi K (2015) Towards a global world multi-span large bridges. In: Proceedings of the international conference on multi-span large bridges 2015, TUNeIT, Portugal, pp 215–222 9. Private Participation in Infrastructure Database Home page, http://ppi.worldbank.org. Last accessed 2018/12/21 10. Kulagin NI, Maslak VA, Bezrodny KP, Lebedev MO (2018) On the transport passage to Sakhalin Island. Undergr Horiz 18:38–43 11. Oresunds statistik och analyser Home page, http://www.orestat.se. Last accessed: 2018/12/21

Analysis of Changes of Track Upper Structure Technical Condition and Its Operation Costs in Regions with Long Winter Period for Different Types of Rail Fastenings Vladimir Beltiukov, Andrey Andreev and Anna Sennikova Abstract The article discusses the problems of the effect of the winter period duration on indicators of railway track condition and its operation costs in regions with a long winter period. The analysis of railway track structure characteristics carried out for railway sections with different winter period durations. Effectiveness evaluation uses failure rate prediction and LSC calculation, using the model based on reliability analysis. The operation costs depending on the duration of the winter period are calculated. Keywords Railway track structure · Rail fastening · Lifecycle costs · Winter period duration

1 Introduction One of the operational features of Russian railways is a long winter period. These features present challenges in railway track maintenance, such as inability of track surfacing due to ballast freezing, the need for snow defense and removal of snow, blow-ups due to roadbed frost. All this causes fault accumulation in the track geometry and track superstructure elements. As a result, track work’s amounts and costs are increasing.

1.1 Brief Analysis of Research on This Issue Most scientific studies of track structure faults accumulation explore relationships between operating time or tonnage and intensity the fault accumulation. Various functional dependencies are applied to these relationships. V. Beltiukov (B) · A. Andreev · A. Sennikova Railway Track Department, Emperor Alexander I St. Petersburg State Transport University (PSTU), 9 Moskovsky pr., 190031 Saint Petersburg, Russian Federation e-mail: [email protected]; [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_27

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The shortcoming of applying of most simple functions is that they describe the behavior of the track in a limited set of operating conditions. Moreover, attempts to apply these functions for another operating conditions or structure lead to results that do not correspond with the actual technical condition of the track. Which model to choose for descripting the intensity of accumulation of deformations—this is an important question. Shakhunyants [1] and Shulga [2] developed the first models for track maintenance costs, as simplified functional dependencies. Mishin [3, 4] developed the mechanism for predicting the condition of the track. In addition, we can mention the works of Kumar [5], as well as works on the railway track structure lifecycle cost. The most important is the study of the physical nature of cost changes depending on time and tonnage. Shulga [2] proposed a linear dependence on time. Laptev [6], Smirnova [7], Popov [8] described amount of work on the tonnage by a power dependence. V. Shulga later proposed, instead of linear, a more complex dependence of labor costs on tonnage [9]. When analyzing the labor costs of track maintenance, Stelmashov [10] proposed to take into account both the number of years from the moment of installation and the tonnage. In studies of Kondakov [11], the time factor was taken into account by table values. In the methodology of Andreev [12–14], track degradation was taken into account through the increasing of the track gauge irregularities size. But in most cases, the costs described by the following dependence on time f = a + bt n where f is maintenance costs; t is period after renovation; a is constant part of costs; b is the time-based parameter. Such form of the dependence of maintenance-of-way cost on time or tonnage was obtained by G. Shakhunyants, V. Stelmashov, V. Shulga, and V. Yanin in their studies. The index n in most studies is close to 2. The effect of the winter period duration in studies of Shakhunyants, Shulga, and Andreev is taken into account with special multiplier.

2 Calculation of Average Maintenance-of-Way Costs To analize changes of indicators of railway track condition, statistical studies were conducted. These studies were carried out in regions with rigorous climate, with different duration of winter period. As a result of the studies, the influence of the type of rail fasteners on the costs of maintaining the track was determined.

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2.1 Railway Track Superstructure Lifecycle Costs Model To determine the cost of maintaining the track, we used a special model of track superstructure changes during the life cycle [15, 16] and the method of calculating of the lifecycle cost [17, 18]. The most correct method for determining of technical objects and systems efficiency is lifecycle cost analysis (LCC). Life cycle includes all processes from the moment of object concept creation concept through the stages of determination the requirements, design, object creation, its operation to its utilization. For the first time, the theory of the cost of life cycle was applied to the railway track by such scientists as Coenraad and Zoeteman [19–21]. Patra [22] added the RAMS methodology to the calculation of the railway track lifecycle cost. JSC “Russian Railways” (RZD) also uses RAMS methodology for LCC calculations. RZD has developed its own methodology «URRAN» under the supervision of Vice-President Gapanovich [23]. Life cycle of the superstructure includes a period from one major overhaul (renewal, modernization, renovation, reconstruction) to the next. The standard frequency of repairs is specified by «Specifications for the reconstruction (modernization) and repair of railway track» [24]. The purpose of the LCC calculation is resource assignment optimization. RAMS and URRAN methodologies use two different methods of calculation: the lifecycle cost for object that is replaced, and LCC for objects continuing its operation. For both methods, lifecycle cost is calculating with techniques of forecasting, comparison wa variants, choice of optimal methods for life cycle continuing. Therefore, cost estimating for all lifecycle phases is the task, which allows assignment resource managing throughout the life cycle. Maintenance-of-way costs were calculated using the model of behavior of an object at all lifecycle phases. In terms of economics, this means that life cycle of railroad superstructure is the sum of various types of cost. Every type characterizes its own phase of life cycle. In many cases, railway superstructure conditions database may be insufficient. So, maintenance-of-way cost calculations must be performed in several different ways. The first way is using simulation of rolling stock and track superstructure interaction. The second way is using results of observations and tests of existing railway track, with measurement of interaction parameters. The third way is using results of real maintenance-of-way costs on the operated railway tracks. To solve this and other problems of optimizing the maintenance of railway tracks, the special track behavior model was created in PSTU [15, 16]. This model describes changes in track conditions between overhauls. The model based on reliability and costs calculations. The model of track behavior between repairs can be described by the following expression: F=

  C x k + Bx + A 1 − e−( e ) x

(1)

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A, B, C, and k are of track faults accumulation parameters, depending on tonnage; x is tonnage, mln gross tons; y is the average amount of track failures per km. It is necessary to define parameters A, B, C, and k for predicting changes in track technical condition.

2.2 Data for Analysis The analysis was carried out based on statistical processing of databases on the condition of the track on railroads with a winter period of five or more months. The data for the analysis was collected from databases of automated control systems. For the analysis was taken the data for railway sections with the same track construction: new heat-strengthened R65 rails, continuous welded track, concrete sleepers, crushed stone ballast, and different types of rail fasteners: KB, ARS, and ZhBR. According to the collected data, the dependency parameters were calculated for the superstructure technical state indicators. For statistical processing, Russian Railways databases were taken from 2007 to 2016. The volume of databases for so many years is about 15 million points, that is, a million kilometers in total. The entire length of railway track was divided into sections with the same operating conditions and with the same track structure. Thus, a large number of dependencies were obtained, which were used for approximation analysis using the least squares method, and the parameters of dependencies were calculated for expression (1).

2.3 Data Processing Results The following are the results of the analysis of the number of faults requiring track alignment in the profile and level, depending on the tonnage (Figs. 1, 2, 3, 4, 5, and 6). The following notation is used in the graphs: ALL—average network dependencies for all sections of the continuous track with reinforced concrete sleepers. APC, KB, ZhBR—dependencies for sections with ARS, KB, ZhBR fasteners. Approx—dependencies approximated in accordance with the accepted model. Then, calculation was performed for the prediction of deterioration processes depending on tonnage, and forecasting the volumes of track works for every year. The results of track condition indicators and maintenance-of-way costs calculation for track superstructure with different types of rail fastenings are shown in Table 1.

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Fig. 1 Dependence of the average number of track gauge width faults on the tonnage on continuous railway track sections in areas with a winter duration of 5 months

Fig. 2 Dependence of the average number of track level faults on the tonnage on continuous railway track sections in areas with a winter duration of 5 months

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Fig. 3 Dependence of the average number of track gauge alignment faults on the tonnage on continuous railway track sections in areas with a winter duration of 5 months

Fig. 4 Dependence of removal of failed rails on the tonnage on continuous railway track sections in areas with a winter duration of 5 months

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Fig. 5 Dependence of removal of failed sleepers on the tonnage on continuous railway track sections in areas with a winter duration of 5 months

Fig. 6 Dependence of the percentage of defective rail fastenings on the tonnage on continuous railway track sections in areas with a winter duration of 5 months

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Table 1 Results of calculation of track condition indicators and maintenance-of-way costs Indicator (units meas.:)

Average number of track gauge width faults (pcs/km per year)

Average number of deviations of profile and level (pcs/km per year)

Average number of deviations of alignment in the plan (pcs/km per year)

Removal of failed rails (pcs/km)

Percentage of defective fastenings (%)

Percentage of defective sleepers (%)

MoW costs (RUB/km per year)

ARS

1.81

2.86

0.64

0.22

0.63

0.03

236,330

KB

0.81

2.87

0.48

0.30

1.97

0.07

278,495

ZhBR

0.69

3.53

0.73

0.46

2.09

0.10

317,421

The dependence of the direct costs of maintenance of way works on tonnage for track with different types of rail fastenings is shown in Fig. 7. Analyzing the calculation results (see Table 1), we can note that under conditions of long winter and high rigidity of track, the best indicators of maintaining costs show ARS fastening; although this fastening shows large amount of track gauge width faults. The number of other damages is small. Therefore, it is necessary to consider that for conditions of a long winter this fastening shows itself in the best way, it has a rational rigidity and ensures minimal maintenance costs (see Fig. 7).

Fig. 7 Dependence of the direct costs of maintenance of way works on tonnage on sections of the continuous welded track with concrete sleepers in areas with a winter duration of 5 months

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KB fastening shows average results. On the way, these fastenings ensure the minimum of deviations of alignment in the plan. ZhBR fastening of modification, that was laid in track during the years of studying, showed the worst results for all types of faults, except the gauge width. Therefore, ZhBR shows the maximum cost of maintaining. Now, manufacturers of ZhBR fastening are introducing a new type of modernized fastening—ZhBR-65-PShM, that should provide optimum rigidity of the track and minimal maintenance costs, including winter period. According to the results of the study, the best rail fastenings for sections of the track, which are in harsh winter conditions, in terms of the minimum cost of the maintenance of way is the ARS anchor fastening.

References 1. Shakhunyants G (1976) Work of track and its maintenance costs. In: Proceedings of MIIT, vol 491. MIIT, Moscow, pp 3–67 2. Shulga V (1965) The influence of operational factors, the capacity of the upper structure and its term of life on the track maintenance costs. In: Proceedings of CNII MPS, vol 182. Transport, Moscow, pp 136–197 3. Mishin V (2004) Probabilistic-statistical analysis of track bendings and twists. Vestnik VNIIZT № 4, pp 31–36 4. Mishin V (2011) Predicting of track condition indices. Problems and solutions. Railway Track and Facilities (Put i putevoe khozyaystvo), № 7, pp 2–6 5. Kumar S (2006) A study of the rail degradation process to predict rail breaks. Luleå University of Technology, Luleå 6. Laptev V (1978) Volumes of aligning works during maintenance of way. In: Proceedings of MIIT, vol 615. MIIT, Moscow, pp 152–160 7. Smirnova M (1985) Maintenance of way planning. In: Proceedings of MIIT, vol 760. MIIT, Moscow, pp 99–107 8. Zolotarsky A, Popov S (1950) Tonnage between repairs norms for different track structures. VNIIZT, Moscow 9. Shulga V (1967) Strictly observe the frequency of repairs. Railway Track and Facilities (Put i putevoe khozyaystvo), № 6, pp 6–9 10. Stelmashov V, Antonov F (1968) Track maintenance costs. In: Proceedings of CNII MPS, vol 357. Transport, Moscow 11. Kondakov N (1977) Track maintenance organization based on the optimization of labor costs. NIIZT, Novosibirsk 12. Amelin S, Andreev G (1986) Track construction and maintenance. Transport, Moscow 13. Andreev G (1974) Determining of volumes of track works. Transport, Leningrad 14. Andreev G, Danilov V, Marushko S, Solovyov V (1984) Planning and organization of track maintenance. LIIZT, Leningrad 15. Beltiukov V (2013) Selection of the optimal way construction, depending on the life cycle cost. In: Problems of interaction track and rolling stock: Proceedings of international scientific conference. DTIS, Dnepropetrovsk (Ukraine), pp 60–61 16. Andreev A (2013) Methods of determining the life cycle cost of the railway track, taking into account forecasting technical condition of the track. In: Conference «XXI Century Track». PSTU, St. Petersburg, pp 188–193 17. Beltiukov V (2011) Optimization of medium-term plans of railway track repair. Russ Fed Transp 3(34):71–74

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18. Simonyuk I (2013) Model of railroad track behavior for prediction of track conditions at the stage of long-term planning. In: Conference «XXI Century Track». PSTU, St. Petersburg, pp 193–202 19. Zoeteman A, Coenraad E (2000) Evaluating track structures: life cycle cost analysis as a structured approach. Delft University of Technology, Delft 20. Zoeteman A (2001) Life cycle cost analysis for managing rail infrastructure. Concept of a decision support system for railway design and maintenance. Eur J Transp Infrastruct Res 4:391–413 21. Zoeteman A (2004) Railway design and maintenance from a life-cycle cost perspective: a decision-support approach. TRAIL Research School, Delft 22. Patra A (2007) RAMS and LCC in rail track maintenance. Luleå University of Technology, Luleå 23. Gapanovich V (2013) Based on the optimization of the life cycle cost. Railw Transp (Zheleznodorozhny transport) 6:26–34 24. Specifications for the reconstruction (modernization) and repair of railway track (№ 75p). JSC «Russian Railways» (2013)

Experiments of Autonomous Vehicles Running at a Test Track, and Future Prospects Kazunori Munehiro , Naohisa Nakamura and Masaya Sato

Abstract In order to grasp the influence of the running of autonomous vehicles on road, we conducted an experiment reproducing a situation of autonomous vehicles and general transportation vehicles sharing roundabout and straight section of the Tomakomai Test Track, and gathered basic data concerning the running performance and a subjective evaluation. Ten regular drivers took part as subjects in this experiment and enabled the obtaining of results indicating that constant safety was secured for the running of an autonomous vehicle at the roundabout and straight section. In addition, road structure and management considering the road hierarchy and selfdriving system level were examined. According to the road hierarchy, the adoption of roundabout as a connection method was also proposed. Keywords Autonomous vehicle · Subjective evaluation · Crossing method · Road hierarchy

1 Introduction In recent years, research and development, and public road demonstration experiments concerning autonomous vehicles have been actively conducted in various places, such as Japan, the USA, and Europe [1–3]. In Michigan State of the USA, self-driving testing is promoted through efforts in three layers of “prior art development/academic research” (Mcity), “verification and certification of practical technology” (ACM), “public road examination” (MDOT connected corridor) [4]. The Wyoming State Transport Authority in the USA has undertaken research and development on cooperative systems of road managed vehicles, such as snow removing vehicles and roads, i.e., connected vehicles [5].

K. Munehiro (B) · N. Nakamura · M. Sato Traffic Engineering Research Team, Civil Engineering Research Institute for Cold Region (CERI), PWRI, Hiragishi 1-3-1-34, Toyohira-Ku, Sapporo 062-8602, Japan e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_28

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Affiliated ministries and agencies, automobile manufacturers, academics, automobile-related organizations, etc., participate in Japan’s strategic innovation creation program (SIP) automatic travel system project [1]. Under the program, efforts to commercialize the system and to conduct large-scale demonstration experiments and the like have been undertaken. The ministry of land, infrastructure, transport, and tourism conducted “Demonstration Experiment for Self-Driving Services Based on Roadside Stations (Micho-no-Eki) in Rural Areas” in FY 2017 [6]. Also, as the largest number of automotive test courses in the country are located in Hokkaido of Japan, a large number of test courses by automobile manufacturers and other private companies, and demonstration experiments on public roads, have been undertaken [7]. Peter F. Sweatman worked on organizing the requirements of infrastructure to cooperate with autonomous vehicles [8]. Liuhui Zhao et al. used a traffic flow simulation to reproduce the state in which autonomous vehicles are mixed in general transportation vehicles at roundabouts [9]. However, it has not been made clear that the results of experiments with running autonomous vehicles focus on the structure of intersections and road management. In Japan, the Road Traffic Act was revised in 2014 and the introduction of roundabouts became possible. As a result, roundabouts are spreading in Japan as a new intersection structure that is safe, environmentally friendly, and resistant to disasters. However, there have been no studies on real running of autonomous vehicles at roundabouts so far. Therefore, at the compact single-lane roundabout on the Tomakomai Test Track, we simulated driving tests by reproducing the condition of autonomous vehicles and general transportation vehicles sharing the road. Based on the promotion of research and development on domestic and overseas autonomous vehicles and the spread of roundabout intersections, the purpose of this research is to clarify the following: (1) Subjective evaluation of drivers under the circumstances of autonomous vehicles and general transportation vehicles sharing a roundabout; (2) Proposal of road structure and management in consideration of road hierarchy and the self-driving level.

2 Outline of Self-driving Technology 2.1 The Stage of the Self-driving System A self-driving system is a system in which the machine performs all or a part the recognition, judgment, and operations normally performed by the driver. Self-driving techniques such as automatic braking, lane-keeping assistance system (LKAS), and adaptive cruise control (ACC) have already been installed in some commercial vehicles. In other words, partial automation of recognition, judgment,

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Table 1 Stage of the self-driving system

and operations normally performed by the driver is introduced. Currently, the stages of the self-driving system are classified in Table 1.

2.2 Vehicle Position Estimation Technique The technique for estimating own vehicle position in order to realize self-driving is required to be very accurate. The vehicle position estimation technique requires macro position estimation on the travel route and micro position estimation of the lane position when traveling on a road with multiple lanes. The following are examples of vehicle position estimation techniques [10]. (1) GNSS (Global Navigation Satellite System) (2) Inertial Navigation (3) Magnetic Sensor.

2.3 Surrounding Detection Technology The ambient detection technology is a technology to recognize 360° around the subject vehicle up to the necessary distance by utilizing sensors in combination. Examples of ambient detection techniques include the following. (1) Visible Camera (2) Millimeter-wave radar (3) LIDAR (LaserImaging Detection and Ranging).

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3 Experiment on Tomakomai Test Track 3.1 Experiment Site At the roundabout (outside diameter: 27 m) of the Tomakomai Test Track (extension of the circumferential road L = 2.7 km), test vehicle (autonomous vehicle) equipped with a self-driving function were run together with general vehicles. The state was reproduced and the actual run was made (Fig. 1). The outer diameter of the target roundabout is 27 m. The experiment was conducted on February 6, 2018. For general vehicles, ten commercial vehicles were rented, and the inflow and outflow of roundabouts were repeated at random. Autonomous vehicle repeated the inflow and outflow of roundabouts while the general vehicles were running. Autonomous vehicle started, steered, and stopped itself from before the roundabout entering to after running. Two automobile technicians were on board the autonomous vehicle with no driving operation. In addition to the roundabout, a running test was conducted on a single-track part (straight section) located on the outer circumferential road of the test track, and the state in which a general vehicle follows an autonomous vehicle was reproduced (Fig. 1).

3.2 Subjective Evaluation As drivers of general vehicles, ten regular drivers who have a driver’s license for regular vehicles participated. General drivers responded to questionnaires after driving around a roundabout (intersection) and straight section (single-track section) also shared by autonomous vehicles. The authors explained the purpose of the experiment in advance to the drivers and obtained written consent.

Autonomous Vehicle

General Vehicles

Autonomous Vehicles

Fig. 1 Outline of experiment (left: roundabout, right: straight section)

General Vehicles

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The questionnaire contained a seven-scale subjective evaluation (irritation, safety, ease of driving) of driving on a road shared by self-driving and other cars. Regarding irritation, the scale consists of 1: quite irritated to 7: not irritated at all. Regarding safety, the scale is from 1: very dangerous to 7: very safe. Regarding the ease of running, the scale is from 1: hard to drive to 7: very easy to drive.

4 Experimental Results 4.1 Subjective Evaluation Under Conditions in Which Autonomous Vehicles Share a Road with General Traffic In the general traffic, we reproduced the condition of mixed autonomous vehicle and carried out a running test. The traveling section was roundabout and single-track part (straight section). The running speed of the autonomous vehicle was about 10– 20 km/h in both sections. Similarly, the rate of the general traffic as well, was about 10–20 km/h. From the results of the questionnaire given to the general drivers who participated in the experiment, we compiled the subjective assessment of irritation and obtained the data shown in Fig. 2. The subjective evaluation of irritation is shown for the roundabout and the singletrack part. According to it, the feeling of irritation at the roundabout only slightly increased from the average value. In other words, it seems that the ten general drivers who participated in the experiment did not feel particularly irritated even at the roundabout even when the autonomous vehicles were sharing the road with the general transportation vehicles. Next, based on the answers from drivers, the subjective assessment of safety was compiled and Fig. 3 was obtained. As for this evaluation value, about 5 was obtained as an average value for both the roundabout and single-track parts. That is, at the roundabout, it was found that the safety was somewhat higher.

Fig. 2 Subjective irritation assessment value

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Fig. 3 Subjective safety assessment value

Fig. 4 Subjective running assessment value

Also, the subjective evaluation of the ease of driving from the answer results by general drivers was tabulated. Figure 4 was obtained about the evaluation value, and about 5 was obtained as an average value for both roundabout and single-track parts. That is, the ease of driving at the roundabout is relatively high. Comparing the single road part with the roundabout, the evaluation was slightly higher in the single-track part.

5 Toward Structure and Management Considering Road Hierarchy and Self-driving Level 5.1 Road Functions and Hierarchies A road is a fundamental social capital that supports all kinds of socio-economic activities. In addition to transportation functions for people and cars, roads accommodate public utility facilities such as water supply and sewerage systems and electric cables, and space for daylighting, ventilation and disaster prevention. Furthermore, in urban areas, a road is a key facility that constitutes the framework of the cityscape. This

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Table 2 Proposal of road hierarchy classification (in case of Hokkaido, Japan)

multi-faceted function of the road contributes to public welfare and brings great benefits to the people’s lives. Of the functions of a road, paying attention to the traffic function, the connecting scale is taken on the vertical axis and the road type is taken on the horizontal axis. A case study on Hokkaido in Japan and a road hierarchy classification was tried, and shown in Table 2 [11]. We also examined the connection style of roads. The connection method of the hierarchies A and B with large contact scales is based on a three-dimensional intersection. For hierarchies C, D, and E below the medium scale of the connecting scale, signal intersections, roundabouts, and non-signal intersections are allowed as intersecting formats [12]. For other roads (such as private roads), we propose making non-signal intersections into intersecting formats. A draft proposal of the connection method according to the road hierarchy is shown in Table 3.

5.2 Required Road Structure and Management When considering the inclusion of autonomous vehicles, we examine what kind of impact there is on-road structure/management. The contents of self-driving according to the road hierarchy and the draft proposal of required road structure and management were made. Viewed by road hierarchy, the following is considered. (1) Inter-regional/inter-regional connection: Hierarchies A and B

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Table 3 Proposal of a connection method according to the road hierarchy (in the case of Hokkaido, Japan)

These hierarchies can be applied in logistics such as the running of compact cars and trucks on a highway (car-exclusive road). According to the lane-keeping assistant system (LKAS) and active cruise control (ACC) already installed in commercial vehicles, follow-up running, that is, Level 2 autonomous running has been realized. It is expected that the entire system, including Level 3 and Level 4, will be responsible for driving tasks in the future. These autonomous functions are achieved primarily based on linear recognition by the lane markings on roads and recognition of the behavior of forward vehicles. Therefore, it is also expected that road appendages and signs will be consolidated and simplified in the future. (2) Contact between municipalities: Hierarchy C In the future, it is expected to realize a Level 2 self-driving system. Road structure and road management is required for automatic traveling technologies, such as LKAS and ACC, to function. In the road structure, it is necessary to consolidate and simplify road appendages and signs. Also, there are various intersection types (multi-limb intersections, deformed intersections, etc.) on actual roads, which are accompanied by difficulty in autonomous running. In order to overcome this, patterning and standardization of intersection types are required. By converting a deformed intersection into a roundabout, the intersection forms of this hierarchy can be gathered into two types: a crossed crossing and a roundabout. Furthermore, certain levels are required for road management, such as snow removal and weeding. (3) Contact within municipalities: Hierarchies D and E

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Fig. 5 Proposal for a road network considering road hierarchy and self-driving level

An autonomous traveling system of this hierarchy is assumed to be introduced to substitute for public transportation and the like. Standardization of the intersection structure of the target section and appropriate road management are required. (4) Dedicated space: Hierarchy F The self-driving system in this hierarchy is assumed to be applied when space is limited, such as at sightseeing spots and parks. Because of the limited space, it seems possible to realize Level 4 self-driving, which carries out all the operation tasks of the entire system. Figure 5 shows a proposed road network considering the above-mentioned road hierarchy/self-driving level.

6 Conclusion Basic experiments on running of autonomous vehicles at roundabout of the Tomakomai Test Track revealed the following. (1) At the roundabout, we conducted a subjective assessment of drivers on a road shared by autonomous vehicles and general transportation vehicles. Driver’s sense of irritation, safety, and ease of driving gained a high evaluation. The acceptability of autonomous vehicles at roundabouts is considered to be high. (2) In consideration of running an autonomous vehicle, we extracted tasks from the structure and management side of the roundabout. It was found that it is necessary for an autonomous vehicle to be able to always recognize pavement markings (lane marks) and signs regardless of day and night or weather.

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(3) We proposed a road network when considering the road hierarchy and selfdriving level, and suggested a way for the required intersection structure. Standardization of intersection formats is required when considering the mixing of autonomous vehicles on general roads, such as road hierarchies C, D, and E. The compact single-lane roundabout is a friendly structure for both autonomous vehicles and general vehicles. Therefore, promotion of compact single-lane roundabouts is desired in this road hierarchy. We intend to deepen our knowledge about the impact on the structure and management of road infrastructure based on the progress of self-driving system technology in the future. For example, we are aiming to apply it to snow removal vehicles of self-driving technology. We are planning to collaborate with the relevant road managers, such as the Hokkaido Development Bureau of the Ministry of land, infrastructure, transport and tourism, Hokkaido Government, municipalities, and private car makers and other relevant organizations. Future Plan Based on this paper, the basic arrangement of the relationship between the autonomous vehicle and the road hierarchy/structure and the self-driving level was carried out. Currently, our research group applied this technology and started research on driving support for snow removing vehicles in cold snowy areas. In the future, we plan to make advanced application research on snow removal vehicles (Photo 1). Acknowledgements I express my gratitude here for the cooperation we received from participating companies in the joint research of “Driving support for snow removal vehicles by utilizing selfdriving technology and road structure and management” in carrying out this research.

Photo 1 Snow removal truck

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References 1. Japanese Government Cabinet Office. Strategic Innovation Creation Program (SIP) Automatic Travel System Research and Development Status. http://www.kantei.go.jp/jp/singi/ keizaisaisei/miraitoshikaigi/4th_sangyokakumei_dai3/siryou9.pdf 2. Van Arem B (2017) Dutch automated vehicle initiative, taking the dream of automated driving to reality. In: Proceedings of 97th TRB Annual Meeting, Washington D.C. 3. Blythe P (2018) Progress with Automated Vehicles in the UK. In: Proceedings of 97th TRB Annual Meeting, Washington D.C. 4. Mcity: Mcity Test Facility. https://mcity.umich.edu/our-work/mcity-test-facility/ 5. Wyoming DOT: Wyoming DOT connected vehicle pilot. https://www.its.dot.gov/pilots/pdf/ CVP_WYDOTSystemDesign_Webinar.pdf 6. MLIT of Japan: demonstration experiment of automatic driving service based on Michino-Eki in the inter-mountains area. http://www.mlit.go.jp/road/ITS/j-html/automated-drivingFOT/index.html 7. Ministry of Economy in Japan, Trade and Industry Hokkaido Industry Bureau: Toward Realization of Productivity Revolution ‘Promotion of Implementation of AI · IoT in Community’. http://www.hkd.meti.go.jp/hokim/20171219/seisanseikakumei.pdf 8. Sweatman PF (2015) Connected infrastructure to support automated driving. In: Proceedings of 94th TRB Annual Meeting, Washington D.C. 9. Zhao L, Malikopoulos AA, Rios-Torres J (2018) Optimal control of connected and automated vehicles at roundabouts. In: Proceedings of 97th TRB Annual Meeting, Washington D.C. 10. Yuki Kitsukawa et al (2017) Field testing of self-diving vehicles: lesson learned on localization, pp 48–53. IATSS Rev. 42(2) 11. Munehiro K et al (2008) Toward safe, comfortable in northern road. Traffic Eng. 43(4):50–56 12. Oguchi T (2015) Appreciation of automated driving based on the hierarchy of vehicular roads. IATSS Rev. 40(2):25–32

Stress–Strain State of Railway Embankment with the Use of Mineral Geoecoprotective Material Ivan Kozlov

Abstract The aim of the work is to obtain a computational justification for the use of mineral geoecoprotective material—foam concrete—in the construction of the railway embankment in cold regions. Finite element estimates the stress–strain state of the railway embankment without foam concrete, and with the plate of foam concrete of various thicknesses. The article contains recommendations for the design of geoecoprotective structure in the railway subgrade with the use of foam concrete. The obtained results can be used in the design of new and reconstruction of existing railways as a justification for the possibility of using the proposed geoecoprotective design as part of the railway roadbed. Keywords Stressed-deformed state · Railway embankment · Subgrade · Mineral geoecoprotective material · Foam concrete

1 Introduction In order to detoxify heavy metal ions, preserve and conserve natural resources, as well as strengthen the main site of the subgrade, a layer of mineral geoecoprotective material—foam concrete—is introduced into the structure of the embankment. On the basis of the works [1–5] on the use of geoecoprotective properties of foam concrete by the absorption of heavy metal ions in building structures, this article proposes a design justification (determined by the stress–strain state) of the subgrade using a foam concrete plate with an average density of 400 kg/m3 . It was meant that the compacted sand–gravel mix, on the site of which the plate is provided, has an average density of 2000 kg/m3 . A fivefold material saving by mass is predicted [6–10].

I. Kozlov (B) Emperor Alexander I State Transport University, St. Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_29

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2 Initial Data for Calculations The 5 meters width of the plate was taken in order to clean the flowing (from rolling stock, rail, sleepers, and ballast) water contaminated with heavy metal ions, as well as to provide a more equal load distribution from the rolling stock and the superstructure over a large area, which should reduce the stress–strain state of the underlying soil [11–14]. According to sources [4, 6], for the disposal of heavy metal ions for the service life of the upper structure of the track between major repairs (10–15 years on average), there is enough a 10-cm-thick foam concrete plate. To find out the thickness of the plate with the most advantageous version of the stress–strain state, four series of calculations were made: without a plate, with a plate of 10, 20, and 30 cm thick. Deformations were evaluated on the edge and middle of the foam concrete plate. Stresses—in characteristic sections: in the near-rail zone, where the largest force effect occurs and in the horizontal plane under the plate (in the points under the axis, rail, and edge) at a depth of 40 cm for the validity of the experiment. The design scheme of the original embankment (without foam concrete) is given according to [15], Fig. 1. The three-layer mound consists of sand–gravel mix, brown loam, and gray loam. At the base lies brown sandy loam. The steepness of the embankment slopes is standard (1:1.5).

Fig. 1 The design scheme of the original embankment. 1—crushed stone; 2—sand and gravel mix; 3—brown loam; 4—gray loam; 5—brown sandy loam. Forces are in tons. Dimensions are in meters

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Table 1 Physical and mechanical characteristics of materials №

Soil title

Elastic modulus (MPa)

Poisson’s ratio

Specific weight (kN/m3 )

1

Crushed stone

400

0.23

22

0

40

2

Sand and gravel mix

120

0.28

19

1

30

3

Brown loam

50

0.35

20

28

22

4

Gray loam

50

0.37

20

28

22

5

Brown sandy loam

45

0.31

20

14

25

Coupling (kPa)

Angle of internal friction (°)

Fig. 2 Structural scheme of the mound with a foam concrete plate of various thicknesses

The characteristics of the soils used in the calculations are given in Table 1. Structural scheme of the mound with a plate of foam concrete of various thicknesses is shown in Fig. 2. The elasticity modulus of foam concrete and Poisson’s ratio is taken from reference data and is 5000 MPa and 0.17, respectively [16, 17]. The design model of the mound with a plate of foam concrete of various thicknesses is shown in Fig. 3. All calculations were carried out by the finite element method in the certified software complex FEM-models, developed in LLC PI Georeconstruction, with the direct participation of Paramonova [18–21].

3 Result of Calculation The calculation of the vertical displacements of the main site of the roadbed (Table 2) showed that the plate, with a thickness of 10 and 20 cm, has the same minor distribution (leveling) effect, and it reduces the vertical displacement along the structure axis by 0.2 mm and increases along the edge by 0.5 mm. A plate with a thickness of 30 cm works better—reduces vertical displacements along the structure axis by 0.3 mm and increases along the edge by only 0.2 mm.

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Fig. 3 Design model of the mound with a foam concrete plate of various thicknesses

Table 2 Vertical displacements of the main site of the roadbed Section

Without plate

Plate thickness (cm) 10

20

30

Plate edge

3.5

4

4

3.7

Middle plate

6.2

6

6

5.9

The calculation of vertical stresses in the program is performed in two stages: • Stresses from its own weight are calculated; • Stresses from own weight and load are calculated. Excessive stresses (stresses caused by the load) are calculated values. The distribution of excess vertical stresses (kPa) in a horizontal plane at a depth of 40 cm from the main site of the subgrade is given in Table 3. Table 3 Vertical excess stresses (kPa) in the horizontal plane at a depth of 40 cm from the main platform of the roadbed Payment

Plate section Edge

Under the rail

The middle

Without plate

32.8

82.8

72.4

With a plate of 10 cm

33

78.6

72.4

With a plate of 20 cm

35.7

73.9

70.7

With a plate of 30 cm

39

69.4

67.4

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The analysis of Table 3 shows that the foam concrete plate has a significant stress distribution in soils. The 10-cm-thick plate has almost no effect on the level of stresses in the ground at a depth of 40 cm in cross section below the middle of the structure. In this case, the vertical stresses under the edge of the plate increase and decrease under the rail. 20 and 30 cm plates have similar, but more pronounced distribution dependence. In addition, due to the increased rigidity of the structure with an increase in its thickness, an increasing part of the load is transferred to the edges of the plate, the pressure on the middle decreases. As a percentage, the change in excess vertical stresses is shown in Table 4. In percent, the maximum stress reduction in the subgrade soil under the plate is observed in the cross section below the rail and is 16.2% with a foam concrete thickness of 30 cm. The vertical stresses in the cross section under the rail (Table 4) are of particular interest, because it is in this place, in accordance with operating experience and scientific research, that stresses above 80 kPa cause permanent deformations of the subgrade and lead to a breakdown of the path. The data of Fig. 4 reflects the reduction of excessive vertical stresses in soils in the subramp area. Stress values are somewhat overestimated for the indicated depth Table 4 Change in excess vertical stresses as a percentage of the “no-plate” calculation values Payment

Plate section Edge

With a plate of 10 cm

−0.6

Under the rail 5.1

The middle 0.0

With a plate of 20 cm

−8.8

10.7

2.3

With a plate of 30 cm

−18.9

16.2

6.9

Note “−” means an increase of stresses, “+” a decrease

Fig. 4 Vertical stresses in the section under the rail at a depth of 40 cm from the main site of the roadbed

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compared to the actual measurements, but this is explained by the fact that the ballast thickness is assumed to be 30 cm in the calculations, and the experimental stress measurements are given for the ballast standard thickness of 40–50 cm depending on the constructive solution of the upper structure. Further analysis of the excess stresses with their comparison with the allowable value made it possible to formulate the main conclusions and recommendations for the design given below. The obtained results can be used in the design of new and reconstruction of existing railways as a justification for the possibility of using the proposed geoecoprotective structure as part of the railway roadbed.

4 Conclusions The main conclusions and recommendations for the design of the railway subgrade with a foam concrete plate to ensure geoecoprotective and firming functions as well as the economy of materials (rubble, sand, and gravel) are as follows: 1. For the detoxification of heavy metal ions for the service life of the upper structure of the track between major repairs (20–25 years on average), a 10-cm-thick foam concrete plate is required. At the same time, the required thickness of crushed stone in the ballast should be provided to ensure stresses within acceptable limits. 2. From the point of view of the stress–strain state, in order to ensure stresses in soils within the limits of admissible, a plate 20 cm thick can be used. At the same time, saving of rubble can be achieved, since 30 cm ballast prism thickness is enough not to exceed the allowable stress in soils. A plate with a thickness of 20 cm in terms of its geoecoprotective function can work for two periods between repairs. 3. Ballast with a thickness of 30 cm with a 30 cm foam concrete plate or a standard thickness ballast with a 20 cm plate provides a reserve for increasing the axial load while ensuring the values of vertical stresses in soils are within acceptable limits.

References 1. Sychova A, Sychov M, Rusanova E (2017) A method of obtaining geonoiseprotective foam concrete for use on railway transport. Proc. Eng. 189:681–687 2. Sychova A, Solomahin A, Hitrov A (2017) The increase of the durability and geoprotective properties of the railway subgrade. Proc. Eng. 189:688–694 3. Svatovskaya LB (2014) Geoecological properties and methods of geo-protection in transport construction. Trans. Constr. 10:28–30 4. Svatovskaya LB, Kabanov AA, Sychov MM (2017) The improvement of foam concrete geoecoprotective properties in transport construction. IOP conference series: earth and environmental science, 1755–1315 90 012010, p 90

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5. Svatovskaya LB, Shershneva MV, Sakharova AS, Baydarashvili MM, Efimova NN, Stepanova IV (2014) Quality assessment of geoecoprotective technology solutions at railway transport facilities. Tech. Saf. Tech. 2(54):34 6. Svatovskaya LB, Sakharova AS, Baidarashvili MM, Petryaev AV, Shershneva MV, Ganchits VV (2012) New geoecoprotective technologies in the construction and reconstruction of railways/monograph. St. Petersburg, Virginia 7. Amran M, Abang YH, Ali AA, Rashid RSM, Hejazi F, Safiee NA (2016) Structural behavior of axially loaded precast foamed concrete sandwich panels. Construction and Building Materials 107:307–320 8. Yang Y, Chen B (2016) Potential use of soil in lightweight foamed concrete. KSCE J Civil Eng 20(6):2420–2427 9. Kuzielová E, Pach L, Palou M (2016) Effect of activated foaming agent on the foam concrete properties. Constr Build Mater 125:998–1004 10. Krämer C, Schauerte M, Müller T, Gebhard S, Trettin R (2017) Application of reinforced three-phase-foams in uhpc foam concrete. Constr Build Mater 131:746–757 11. Namsone E, Šahmenko G, Korjakins A (2017) Durability properties of high performance foamed concrete. Proc Eng 12 Modern Build Mater Struct Tech, 760–767 12. Wan K, Li G, Wang S, Pang C (2017) 3d full field study of drying shrinkage of foam concrete. Cement Concr Compos 82:217–226 13. Sahu SS, Gandhi ISR, Khwairakpam S (2018) State-of-the-art review on the characteristics of surfactants and foam from foam concrete perspective. J Inst Eng (India): Series A 99(2):391– 405 14. Pedro R, Tubino RMC, Anversa J, De Col D, Lermen RT, Silva RA (2017) Production of aerated foamed concrete with industrial waste from the gems and jewels sector of rio grande do sul-brazil. Appl Sci (Switzerland) 7(100):985 15. Stoyanovich GM (2002) Strength and deformability of the railway roadbed with increased vibrodynamic load in the elastoplastic stage of the work of soils: Diss. dr. Tech Sci Spec 05.22.06, 360 p. Khabarovsk: DVGUPS 16. Tao C, Dong S (2017) Effects of different fly ash proportion on the physical and mechanical performance and pore structure of foam concrete. Chem Eng Trans 62:1021–1026 17. Coppola O, Magliulo G, Di Maio E (2017) Mechanical characterization of a polyurethanecement hybrid foam in compression, tension, and shear. J Mater Civ Eng 29(2):04016211 18. Paramonov VN (1998) Calculation of the bases of buildings and structures in a physically and geometrically nonlinear formulation: diss. … Dr. Tech Sci Spec 05.23.17, 377 p. St. Petersburg, Publishing House SPSUAC 19. Paramonov VN (2012) The finite element method for solving non-linear problems of geotechnics. Series “Achievements of modern geotechnics. St. Petersburg 20. Paramonov VN (2014) Numerical modeling of geotechnical problems. St. Petersburg, Virginia 21. Paramonov VN, Sakharov II (2017) Calculations of thermal stabilization of transport embankments and their bases. In the collection: Proc. Engineering, pp 472–477

The Problems of the Railway Subgrade Construction in the Subarctic Part of the Russian Cryolithozone and the Ways of Their Solution Evgeny S. Ashpiz

Abstract The article describes the peculiarities of interaction between the railway subgrade and the perennial soils of the supporting subsoil in the subarctic part of cryolithozone. We show the reasons for the degradation of permafrost soils in the subsoil and the mechanism of subgrade deformations, according to which the main principles of subgrade design in these conditions are proposed. Keywords Subgrade · Subarctic areas of cryolithozone · Permafrost soil degradation in the subsoil · Ways of stabilization · Main principles of design

1 Introduction In Russia, the vast territories are located in the subarctic zone where there are permafrost soils. Meanwhile, taking into consideration the location of the main resources and the necessity of their development, it should be expected the intensive construction of new railways and motorways chiefly in these areas in the nearest future. A characteristic feature of the subgrade, constructed in the zone of permafrost soil distribution, is its increasing deformability caused by cryogenic processes that occur in the subsoil during thawing and continue for a long time after the construction [1–4]. In these conditions, the most common type of subgrade deformation is the embankment displacements on the thawing subsoil (Fig. 1), which occur extremely unevenly, leading to the significant gauge deterioration and demanding frequent surfacing and lifting of the track. Due to these deformations, the safety of train traffic reduces that leads to a significant increase in the number of restrictions on train speeds. In the subarctic zone with permafrost soils, JSC “Russian railways” operates the Chum—Labytnangi line built in the 1940s on the Northern Railway and the line Surgut—Korotchaevo built in the 1970s on the Sverdlovskaya Railway. E. S. Ashpiz (B) Federal State Budgetary Educational Institution of Higher Education, Russian University of Transport (MIIT), Obraztsova St., 9, Moscow 127994, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_30

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Fig. 1 Section with the embankment displacements on the Chum—Labytnangi line

Table 1 Length of the sections with deformations of the embankment settlements of JSC “The Russian railways” in the subarctic zone Railways

Length (km) Tracks

Deformation sections Total

Including intensive ones with speed restriction

Relative length of deformation sections (%)

Northern

464

40.3

15.8

8.7

Sverdlovskaya

318

13.6

6.3

4.2

Deformations of the embankment settlements in such conditions have started since the time of the construction and are continuing at the time of their operation. The length of the sections with deformations of the embankment settlements at present time is given in Table 1.

2 The Analysis of Deformation Reasons As the observations show, the main reason of deformations of the subgrade constructed on permafrost soils at the first stage after the construction is the degradation of permafrost in the subsoil, caused by the violation of natural conditions of heat exchange between the atmosphere and the soil mass, manifested in [5]: • the replacement of a peat layer or the over-moistened clay loam to the draining low-moisture soil in the seasonal thawing-freezing zone;

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• the decrease of evaporation and the increase of infiltration of the heat precipitation through the surface of the bare embankment profile in comparison with natural marshy landscapes; • the increase of solar radiation absorbing by the surfaces of the embankment profile in comparison with the natural marshy landscapes; • the decline in the surface waters runoff near the embankments, resulting in the thawing effect on the pockets filled with water and filtered through the embankment. To estimate the changes in the average annual temperature of the average annual soil temperature t ξ in the subface of the suprapermafrost layer after the subgrade construction of the roadbed, we can use the technique [6], according to which the value t ξ can be found approximately by adjusting the average annual air temperature: tξ = ta + tR + tsnow + tv + tw + tλ + tin + tcn + tcv

(1)

where t a —the average annual air temperature; t R ; t snow ; t r ; t w ; t λ ; t in ; t cp ; t cv —the temperature of the correction due to the influence of: radiation, snow cover, vegetation, surface water bodies, changes in thermal conductivity during freezing and thawing, the infiltration of precipitation, the condensation of water vapor in very coarse soils, convection in water and air vapor. As it can be seen from the constituents of the value t ξ , the embankment construction makes changes almost in all of them. Let us consider which of these corrections is the most important for the subarctic zone conditions. The peculiarity of the polar regions is that they have a tundra landscape characterized with the snowstorms which carry a lot of snow. At the same time, the construction of the subgrade dramatically changes the snow deposits on its surfaces, increasing the thickness of the cover in relation to the natural conditions in the lower part of the slope and near the embankment toe, causing a strong thawing effect on the roadbed soils. Field studies of snow depositions near the embankment in the tundra show that the thickness of snow in the linkage of the slope and the embankment shoe reaches the maximum amount and the amount of snow in natural conditions increases by several times. Such a distribution of snow cover on the cross-section of the embankment grade line leads to the degradation of permafrost under the slope bottom and in the subsoil under the embankment toe. The experimental confirmation of this permafrost degradation running after the subgrade construction was obtained by MIIT in September 2012 during the inspection of the deforming embankments of the Chum—Labytnangi line. Figure 2 shows a typical example of this process in the form of the temperature field in September 2012 under the embankment of 2.5 m high on Kilometer 22 of the Chum—Labytnangi line, which was as a result of thermal process modeling with the use of the finite-difference method in the WARM program [7]. The correctness of the modeling is confirmed by the actual determination of the depth of the permafrost upper boundary with the help of drilling (Table 2).

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Fig. 2 Temperature distribution under the embankment on Kilometer 22 of the Chum—Labytangi line in September 2012

Table 2 Comparison of actual and calculated depths of the permafrost upper boundary location under the embankment on Kilometer 22 of the Chum—Labytangi line in September 2012

Data

Location Shoulder, 2.5 m from the center of track

Field, 9.5 m from the center of track

Drilling

2.5

5.5

Modeling

3.1

6.5

Similar locations of the permafrost upper boundary under the embankments with maximum thawing under the linkage of the slope and the natural soil surface were obtained on the Qinghai-Tibet railway in China [8]. The second important condition that provokes the degradation process in the permafrost soils is the deterioration of surface water runoff near the embankments, which leads to the surface water stagnation, the thermokarst formation, and the subsoil thawing. Figure 3 depicts the typical formation of a thermokarst lake near the embankment toe over the course of time. Later on, the accumulation of water near the embankment generates not only the lowering of the upper boundary of permafrost soils but also the flooding of the defrosted and thawed soils, which lose their bearing capacity. As a result, the zone of instability is formed in the embankment foundation, as well as plastic deformations of water-bearing soils started with their squeezing aside and their bulging out of the subgrade under the influence of the embankment weight and the dynamic train load. In course of time, if the depth of thawing increases, which is defined as thermal resistance, then the thawing process slows down, and the depression of thawing and packing is fading. These cannot be said about plastic deformations, the speed of which is actually independent of the time. Besides the long-term depressions because of the permafrost degradation on the railways with low embankments, it was noticed frosty heaving followed by the

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Fig. 3 Formation of a thermokarst lake near the deforming embankment shoe on the Chum— Labytnangi line

depression under thawing, which was supplemented with plastic lateral heaves of the weak thawing layer of the subsoil. These peculiarities of the interaction between the subgrade and the permafrost subsoils, which are characteristic to the subarctic part of the cryolithozone, should be taken into account in its design.

3 Main Principles of the Subgrade Design and Their Implementation The main conclusion of the analysis of the subgrade design experience laid in the permafrost soil conditions in the twentieth century was that the violation of natural conditions of heat exchange caused by the construction was not taken into account. In the calculations, only the conditions of conductive heat transfer were considered—as a result, the subgrade was designed with the assumption of permafrost soil thawing that caused numerous deformations. Correction factors of the railway subgrade design in the conditions of vast permafrost soils were considered in the design of new railway lines in the subarctic zone (the Yagelnaya—Yamburg railway, the Obskaya—Bovanenkovo railway) at the end of the twentieth century. The design was carried out in accordance with special technical standards [9, 10], in which the design solutions to the subgrade were based on

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Fig. 4 Cross-section of a low embankment on icy soils: 1—permafrost upper boundary location before the construction, 2—permafrost upper boundary location during the operation, 3—geotextile, 4—foam plastic, 5—sandy soil of the embankment, 6—shoulder, B—width of subgrade, b—width of berm, h—height of berm

the classification of the thermal behavior control methods of the soil masses, developed by Prof. Tsernant [11]. Thus, it was proposed to use synthetic materials like geotextile and foam plastic in the structural design of the subgrade [12, 13] to ensure the application of Principle I of the construction with the preservation of soils in the frozen state during the operation (Fig. 4). These solutions were used in the projects designed by the Institute Lengiprotrans and were fully implemented during the construction of the Obskaya—Bovanenkovo railway in Yamal at the beginning of the twenty-first century. The results of geotechnical monitoring conducted by MIIT on the Obskaya— Bovanenkovo line show that the most effective solutions to the subarctic regions are the ones that reduce the thermal insulation effect of the snow cover: • the construction of embankments with more gentle slope angle of 1:3–1:4; • the arrangement of a soil berm at the embankment toe and laying of thermal insulation in the form of foam polystyrene plates and seasonal cooling units (SCU) in it in the most difficult cases. Where subsoils are subjected to the seasonal thawing, in order to protect subgrade from heaving deformations, low embankments were also provided with thermal insulation of foam polystyrene plates under the subgrade which reduces the amount of seasonal thawing. The theoretical justification shows that it is effective to lay foam polystyrene thermal insulation on the slopes in order to prevent the degradation of permafrost soils in the subsoil in the snow-covered areas [13]. This method was used on one of the experimental sections of the Amur-Yakutskaya railway and the subsequent observations in 2009–2016 confirmed its technical and economic efficiency [14]— the subsoils under the embankment remain in a frozen state.

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4 Conclusions The perennial experience of railway construction has shown that if the peculiarities of the thermal interaction of the subgrade and the icy permafrost subsoils are not taken into consideration, then it leads to serious long-term deformations. The main thawing factor causing the degradation of permafrost soils in the subarctic part of the cryolithozone is the accumulation of snow cover on the slopes and the parts of the earth’s surface associated with them. At present, positive experience has been accumulated that allows to design subgrade in these conditions. The main principles of the subgrade design are: • the basis of the design is the sufficient information about the engineeringgeological and permafrost conditions to pass the contour of line; • the design decisions are made on the basis of the forecast for changes in permafrost conditions after the construction for the term of 50 years at least; • the forecast of the temperature condition includes all the components of the heat exchange between the atmosphere and the soil mass. Especially it should be taken into account the change of the characteristics connecting with surface soil covers (moss, snow) and the conditions of surface runoff change; • under complicated engineering-geological conditions, the plan and the grade of the line are designed together with the subgrade; • the comparison of the solutions to the subgrade is carried out according to the cost of the entire life cycle of the railway; • the preference is given to Principle I of the usage of subsoils (to prevent the soil thawing during the period of operation) for the sections laid on the icy soils. It is necessary to carry out special cooling activities on the sections where the generic solutions fail to stop permafrost degradation; • a special attention in the design is paid to the reliable sewage and storm water disposal from the subgrade. At present time, the main activities for the stabilization of the subgrade in the subarctic part of the cryolithozone have been completed and tested. These activities may include the usage of seasonal cooling units (SCU) together with the lateral berms and flat slopes of the embankment, as well as heat insulation of the slopes. For all sections, it is obligatory to restore drainage together with the elimination of thermokarst. To eliminate seasonal thawing-freezing of the subsoils, where the value of heaving exceeds the norm, it should be put heat insulation in the form of foam polystyrene coat under the ballast.

References 1. Fundamentals of Geocryology, vol 5 (1999). In: Khrustalev LN, Ershov ED (eds) Permafrost Engineering, MGU, Moscow

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2. Kondratiev VG (2010) Some geocryological problems of railways and highways on permafrost of Transbaikal and Tibet. In: Proceedings of GEO2010—the 63rd Canadian geotechnical conference and 6th Canadian permafrost conference, Calgary, Alberta 3. Zhengping L (2009) Engineering geological problems and treatment measures of permafrost along Qinghai-Tibet railway. In: Proceedings of the eighth international symposium on permafrost engineering 15–17 Oct 2009, Xi an, China, pp 384–393 4. Feng W, Ma W (2006) Experimental study of the effect of awning along the Qinghai-Tibet railway. J Glaciol Geocry 28(1):108–115 5. Ashpiz ES (2016) Experience in designing the subgrade for Russian railways located permafrost regions. In: Proceedings of the Fifth conference of geocryologists of Russia. MGU named after M. V. Lomonosov, vol 1, pp 162–168. 14–17 June 6. Garagulya LS (1985) Methodology of forecast estimation of anthropogenic changes of permafrost conditions (on the example of flat territories). MGU, Moscow 7. Emelyanov NV, Pustovoit GP, Khrustalev LN, Yakovlev SV (1994) The WARM software for modeling thermal interaction of engineering structures with permafrost. Certificate No 940281; Published by RosAPO, Moscow 8. Xiaojuan Q, Gao B, Su Q (2009) Stability of slope embankment in permafrost regions. In: Proceedings of the eighth international symposium on permafrost engineering 15–17 October, 2009, Xi an, China, pp 181–186 9. Departmental construction standards DCS 200-85 (1985) Design and construction of the subgrade of the Yagelnaya—Yamburg railway (for experimental construction) 10. Departmental construction standards. DCS 203-85 (1985) Special standards and specifications for the design and construction of the railways on the Yamal Peninsula 11. Tsernant AA (1994) Ecosystem principles of engineering geomechanics in the permafrost zone. Coll. rep. international conference on open, mining, excavation and road works Russia, 19–23 April 1994, pp 198–211 12. Ashpiz ES, Vavrinuk TS (2009) Design of longitudinal cross-section of railroad line together with construction development of subgrade in permafrost regions (based on the example of railroad Lint Tommot-Yakutsk) railway. In: Proceedings of the eighth international symposium on permafrost engineering, 15–17 Oct 2009, Xi an, China, pp 384–393 13. Ashpiz ES, Khrustalev LN, Emelyanova LV, Vedernikova MA (2010) Using of synthetic thermal insulators for conservation of frozen soil conditions in the base of railway embankment. In: Proceedings of GEO2010 the 63rd Canadian geotechnical conference 6th Canadian permafrost conference, Calgary, Alberta 14. Zhang AA, Ashpiz ES, Khrustalev LN, Shesternev DM (2018) A new way for thermal stabilization of permafrost under railway embankment. Kriosfera Zemli XXII 3:67–70

Requirements for Tramway Filler Block During Construction in Cold Regions Evgenii P. Dudkin and Kirill A. Gmirya

Abstract The tram is the most promising type of public passenger transport, especially in cold regions. Lately, much attention is given to the ecological factors (noise, vibration, and environmental pollution). This is especially important to consider in the historical districts of the city. Filler blocks are used to reduce the negative impact of noise and vibration on the environment. From the technical specifications for the material of the filler blocks, the requirements are highlighted, the control of which is paramount during construction in cold regions. The variety of modern materials for elastic elements requires additional research of inserts for cyclic loading. Keywords Public passenger transport · Noise · Vibration · Filler blocks · Testing

1 Introduction Global climate change and a fast paced growth of human population require humanity to expand to new territories, including the ones located in cold climates. Modern achievements of science and technology allow humanity to adapt to nature, but there are a few problems left which require solving. One of them is the construction and operation of the transport infrastructure. This issue is important for municipal transportation. Each type of transportation has its specific technical characteristics, as well as advantages and disadvantages which impact the planning of the transportation system and a choice of picking one or the other transportation methods. Municipal passenger transportation mostly consists of buses, trams, trolleybuses, high-speed rail, subway, and commuter rail as well as alternative types such as monorail, aerial lift, and others. As the population grows and ecology suffers, there is a need to increase ecologically clean transportation, such as tramways.

E. P. Dudkin · K. A. Gmirya (B) Emperor Alexander I Petersburg Railroads State University, Moscow Avenue 9, Saint-Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_31

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The tramway is well-suited for passenger transportation in the central city districts with high traffic. It improves access of transportation in the business districts, supporting their economic development, needless to say of ecological cleanness of this type of transport. Based on the transportation capacity, the tramway is the next after underground type of transport [1]. In case of passenger traffic flow of more than 5000 passengers per hour, its operation is less expensive than for buses and trolleybuses. Besides, more high speed characteristic of the tramway comparing with the other types of surface transport is its another advantage (its traffic speed may reach up to 90 km/h). Average speed of the tram is equal to 30 km/h, while for the bus it is equal to 18 km/h and for underground −40 km/h. The largest traffic speed is realized in case of the isolated and separate tramlines [2, 5]. The tram is more economical than other methods of city transportation. It is cheaper to operate than trolley buses, and using electricity is cheaper than gas used by the buses. Also the tram can stay in service for 30 years, compared to trolleybus’ 12 years and bus’ 10 years. Tramways are planned along main and stable passenger routes. These lines are the main links that connect the city together. Tramway can be an addition to the subway, commuter rail, and city railroads, transporting passengers along radial and peripheral routes. It is the only type of ground passenger transportation that is capable of transporting people in low temperatures and bad weather conditions [3].

2 Environmental Impact of Trams Nowadays, global tendencies focus on caring for the environment. Despite all the advantages of a tram over other types of ground-based urban transport, until recently it was standing out for increased noise and vibration effects on the environment. Noise is an undesirable, unpleasant sound vibrations, randomly changing in time and having an adverse effect on human body. Noise causes a decrease in self-control, affects the nature of decisions made, reduces attention during long-term work, and leads to nervous disorders, hearing loss, and other diseases, thus becoming a social phenomenon. Sound vibrations refer to acoustic vibrations occurring in frequency range from 20 to 20,000 Hz. The noise from the tram passing through the old structures is similar to the noise of cargo transport and accounts for 80–90 dBA. At the same time, noise standard in residential buildings does not exceed 45 dBA during the night and is not higher than 55 dBA during the daytime [4]. In addition to noise, when a vehicle is moving, oscillations arise due to unbalanced power effects in the nodes and assemblies of the moving vehicle, as well as from external influences that arise from the unevenness of the road surface. For buildings

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and structures located in close proximity to tramways, vibration effects caused by the movement of trams can be a significant factor affecting both the comfort of living and the strength of building structures. Vibration during the movement of trams is transmitted through the rail track to their support and then through the soil to surrounding buildings, being both an independent source of impact, and generating re-emitted noise. Vibrations that enter residential areas as a result of round-the-clock long-term exposure may also have an adverse effect on people’s health. A vibroacceleration of 0.1 m/s2 is considered valid for human health [6]. Environmental impact, passenger comfort, as well as main economic indicators: construction costs and lost profits, track repair costs, and operating costs depend on the correct choice of track design. Therefore, the creation of modern tramway structures requires the use of such structural elements that not only increase the economic efficiency of structures, but also significantly reduce the negative impact on the environment, in particular vibration and noise during the interaction of the track and moving vehicle [7]. Studies have shown [8] that the presence of insulating profiles (bottom and side) which are used to fix the rails and eliminate noise and vibration of the rail and for damage prevention to the adjacent road surface is a prerequisite for all tramway structures within the city.

3 Requirements for tramway filler block during construction in cold regions The filler block is a vital component required in a modern construction of tramways tracks. Its quality affects reliability, track lifespan, and noise levels. The filler blocks absorb the stress on the rail from the tram and transfer it to railroad ties and the foundation. Usage of elastic components greatly reduces the amount of vibrations, which causes damage to underground communication lines, bridges, and building foundations. Achieving an optimal bending line of the rail improves a lifespan of both the rails and the road surface. It also increases the travel comfort of the tram. In addition, it reduces the noise, causing less discomfort for passengers, pedestrians, and residents of the houses along the tramway route. Application of rubber, as well as modern composite and polymer elements, increases the electro-insulating properties of the structure. It eliminates stray voltage and electro-corrosion of the underground communication lines. Undamaged roads along the tracks increase the flow capacity of the streets and reduce traffic collisions. Exterior design and the size of the profile developed for the specific solution depend on the type of the rail and the structure of the tramway route. In addition, the profile structure needs to satisfy its application in the straight section of the route and in the curved sections of all radiuses listed in the document of standards. Exposed

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side of the profile that is facing the road surface needs to be resistant to wear and tear damage. Covered side of the profile is a barrier between the rail and the road surface. Profiles are operated in cold regions in the rail’s temperature range of −40 to + 60°C. Physical and mechanical indicators are required for the material of all filler blocks (rubber, composite, polymer): • • • • • • •

Temperature range of application with preservation of the properties; Water absorption levels; Temperature limit of fragility; Specific volume resistance to electric current; Frost coefficient for elastic recovery after compression at −25 °C; Relative residual deformation; Short-term heat resistance.

PGUPS developed specifications for the material of the filler blocks [10, 11]. Technical conditions were developed on the basis of analysis and generalization of the experience of leading domestic and foreign companies, without direct testing. They regulate the following basic physicomechanical properties of the filler blocks: shore hardness, conditional tensile strength, relative elongation at break, specific volume resistance to electric current, water saturation, relative residual deformation, and short-term thermal stability. However, this approach is compatible with only one material of the filler blocks— rubber. Currently, filler blocks are made of various materials (polymeric, composite, etc.), which is not considered in the developed specifications. At the same time, experience and tests of large foreign companies: TINES (Poland), PDT profiles (Germany), Sika (Switzerland), Getzner Werkstoffe GmbH (Austria), and Prefa (Belgium) showed the practicality and feasibility of using new materials and tramway structures. In order to substantiate and prove the working capacity, as well as the possibility of using inserts made of new materials, we tested the filler blocks «Prefarails» that did not meet the existing technical conditions’ physical and mechanical indicators (relative elongation at break, residual deformation under compression, etc.) [9]. In this case, the filler blocks were not considered as a single element, but as a component of a track-free structure on a fiber-reinforced base, which is shown in Fig. 1. Initial data: • • • • • • • •

Sizes of model 1000 × 450 × 505 mm; Fiber concrete B35; Rails Ri60; Axial load 83.35 kN/axis; Vertical load application Filler blocks «Prefarails», The number of loading cycles 12 million cycles; Frequency 5 Hz.

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Fig. 1 Testing the full-scale model

The measurement results were recorded by a «Hercules» strain gauge station. The sensors used are strain gauges with a resistance of 120 and a base of 20 mm. The registration of stresses and displacements was made at 0, 3.3, 6.8, 9.9, and 12.1 million cycles. According to foreign sources, as well as GUP “Gorelektrotrans” for a period of 25 years (the service life of the rails), the average number of loading cycles is about 5 million cycles. The model was loaded with a dynamically vertical perturbing force with a frequency of 5 Hz. The value of the force is identical to the load from the tram wheel on the rail and is 4.25 ton-force. The minimum value of the force at the time of unloading is taken as 0.5 tf to avoid a blow. The test result is shown in Fig. 2. The design of the track showed its performance without significant changes in the stress–strain state and elastic characteristics with the number of cycles—12.096 million, which is more than twice the average number of cycles for the estimated service life. For the entire test period, no visual damage to the asphalt pavement and the concrete base was noted. The maximum horizontal displacements of asphalt were noted in the initial test period (the run-in period) and were 0.28 mm; after 3.37 million cycles—0.2 mm; after 6.755 million cycles 0.1 mm, after 9.94 million— 0.08 mm. The stresses in the fibrous concrete are significantly less than permissible, which confirms the performance of the filler blocks in the entire range of cyclic loads.

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Fig. 2 Movement graph for million load cycles

In the initial period, there was an increase in stresses by a factor of 2–3, due to an increase in the stiffness of the filler blocks, and then the stresses stabilize (which corresponds well with the results of measuring the displacements of the rail).

4 Conclusions The tramway is considered the most promising type of ground passenger transport given its modernization and elimination of shortcomings, particularly noise and vibration. The liners are highlighted as one of the main methods for reducing of noise and vibration. Studies have shown in order to justify the specified service life and performance of the filler blocks, it is necessary to comply with not only the basic requirements for the material of the filler blocks, but also laboratory tests for cyclic loads for all types of filler blocks.

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References 1. Samoilov DS (1983) Municipal transport. College textbook. 2nd edn, revised and mended—M. Stroyizdat, Moscow 2. Dudkin EP, Chernyaeva VA (2014) Problems of labor safety and geoecological danger of municipal transport. Tech Saf Technol Sci Int Mag 1(53):29–30 3. Oberwager G (2005) Experience in the development and operation of ballastless track. World Railw 1:47–49 4. Levadnaya NV, Chernyeva VA (2013) Rational measures and means for urban noise reducing. Transport of the Russian Federation (science, economics and practice magazine), 4(53):76–78 5. Vanhelden R (2006) New track structure. The Railr world 9:72–73 6. Hasmann H (2006) The way on the slab base. Railw World 4:14–16 7. Dudkin EP, Paraskevopulo Yu G, Sultanov NN (2012) Fiber-concrete usage in tramlines design. Trans Russ Fed (Sci Econ Prac Mag) 3–4 (40–41):77–79 8. Dudkin EP, Sultanov NN, Paraskevopulo Yu G, Paraskevopulo Yu G (2013) Urban rail transport: innovative tram track designs on a dedicated lane. Trans Russ Fed (Sci Econ Prac Mag) 4(47):51–54 9. Nguekam C, Waismann R (2005) Report No. VAK 01/04 on the Examination of the performance capability of a new elastic rail. Technische Universität Berlin, Berlin 10. TC 2539-002-03222089-2011 «Side rubber filler blocks» (technical conditions) 11. TC 2539-001-03222089-2011 «Plantar rubber filler blocks» (technical conditions)

Technogenic Hazards of Russian North Railway Isaev Vladislav , Kotov Pavel

and Sergeev Dmitrii

Abstract The degradation of permafrost can induce geohazards such as thaw subsidence affecting the performance of railway infrastructures. For example, along an 800-m-long segment Russian North Railway (from Pesets to Hanovey railway station), some zones of thaw subsidence were studied in summer 2018. The subsidence can be as high as 0.5 m. Drilling, landscape zoning, near-field transient electromagnetic sounding, and electrical resistivity tomography were carried out to assess the underlying stratigraphy and permafrost conditions. Engineering and geological conditions of the site are complicated by the presence of permafrost. Soils can be in thawed and frozen state at the base of the embankment. The spatial arrangement of thawed and frozen soils is discontinuous. The thaw settlement is due to the snow accumulation along the road embankment which insulates the ground surface in winter and prevents further ground freezing. Keywords Russian North Railway · Technogenic hazards · Hanovey

1 Introduction Spurred by recent concerns over rising transportation costs and the desire for increased accessibility for natural resource development, several cold climate railroad projects are currently under development around the globe. As demand for new cold climate railroads grows, stability of railway transportation structures over permafrost becomes an important challenge. The construction of transportation infrastructure in cold climates has always been a challenging task. The history of creation of railways in permafrost regions is already more than 110 years: Transbaikalian, Amur, Alaska, Qinghai–Tibet Railway, Gudson, Labrador, Baikal–Amur (BAM), Yamal, and some other railways in Russia, I. Vladislav · K. Pavel (B) Lomonosov Moscow State University, Moscow, Russia e-mail: [email protected] S. Dmitrii Geocryology Lab, Sergeev Institute of Environmental Geoscience RAS, Moscow, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_32

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USA, and Canada. Construction of each of these roads is an outstanding stage of transport construction and attempt to solve the main problem: to provide stability of a subgrade on sites of a permafrost and deep seasonal freezing of the soils [5]. Compared to other Arctic countries, Russia has the most developed railway infrastructure located in the permafrost area. But annual emergency repair operations on railways in the permafrost continue to be carried out. Northern transportation infrastructure is sensitive to permafrost degradation [4, 5]. Thawing of ground ice and thaw consolidation promote embankment subsidence and depressions in the road pavement [3, 8]. Permafrost warming can be amplified by construction operations (e.g., soil compaction, destruction of the vegetation cover), embankment geometry, snow accumulation on side slopes, or changes in material properties, such as the normally low albedo of pavement surfaces [3, 5, 8]. Permafrost degradation presents problems due to the high costs of construction and maintenance and because driving conditions may become hazardous. However, each territory has its own characteristics that must be considered. Therefore, a long-term study showed the significant deformations of the track that were observed along a part of Russian North Railway. This is a very difficult section where repairs often take place and embankment deformations observe. In the previous time, the intensive settlements were observed in 1953, 1959, 1966, 1968, and 1973. In 2009, a major overhaul of the track was carried out on this section using old-fashioned materials, and slight settlement was observed in 2010. In the spring of 2014, a significant increase settlement (0.5 m) was observed. After that, settlement was eliminated in 2015 and 2017. Now, the settlement tends to further development (Fig. 1). The cause of the deformations was studied in the framework of joint work between Russian and Norwegian researchers (project “Russian-Norwegian Research-based education in Cold Regions Engineering”).

Fig. 1 Thaw settlement in Hanovey site

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2 Study Site The surveyed section of the Konosha–Vorkuta line is located beyond the Arctic Circle in the extreme northeast of the Komi Republic in the Bolshezemelskaya tundra; administratively, the survey site is part of the Vorkuta region. Along the line segment from the Pesets to Hanovey railway station railway line runs along the right bank of the River Vorkuta (Fig. 2). Hanovey is located 31 km from the city of Vorkuta (67° 16 58 N, 63° 39 06 E) on the bank of the Vorkuta River. It was founded in 1948 on June 21, 1949. Population of Hanovey was 3,134 people in 1959 and only 4 people in 2011. In landscape terms, the site is characterized by the spread of peaty-bumpy tundra, which is a system of micro-depressions, hollows interspersed with hillocks and permafrost. Mosses, lichens, and ernik (dwarf birch) grow on the hillocks. Slides and hollows, along which surface runoff is periodically carried out, are overgrown with shrub of polar willow, dwarf birch, and sedge grass vegetation. A characteristic feature of the climate is a long cold winter (from October to May inclusive), followed by a short and cool summer (about 2 months—July and August). The average annual air temperature is −6 °C, the average temperature of the coldest month (January) is −20.3 °C, and the average air temperature of the warmest month (July) is +9.5 °C. The absolute minimum air temperature is −52 °C, and the absolute

Fig. 2 Location study site

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maximum air temperature is +31 °C. The average annual precipitation is 456 mm. It is distributed unevenly: 60% of the annual amount of precipitation falls in the form of rain in a short summer–autumn period. The predominant wind direction in winter is southwest; in the summer time, the northern winds dominate. The average annual wind speed is 4.1 m/s. Winter southwest winds create large snowdrifts. According to long-term data, the maximum thickness of the snow cover reaches 1.2 m in the tundra. The surveyed area is characterized by continuous evolution from the surface of Quaternary sediments, lying on Permian bedrocks. Quaternary stratum is represented by modern alluvial and moraine deposits at an open depth of up to 5 m. The cover sediments are represented by loam and silt (PrQ-iv) of yellow-brown color. They are the basement of the railway embankment throughout the surveyed area.

3 Methods and Results 3.1 A Temperatures, Permafrost Table, and Thaw Depth Ground temperatures were measured with using 6-thermistor set that was installed in 2015 in a three 6-m-depth boreholes drilled on the western side of the road. Temperatures were measured with an accuracy of 0.1 °C between −10 and 10 °C and an accuracy of 0.2 °C through the rest of the operating range (−50 to +30 °C). Data were recorded every 24 h from October 2015 to October 2018 by a HOBO U12 logger. The average annual temperature of soil in two boreholes was −0.2 … −0.5 °C, and + 0.8 °C in the third one. All temperature data were submitted in international GTN-P database [1]. Thaw depth was measured in 2016–2018 following CALM method. Measurements along embankment provided data on annual thaw patterns and identified the factors responsible for active-layer variability. Probing of the active layer is performed mechanically with a graduated metal rod. The map of the seasonal of thaw depth distribution was built after data processing (Fig. 3) Maximum depth is 1.85 m, and minimum is 0.35 m.

3.2 Geophysical Research Near-field transient electromagnetic sounding (NTES). Soundings are made by passing a current through a large, square transmitter loop. The current flow generates a steady magnetic field. Abruptly shutting off the current flow disrupts the magnetic field and induces a circulating current system in the ground below the transmitter loop. The diffusion of these induced currents is controlled by the electrical conductivity of the ground. The current attenuation is small in conductive regions, and the current

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Fig. 3 Map of the seasonal of thaw depth distribution (cm)

passes slowly through them. Resistive regions (with low conductivity), on the other hand, attenuate the current flow. Current traverses these regions more rapidly than in conductive regions. The circulating induced currents produce a secondary magnetic field that is sensed by a receiver coil located at the center of the transmitter loop. Because of the relationship of the electrical conductivity structure of the ground, the current diffusion, and the secondary magnetic field, the voltage recorded by the receiver can be used to estimate the ground conductivity. The result is that the measured voltage–time curves, or transients, can be converted into resistivity-depth functions by a nonlinear parameter estimation process called inversion [2]. The equipment used was described above. Two transmitters were used for the measurements: a battery-powered transmitter and a generator-powered transmitter for deeper exploration. Square transmitter loops were used with nominal side lengths of 50 m. Using this method allowed to determine the thickness of permafrost (Fig. 4). Frozen soils have great resistance (red zone). Thus, the thickness of permafrost in this area is 40–95 m. But the resolution of this method is small for active layer depth.

Fig. 4 Geoelectric cross section NTES

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Fig. 5 Model of electrical resistivity

Electrical resistivity tomography (ERT). Among the available near-surface geophysical methods, electrical resistivity tomography is a powerful tool for permafrost investigation because the electrical resistivity of a medium is highly sensitive to the transition from unfrozen to frozen state. An ERT was carried out along road embankment to assess the permafrost conditions. Values of apparent electrical resistivity were measured using multi-electrode installations Scala-64. The four electrodes were aligned along the survey line. The direct injection of electrical current between the two outer electrodes induced electrical potential measured between the two inner electrodes. The array with a 2-m spacing between the electrodes was first moved at 2-m interval along the survey line. The spacing was then increased to 4 m, and the array was moved again at the same interval along the survey line. A 2-dimensional data set of apparent electrical resistivity was thus obtained through the variations in depth of investigation according to the increase in array length and moving center points along the survey line. Because the road embankment was too stiff, it was not feasible to drive the electrodes into the gravel pad and carry out an ERT for the investigation of the embankment and underlying ground. The data set of apparent electrical resistivity was then inverted using the software packages to produce a model of electrical resistivity (Fig. 5). This inversion algorithm is based on the smoothness—constrained least-squares method taking into account the topography along the survey line minimized the difference between the predicted and measured values of apparent electrical resistivity by adjusting the electrical resistivity of each block making of the model. The result is an uneven distribution of thawed and frozen zones around the embankment.

3.3 Geological Structure Three boreholes and two test pit (for high and low embankments) were made to study the geological structure and properties of soils. The results are shown in Fig. 6. The underlying layers are represented by loam and silt with different ice content.

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Fig. 6 Geological structure

4 Discussion Permafrost terrain is ground that remains below 0 °C year around. The definition is based on the thermal state of the soil. Permafrost ground can be considered perennially frozen with a thin surface “active” layer that thaws each summer. The frozen ground has variable proportions of ground ice commonly well in excess of the water retained in the soil following first-time thaw. When thaw does occur, the excess water is expelled and consolidation produces substantial settlements [6, 7]. The thermal stability of the frozen ground is sensitive to minor changes in heat transfer at the ground surface. Changes in surface properties such as stripping vegetation or changes to moisture retention capacity of the soil can alter the surface heat balance, initiating thaw and increased active layer thickness. These conditions are challenging for highway engineers particularly in the southern fringe of permafrost where the ground temperature is between −1 and 0 °C. Any change in ground-air heat flux can initiate the retrogressive thaw that can result in large embankment settlements. Railroad led to a significant change in permafrost conditions at the test site (Fig. 7). It is shown on map that temperature increases at embankment. There was a thawing of permafrost and the formation of a thawed layer that does not freeze in winter. Moreover, the thick road embankment disrupts the gentle topography and acts as a barrier favoring the snow accumulation. The thawing of permafrost is therefore the snow accumulation along the embankment shoulders which insulates the ground surface in winter and prevents further ground freezing. Engineering and geological conditions of the site are complicated by the presence of permafrost. Soils can be in thawed and frozen state at the base of the embankment. The spatial arrangement of thawed and frozen soils is sporadic. Such condition is a great challenge to geocryological survey. The question is producing the correct and full description of permafrost state and permafrost dynamics. Usually, the investigators use the ground temperature and active layer depth as universal indicators of permafrost reaction to external disturbances as climate change or

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Fig. 7 Map of geocryological conditions of the Hanovey area

anthropogenic influence. For example, in our case, the average annual temperature of the soil on the sole of seasonal thawing within different landscapes is slightly different. This temperature is −0.3 to −0.5 °C and practically does not change from year to year. This is associated with significant heat expenditure on phase transitions. Thus, under these conditions, temperature monitoring becomes little informative. On the other hand, the maximum thawing depth is also not convenient as a universal indicator. Measurements of maximum thawing at the end of the warm period provide information only on the position of the permafrost table. The dynamics of this situation may depend on many factors and sometimes show the opposite dynamics. In other words, against the background of warming, this depth can be reduced. And here, the combination of research methods takes on a special significance. Thermometric observations in boreholes allow us to calibrate numerical models and also find the landscapes with no seasonal ground freezing in winter. Geophysical observations allow to outline the talik zones in the plan and in the section. Measurements of the depth of seasonal thawing allow you to select areas with shallow thawing, which often correspond to peaty ice-bounded grounds. This allows us to understand the state and dynamics of permafrost, which determines the composition and activity of hazardous processes. In particular, areas of residual thaw layer indicate the process of permafrost degradation from the top. The shallow depth of thawing and the high apparent electrical resistance of soils indicate

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the danger of the near start of the thermokarst process. The presence of a deep talik zone makes senseless the protection of permafrost from further thawing.

5 Conclusions While the road is still suitable for traffic despite the major thaw subsidence, the only economically viable mitigation of thawing of permafrost is to allow free the thaw settlement and reload the road embankment when needed until stabilization is attained. The monitoring of subsidence is recommended to assess the rate of thaw settlement. Other geophysical investigation and deep sampling would provide the clay unit thickness and undisturbed frozen samples to carry out thaw consolidation test. These data could be then integrated in a numerical simulation of the thermal regime and consolidation behavior of permafrost. The assessment of the vulnerability to thawing of permafrost is fundamental to maintain this critical access to Vorkuta. Acknowledgements This research was supported by Norwegian Center for International Cooperation in Education (“Russian-Norwegian research-based education in cold regions engineering”). Special thanks to master’s students of Lomonosov Moscow State University and Norwegian University of Science and Technology for assistance in field research. Also thanks to Scientific program #51 of the Presidium of Russian Academy of Science.

References 1. Biskaborn B, Smith SL, Noetzli J, Vieira G, Streletskiy D, Schoeneich P, Romanovsky VE, Lewkowicz AG, Abramov A, Allard M, Boike J, Christiansen HH, Delaloye R, Diekmann B, Drozdov D, Etzelmüller B, Grosse G, Guglielmin M, Ingeman-Nielsen T, Isaksen K, Ishikawa M, Johannson M, Johannsson H, Joo A, Kaverin D, Kholodov A, Konstantinov A, Kröger T, Lambiel C, Lanckman JP, Luo D, Malkova G, Matthes H, Meiklejohn I, Moskalenko N, Oliva M, Phillips M, Ramos M, Britta A, Sannel K, Sergeev D, Seybold C, Skryabin P, Wu Q, Yoshikawa K, Zheleznyak M, Lantuit H (2019) Global permafrost temperatures increased over the last decade. Nat Comm 10:264. https://doi.org/10.1038/s41467-018-08240-4 2. Fitterman DV, Labson VF (2005) Electromagnetic induction methods for environmental problems. In Butler DK (ed) Near surface geophysics—part 1. Concepts and fundamentals: Tulsa, Okla., Society of Exploration Geophysicists, pp 295–349 3. Fortier R, Bolduc M (2008) Thaw settlement of degrading permafrost: a geohazard affecting the performance of man-made infrastructures at Umiujaq in Nunavik (Québec). In: Locat J, Perret D, Turmel D, Demers D, Leroueil S (eds) Proceedings of the 4th Canadian Conference on Geohazards: from causes to management. Presse de l’Université Laval, Québec, pp 279–286 (2008) 4. Jin H, Zhao L, Wang S, Jin R (2006) Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway. Sci China, Ser D Earth Sci 49(11):1170–1183 5. Kondratiev VG (2017) Main geotechnical problems of railways and roads in kriolitozone and their solutions. Proc Eng 189:702–709 6. Kotov PI, Roman LT, Tsarapov MN (2017) The influence of thawing and consolidation conditions on the deformation properties of thawing soils. Mosc Univ Geol Bull 72(2):153–158

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7. Kotov PI, Roman LT, Sakharov II, Paramonov VN, Paramonov MB (2015) Influence of thawing conditions and type of testing on deformation characteristics of thawing soil. Soil Mech Found Eng 5(52):254–261 8. Qi JL, Sheng Y, Zhang JM, Wen Z (2007) Settlement of embankments in permafrost regions in the Qinghai-Tibet plateau. Norwegian J Geog 61:49–55

Analysis of Track Condition Based on Application of the Irregularity Length Cumulative Distribution Function Gregory A. Krug

Abstract In today’s track measuring systems, measurement results are presented as the tables, usually with 25 cm increments. Further processing and subsequent decision-making are performed pursuant to the European standards EN 13848 or to the railroads’ regulation based thereon. We and other authors have pointed out the problems of accuracy of analysis arising from the use of SD and concluded that application of SD approach produces inaccurate and non-optimal results. For a complete and undistorted description of the track condition, we have proposed using a function of the original random process that shows the value of the cumulative defect length of the corresponding size (QCDF). Our method allows to: 1. Objectively (directly, instead of indirect analysis with the SD method) assess the track technical condition based on the irregularities’ physical parameters, 2. Choose track segments for scheduling maintenance work. Unlike SD analysis, work will not be planned for segments with defects below the threshold, and segments that require work will not be overlooked. 3. Assess the quality of maintenance work performed—from the point of view of elimination of track irregularities of various sizes. 4. Predict with high accuracy track condition in future periods. For a 100 m track segment, and defect sizes exceeding 4 mm, absolute value of prediction error for a 6-month future period is less than 2.1 m with 95% probability. The advantages of applying our method: 1. Reduction of operating costs. 2. Increase in the comfort of movement. Keywords Track quality assessment · Track geometry · Irregularity size distribution function · Quasi cumulative distribution function · Track maintenance

G. A. Krug (B) Consulting Service, P.O.B. 44051, 61440 Tel-Aviv, Israel e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_33

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1 Introduction Formation of railway track maintenance strategy is based on the analysis of track geometry measurement conducted, as a rule, with track measuring car or track measuring trolleys. From the probability theory point of view, such measurement results are random variables that assume one of the possible discreet values with probability that depends on the track technical condition (random process). These results are fully and unambiguously described by the Irregularity Size Distribution Function (ISDF). One of the quantitative characteristics of this function is the Standard Deviation (SD), which allows to assess the track technical condition in a single point. Currently, SD is the quantitative characteristic of both track quality index and track maintenanceplanning threshold and is a commonly used indicator for track geometry quality description, as defined by the European Railways and EN standards. Professional publications do not provide evidence of correlation between SD values and the track technical condition [1–3]. Austrian railways [4], for example, do not rely on SD and recommend the use of modified standard deviation with σ = 1.35 m (m-mean track geometry deviation) instead of SD. [5] also provides examples showing that SD cannot be used for evaluation of track condition. We have analyzed measurement results of track geometric parameters in terms of their compliance with the normal distribution law. In our analysis, we use two independent approaches: Anderson-Darling test and method based on the calculation of the fourth central moment (Kurtosis). As a rule, measuring results of track irregularities size does not follow the normal distribution. Therefore, SD for the normal distribution formula cannot be used for SD calculations in all cases. SD for each non-normal distribution should be calculated using the formula that corresponds to its individual distribution law. Once the individual calculation has been conducted, meaningful comparison can be possible. The conventional approach to track maintenance planning is based on the analysis of SD of the measurement results of track geometric parameters. It is assumed that there is a direct and unambiguous relationship between the value of the SD and the maximum irregularities size (MIS), namely: with the increase of SD value, the size of irregularities in a particular track segment also increases. We have established with certainty that the same value of the SD can refer to the track segments with significantly different values of the defect size. Our approach allows to distinguish track segments with the same values of SD by showing the difference in the defect sizes they contain. SD criterion does not determine the shape of the ISDF, and for track sections with the same values of SD, contact stress and energy dissipated in the wheel-rail contact area could be different. Therefore, when using SD approach, track maintenance work can be erroneously scheduled for areas where correction is not required, and, conversely, not planned for areas where the irregularities’ size exceeds thresholds. As an example, Fig. 1 is based on the data extracted from the database containing measurements of the real 30–km track section. It shows a set of cumulative functions, each one of them showing the

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Fig. 1 Cumulative functions F(SD) for track segments with different MIS

combined length of 100-m segments with the MIS less than a specified number (in our example, the curves are shown for MIS values from 6 to 13 mm.) This combined length is shown as the function of SD. Let’s presume that under the SD approach, a track segment is considered in need of corrective work if SD > 2 mm. In our example, work will be scheduled for most of the segments containing 13 and 12 mm irregularities, and for 40% of 9 mm segments, and 20% of 8 mm segments, both of which do not need corrective work based on their MIS. Thus, the use of SD to assess track condition distorts the information about the track technical condition and leads to suboptimal planning.

2 Properties of QCDF Quasi Cumulative Distribution Function (QCDF) for the irregularities’ sizes is a  linear transformation of ISDF and shows the cumulative length  ∞ of the track irregularity with size equal or larger than the threshold S (Fig. 2). As can be seen from Fig. 3, track technical condition is characterized by the position of a point on a plane QCDF-Irregularity size. QCDF(S ) is characterized by the following properties:  • 0 ≤  S ≤ L—QCDF value can vary from 0 to the track segment length L,

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QCDF in m

Fig. 2 QCDF concept 10 9 8 7 6 5 4 3 2 1 0

0

1

2

3

4

5

6

7

8

9

10

11

12

Irregularity size in mm Fig. 3 QCDF for 4 track segments with the same SD (2.2–2.3) mm

 •  0 = L—for s = 0 cumulative length equal to the length of the track segment L, •   = 0—the cumulative  length for irregularity value ∞ is 0, • if s1 < s2, then  S1 <  S2, QCDF is monotonically decreasing. The values of the QCDF depend only on the values of the ISDF, but not on the distribution type. QCDF is characterized by high resolution and allows to distinguish track segments even with the same values of SD. This property is illustrated in Fig. 3, that shows the graphs for four track segments with the same SD values (SD = 2.2– 2.3 mm) with MIS from 7 up to 12 mm.

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3 Use of QCDF for Optimization of Track Maintenance The use of QCDF method significantly increases the efficiency of track maintenance works’ planning. Figure 4 is shown as an example of MIS cumulative function for several SD values. Graph allows to see the problems encountered when planning of the works is based on SD value. Graphs showed that for SD > 2 mm (n = 357) MIS is 15 mm, and 40% of the track segments have a MIS less than 11 mm. For SD parameter value within 1.4–2.4 mm range (n = 443), as prescribed by EN 13848-5, our calculation produced the value of MIS = 11 mm. However, the curve in Fig. 4 shows that for SD in this range, for 45% of the track segments MIS is less than 8 mm. So, if maintenance work is planned using the SD approach, it will be scheduled for many segments where it is unnecessary. This leads to both wasted resources and reduction of the service life of the track. For optimization of track maintenance planning, track segments with irregularities’ size above the preset S threshold should be chosen. Based on the shape of QCDF  analysis for these track segments, including the  for varying sizes of irregularities and other factors (track deterioration, subsoil position, etc.), one can make optimal decision regarding the work planning. 1.2 1 0.8

SD=(1,4-2.4)mm

0.6 0.4

SD>2MM

0.2 0 4

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MIS in mm Fig. 4 MIS cumulative function for different SD

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4 Use of the QCDF for Track Condition Monitoring In known publications, the change of track condition is described by a corresponding change of SD. QCDF makes it possible to use powerful tool for analysis of changes in track condition, including after work of tamping equipment. For that purpose, we use two parameters [6, 7]: SMIN—minimum size [mm] of an irregularity that the equipment was able to correct, µ—coefficient of efficiency, μ = (after tamping/before tamping) * 100(%) for each irregularity size. Different values of µ reflect the following situations: μ > 100-—atural increase of the length of small size irregularities (from 1 up to 3 mm), μ = 0—elimination of irregularities of large sizes (from 5 to 12 mm), 0 < μ < 100 decreasing the length of irregularities of medium size (from 2 up to 9 mm), μ ≥ 100-—increased or unchanged length of irregularities. For different track segments and working condition, SMIN can vary within a 5 mm range, which is quite significant for track condition evaluation. The results of the analysis show that there is no correlation between SD and SMIN.

5 QCDF-Based Prediction of Changes in Track Condition Prediction of track behavior is an important procedure that underlies both the frequency of track condition measurements and maintenance cost. Known published works boil down to building mathematical models of behavior of the track characteristics based on the calculation of the evaluation rate for each given track segment. All these models describe behavior of the track with some inaccuracy, the magnitude of which depends on traffic loads, track structural characteristics, environmental factors, etc. Use of this approach is very problematic because of the large number of track parameters and wide range of values. For example in [8], the author assigns track segments to 17 groups by their size evolution rate. Formula for the calculation of the evaluation rate of track deterioration [9] contains 15 different parameters. All these models use SD value or KPI as the indicator parameter, which is also quite problematic. Some publications use regression model with just a single parameter (SD or KPI) for prediction of track behavior. From a mathematical point of view, the change of the track technical condition is a random process that can be described statistically, so using deterministic models of track behavior is not valid. In this work, we use adaptive method of prediction based on analysis of relevant information about the track condition in the form of

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measurement results for the previous period in equal time intervals. Such approach allows to automatically factor in the physical characteristics of each track segment and its behavior in time. Our approach uses not just one single parameter (SD or KPI) for describing track technical condition and predicting its behavior, but set of values of  irregularity size parameters (in our case 28 points from −14 to +14 mm). Thus, it is possible to predict values  for any selected irregularity size, no matter how small. To calculate , we applied autoregressive model to the input data by minimizing (least squares method) the forward and backward errors. The accuracy of prediction is determined by the properties of input information. As a rule, high accuracy of prediction is achieved in those cases when the initial random process is stationary. In this case, stationary random process characterizes a natural change in track technical condition through normal operation. This means that the data set for all previous measurements’ results (set of samples) should belong to the same parent population. The track maintenance works significantly changes the track parameters. In this situation, the random process describing the behavior of the track becomes non-stationary, and the prediction accuracy decreases. The choice of timing parameters of prediction is based on frequency characteristics of the process. The behavior of the geometric parameters of track is characterized by a relatively high-frequency change of small size irregularities and lower frequency of irregularity size changes with time for large defects due to the influence of external factors. Therefore, the prediction of dimension changes of such irregularities for time intervals that are significantly longer than the period of natural changes makes no sense. The analysis showed that it is sufficient to use the results of the previous four measurements to obtain adequate results. We have evaluated prediction accuracy by comparing predicted and measured length for the size longitudinal level type defects from −10 up to +10 mm (absolute value of prediction error  in m) for the 6-month prediction data and for the 2month prediction data. Figure 5 shows cumulative function for the values of  for the 2-month prediction interval (340 measuring points) and 6-month prediction interval (658 measuring points). These functions are practically identical. The graphs demonstrate that the absolute value of  is below 2.1 m with 95% probability.

6 Conclusions The use of QCDF method creates fundamentally new possibilities for analyzing track technical condition on the base of the results of direct measurements and the presentation of undistorted information about the physical characteristics of irregularities, including: • Optimization of planning-it is possible to exclude the maintenance plan track segments with irregularities of obviously small size, which provides saving of resources and increases the service life of the track;

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Fig. 5 Results of 2 months and 6 months track condition prediction (longitudinal level irregularities, 100 m track segments)

• Effective monitoring of the track changes, including quality of the tamping and feedback for adjusting tamping parameters; • The unambiguous assessment of the track condition and its changes on the basis of the objective complex quality index in the form of total length of irregularities with size exceeding the threshold values for each irregularity type; • Prediction of changes of the geometric characteristics of the track with high accuracy, which facilitates effective track maintenance in the short and long term; • QCDF method can be used both as a stand-alone method and as application to SD analysis.

References 1. 2. 3. 4.

Cope GH (1993) British railway track, 6th edn. The Permanent Way Institution Esveld C (2001) Modern railway track, 2nd edn. TU-Delft Veit P (2007) Track quality-luxury or necessity? RTR Spec Maintenance Renewal 8–12 Auer F (2005) Quality analysis of track geometry maintenance optimization. ZEVrail Glasers Ann 38–45 5. Ciobanu C (2018) Use of inherent standard deviations as track design parameters. J Permanent Way Inst 136 (part 4) 6. Krug G, Madejski J (2018) Improving track condition by application of quasi cumulative distribution function. In: CETRA 2018-5 international conference on road and rail infrastructure, vol 749, pp 659–666

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7. Xu P, Liu RK, Wang F, Wang FT, Sun QX (2013) Railroad track deterioration characteristics based track measurement data mining. Math Probl Eng 2013:1–7 8. Krug G Madejski J (2015) Track maintenance strategies optimization problem, railway engineering-2015. In: 13th international conference &exhibition, Edinburgh, Scotland 9. Krug G, Madejski J (2018) Track quality assessment problems, ZEVrail 142(6–7):2–8

Study on the Effect of HDPE Stress Absorbing Layer in Preventing Reflective Cracks Zhonghua Hao, Jiankun Liu and Jian Chang

Abstract Due to the long-term effects of vehicle load and temperature, the occurrence and expansion of reflective cracks has become the most critical issue of pavement structure currently. In order to reduce the damage caused by reflective cracks on the road surface, one kind of pavement structures was adopted, in which the low-modulus HDPE modified asphalt stress absorbing layer was added between the old cement concrete pavement and the asphalt overlay. The finite element was used to establish the pavement structure model with the stress absorbing layer, and the vehicle load and temperature were applied to simulate the actual stress situation of the pavement structure. The stress analysis of the pavement structure under the effect of the two loads showed that HDPE stress absorbing layer has a better dissipative effect on the temperature stress, and the stress value of the pavement structure under the effect of vehicle loads was bigger than that under the effect of temperature, and the most reasonable thickness of HDPE stress absorbing layer to prevent reflective cracks was 2–4 cm. Keywords Reflective crack · Stress absorbing layer · Stress

1 Introduction For the prevention and treatment of reflective cracks in asphalt overlays, many developed countries began the research in the 1960s. The United States was a typical representative [1]. In 1970, the National Highways Agency (FHWA) developed the NEEP-10 program to mitigate the occurrence and expansion of reflective cracks in pavement structures. In 1988, the American Asphalt Association summarized three effective methods for slowing the generation and expansion of reflective cracks: splitting and reinforcing old cement concrete pavements without overlay structures, and Z. Hao · J. Liu (B) · J. Chang School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China e-mail: [email protected] J. Liu School of Civil Engineering, Sun Yat-sen University, Zhuhai 519082, Guangdong, China © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_34

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setting horizontal seams in the overlay of pavement structures, and adding admixture to the asphalt mixture in the overlay [2, 3]. Through the theoretical analysis of a large number of experimental roads, some foreign researchers have summarized some analytical methods for slowing reflective cracks in asphalt overlays: linear elastic theory, elastoplastic theory, and finite element method, etc. [4–6]. With the development of science and technology, especially the advancement of computer technology, the corresponding analysis software for the study of pavement structures has also been produced. Among them, the finite element analysis software is most widely used. It can analyze the stress and strain of the pavement structure by applying various loads and effects that may occur in the actual operation of the road on the simulated pavement structure, so as to obtain the corresponding data and theoretical support required for the research [7]. For the stress and strain of the pavement structure under external loads, Diyar Bozkurtf analyzed it by the finite element method [8]. Jorge B. Sousa and Jorge C. Pais proposed a finite element solid model of the pavement under vehicle load and numerically simulated the pavement structure [9]. C. L. Monismith and N. F. Coetzee solved the problem of the expansion of reflective cracks in the pavement structure under vehicle load by using the finite element method [10]. In China, Hu Changshun and Cao Dongwei conducted a finite element analysis on the pavement structure with stress absorbing layer and studied the influence of the addition of stress absorbing layer on the deflection and cracks of the pavement structure [11]. Li Shuming and Xu Zhihong used ANSYS (a kind of finite element analysis software) to numerically simulate several methods for preventing reflective cracks, and compared the differences between increasing the thickness of asphalt concrete overlay and adding the geotechnical transition layer in the pavement structure in slowing down the reflective cracks [12]. Fu Guanhua and Chen Rongsheng considered the influence of temperature on the pavement structure and studied the stress of the pavement structure, especially the asphalt overlay under the action of vehicle load and temperature [13]. For cold regions, when the atmospheric temperature is lowered, the pavement structure will shrink and deform, and the disease of reflective cracks will be particularly serious, so this paper will use ANSYS to study the effect of the asphalt pavement structure with high-density polyethylene (HDPE) on the prevention of reflective cracks in cold regions.

2 Finite Element Analysis Model 2.1 Basic Assumption Reflective cracks are generally characterized by linear elastic properties, and their viscoelastic state is only manifested when the ambient temperature is high [14]. Therefore, when the stress analysis is applied to the pavement structure, it is assumed that the finite element model of the road surface is a linear elastic body. At the same

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time, it is assumed that the contact between the structural layers of the finite element model of the entire road surface is continuous to ensure the uniform stress of the pavement structure under the external load [15]. For the constraints of the finite element model of the road surface, it is assumed that the horizontal constraint value around the subgrade is zero, and that the constraint condition of the road base is full constraint, and that the self-weight of the pavement structure is neglected in order to simplify the calculation [16].

2.2 Establishment of Finite Element Model For the finite element model of the road surface, in order to meet the actual situation of the overlay pavement structure, a three-dimensional eight-node isoparametric element is used to build the solid model, and Solid45 (a type of solid element) is selected [17]. The main calculation parameters of the finite element model of the road surface are shown in Table 1. In the process of establishing the solid model of the pavement structure, the modeling size of the subgrade is expanded to simulate the real condition of the pavement. For the original pavement structure, the construction joint of 1 cm is added in the modeling process to make reflective cracks appeared under the external load. The specific styles of the solid model are shown in Figs. 1 and 2. The solid model of the overlay pavement structure needs to be meshed for being transformed into a finite element model. Before this, in order to ensure the uniform force of the pavement structure under the external load, the Glue is used to perform the Boolean operation on the solid model, and then the solid model of the pavement structure is transformed by meshing. In the process of division, the free-division Table 1 Main calculation parameters

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1500

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24

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100

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Fig. 1 The full view of the solid model

Fig. 2 The top view of the solid model

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(SmartSize = 2) is used to segment the solid model. The specific styles of division are shown in Figs. 3 and 4.

Fig. 3 The full view of finite element model

Fig. 4 The top view of finite element model

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2.3 Vehicle Load on Pavement Structure The standard axle load (BZZ-100) is used as the vehicle load on the finite element model of the pavement structure. The force distributed on each wheel is converted into a uniform square load, and its contact area is 357.21 cm2 , and the distance between the two wheels on each side is 32 cm. The specific application pattern of vehicle load is shown in Fig. 2. For the transient dynamic analysis of the pavement structure, it is necessary to set the corresponding load steps and time steps to simulate the actual running condition of the vehicle. The road level is secondary, and the design speed is 60 km/h. According to the influence range of the vehicle on the road, set the time step to 1 s, and the eleven corresponding load steps are selected.

2.4 Temperature Load on Pavement Structure For the model under temperature load, the eight-node hexahedral solid element (Solid70) is selected, and the thermal conductivity coefficient and the linear expansion coefficient are added to the material parameters of the model. The specific values are shown in Table 2. For the analysis of the force condition of the finite element model of the pavement under temperature, the steady-state thermal of the model must be studied by the finite element method firstly, so as to know the distribution of the temperature field of the finite element model of the pavement [18]. In the analysis of steady-state thermal, the temperature sides of the pavement structure are first defined. Since the main research Table 2 Main calculation parameters Structural layer

Thickness (cm)

Asphalt concrete overlay (AC)

10

Stress absorbing layer (HDPE)

1–7

Old cement concrete pavement

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Foundation

–

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Poisson’s ratio

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Linear expansion coefficient (1/°C)

1500

0.25

1.2

2.1 × 10−5

600

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1.0

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30,000

0.15

1.5

1.0 × 10−5

100

0.35

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object is the effect of the stress absorbing layer in preventing reflective cracks, the path of the temperature sides is selected from the bottom of the old cement concrete pavement to the top of the asphalt overlay. For reflective cracks, when the temperature is lowered, the interior of the pavement structure will cool down and shrink, thereby making reflective cracks generating and expanding. When the temperature inside the pavement structure rises, the temperature has a small impact on the generation and expansion of reflective cracks and even has the effect of inhibiting the extension of reflective cracks. Therefore, when studying the effect of temperature load, this paper selects the average temperature in winter in the northeast as the temperature of the road surface for the analysis of steady-state thermal. According to statistics, the average temperature in winter in the northeast in recent years is about −10 °C, so select −10 °C as the temperature of the road surface. At the same time, it can be seen from previous studies that as the depth of the road increases, the temperature inside the pavement structure also increases [19]. Therefore, this paper chooses 0 °C as the temperature of the bottom of the old cement concrete pavement. Subsequently, the added temperature sides are solved to complete the analysis of steady-state thermal of the pavement structure.

3 Stress Analysis of Pavement Structure 3.1 Stress Analysis Under Vehicle Load Stress at the Top of Asphalt Overlay The top of the asphalt overlay is directly affected by vehicle load in the pavement structure, and the corresponding diseases in the asphalt overlay are the most serious, so the stress analysis of the top of the asphalt overlay under vehicle load is very critical. The specific analysis process is as follows: It can be concluded from Fig. 5 that under the vehicle load, the maximum tensile stress at the top of the asphalt overlay decreases from 0.51 to 0.784 MPa with the increase in thickness of HDPE stress absorbing layer from 1 to 7 cm, and the reduction is 3.39%. The equivalent stress at the top of the asphalt overlay is reduced from 0.303 to 0.265 MPa, and the reduction is 12.58%, which is a certain degree of improvement compared with the reduction of the maximum tensile stress. The maximum vertical shear stress at the top of the asphalt overlay is reduced from 0.162 to 0.126 MPa, and the reduction is 22.5%. Compared with the maximum tensile stress and equivalent stress, the maximum vertical shear stress has been greatly reduced with the increase of the thickness of the stress absorbing layer. Combined with the variation of the three kinds of stress at the top of the asphalt overlay with the thickness of stress absorbing layer, it can be known that under the vehicle load, the change of the stress at the top of the asphalt overlay is very little affected by the variation of the thickness of HDPE stress absorbing layer.

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Maximum tensile stress

Equivalent stress

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Fig. 5 Variation of stress at the top of asphalt overlay with the thickness of stress absorbing layer 0.7

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Fig. 6 Variation of stress at the bottom of asphalt overlay with the thickness of stress absorbing layer

Stress at the Bottom of Asphalt Overlay The stress absorbing layer is in direct contact with the bottom of the asphalt overlay. Under the vehicle load, the force at the bottom of the asphalt overlay is most susceptible to the stress absorbing layer, and the reflective cracks generated by the joint of the old cement concrete pavement first extend to the bottom of the asphalt overlay. Therefore, in order to study the effect of HDPE stress absorbing layer in mitigating the reflective cracks, the stress analysis at the bottom of the asphalt overlay is also very important. The specific stress analysis is as follows:

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It can be seen from Fig. 6 that as the thickness of HDPE stress absorbing layer increases from 1 to 7 cm, the maximum tensile stress at the bottom of the asphalt overlay decreases from 0.638 to 0.395 MPa, and the reduction is 38.02%, and the equivalent stress is reduced from 0.542 to 0.346 MPa correspondingly, and the reduction is 36.23%, and the maximum vertical shear stress is reduced from 0.295 to 0.171 MPa, and the reduction is 41.89%. The three kinds of stress all decrease a lot with the increase of the thickness of the stress absorbing layer, and the reduction begins to decrease gradually when the thickness of the stress absorbing layer is increased to more than 4 cm. At the same time, considering that the effect of slowing down the reflective cracks is not very good when the thickness of the stress absorbing layer is too small, it is preliminarily concluded that the optimal thickness of HDPE stress absorbing layer to slow the generation and expansion of reflective cracks is 2–4 cm.

3.2 Stress Analysis Under Temperature For the study on the stress absorbing layer, the ultimate goal is to slow the generation and extension of reflective cracks on the asphalt overlay, and compared with the stress under vehicle load in the pavement structure, the temperature stress is the secondary factor, so only analyze the temperature stress in the asphalt overlay specifically. It can be seen from Fig. 7 that under the temperature load, the maximum tensile stress in the asphalt overlay decreases from 0.799 to 0.202 MPa with the increase of the thickness of the stress absorbing layer (from 1 to 7 cm), the reduction is 74.72%, and the equivalent stress is reduced from 0.679 to 0.199 MPa, which is reduced by 70.69%, and the maximum vertical shear stress is reduced from 0.381 to 0.115 MPa, and the reduction is 69.82%. It can be seen that increasing the thickness of the stress 0.9

Maximum tensile stress

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Stress (Mpa)

0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

1

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Fig. 7 Variation of stress in the asphalt overlay with the thickness of stress absorbing layer

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absorbing layer is effective for reducing the temperature stress in the asphalt overlay. However, when the thickness of the stress absorbing layer is increased to more than 3 cm, the reduction of the three kinds of stress in the asphalt overlay is greatly reduced, and considering that the difficulty of paving will be increased if the thickness of the stress absorbing layer is too small, it is concluded that the optimal thickness of HDPE stress absorbing layer to dissipate the temperature stress is 2–3 cm. At the same time, comparing the variation of the three kinds of stress under two external loads, it can be seen that the stress value is larger under the vehicle load than that under the temperature in the asphalt layer with HDPE stress absorbing layer of the same thickness, and that the increase in thickness of the stress absorbing layer has a greater dissipative effect on the temperature stress in the asphalt overlay than on the stress under the vehicle load.

4 Conclusions The finite element method is used to compare and analyze the stress of the pavement structure with HDPE stress absorbing layer of different thicknesses under external loads, and the following conclusions are summarized: (a) Analysis of the stress in the pavement structure under the external loads shows that the reduction of the temperature stress with the increase in thickness of the stress absorbing layer is greater than that of the stress under the vehicle load, HDPE stress absorbing layer has a better dissipative effect on the temperature stress. (b) Analysis of the stress in the pavement structure under the external loads shows that the pavement structure with HDPE stress absorbing layer of the same thickness will produce a greater stress value under the vehicle load than under the temperature. (c) The analysis of the stress in the pavement structure with HDPE stress absorbing layer of different thicknesses under external loads shows that the optimum thickness of HDPE stress absorbing layer to prevent reflective cracks is 2–4 cm.

References 1. Fan Y (2013) How to promote the development of highway transportation economy. J Mod Econ Inf 15:190–201 (in Chinese) 2. Cheng Y (2006) Research on asphalt concrete overlay structure of cement concrete pavement with stress absorbing layer. Chang’an University (in Chinese) 3. Loria L, Sebaaly PE, Hajj EY (2008) Long-term performance of reflective cracking mitigation techniques in Nevada. J Transp Res Board 14(5):72–80 4. Kadar JE (1990) Performance of pavement rehabilitations under accelerated loading. In: Conference of the Australian Road Research Board, Pavements and Materials

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5. Wood WA (1984) Reducing reflection cracking in bituminous overlays. Final Summary Report, National Experimental and Evaluation Program Project No 10, Federal Highway Report No. FHWA-EP-85-02 6. Quietus HL (1979) Reflection cracking analysis for asphaltic concrete overlays. J AAPT 13(2):34–41 7. Bennert T, Maher A (2008) Field and laboratory evaluation of a reflective crack interlayer in New Jersey. J Transp Res Board 18(4):72–88 8. The 4th International RILEM Conference on Reflective Cracking in Pavement Research in Practice, Ottawa, Canada, pp 464–474 (2000) 9. Button JW, Lytton RL (2007) Guidelines for using geosynthetics with hot-mix asphalt overlays to reduce reflective cracking. J Transp Res Board 16(6):53–58 10. Baek J, Al-Qadi IL (2011) Sand mix inter layer to control reflective cracking in hot-mix asphalt overlay. Transp Res 11. Li J (2010) Study on the prevention and treatment of asphalt pavement reflection crack by rubber powder modified asphalt stress absorption layer. Beijing Jiaotong University (in Chinese) 12. Qi L (2013) Research on design method of asphalt overlay based on controlled reflection crack. Hunan University (in Chinese) 13. Zhang Z, Wu J, Di J (2003) Construction technology of STRATA reflective crack stress absorbing layer. J Wuhan Univ Technol 12(4):38–40 (in Chinese) 14. Zheng J (2003) Theory and method of anti-crack design for asphalt pavement. People’s Communications Press (in Chinese) 15. Wei J, Zhang S, Wang H, Mu Y, Zhou W (2013) Application of stress absorbing layer technology in engineering. J China Foreign Highw 6(3):63–67 (in Chinese) 16. Zeng S (2003) Research on pavement performance evaluation and analysis method. Central South University 2003 (in Chinese) 17. Tang J (2013) Theory and method of highway traffic burden analysis. Chang’an University (in Chinese) 18. Cho Y-H, Liu C, Dossey T, McCullough BF (1998) Asphalt overlay design methods for rigid pavements considering rutting, reflection cracking, and fatigue cracking. Research Report of the University of Texas 987(9):11–98 (1998) 19. Monismith CL, Coetzee NF (1980) Reflection cracking: analyses, laboratory, studies, and design considerations. AAPT 149:290–293

Railway Subgrade Stressed State Under the Impact of New-Generation Cars with 270 kN Axle Load Alexey Kolos, Andrei Romanov, Vadim Govorov and Anastasia Konon

Abstract The paper describes results of stressed state tests of railway subgrade top in under new-generation gondola cars with 270 kN axle load. Vertical stresses were measured in 2018, May and June, for test trains made up with new-generation cars, and under regular freight trains operating on the Kachkanar–Smychka section. Test stretch is situated at the eastern slope of Ural Mountains. The area has an average yearly temperature of 1.7 °C. Vertical stresses induced with rolling stock were measured with tensometer sensors (pressure cells). A 10% increase was predicted for impact applied to subgrade top with new-generation 270 kN cars on the jointed track with wooden sleepers and up to 18–20% increase on a continuous joint with concrete sleepers. Keywords Vertical stress · Subgrade · Heavy axle load

1 Introduction The strategy for the development of railway transport in the Russian Federation until 2030 provides for an increase in the freight trains weight standards, as one of the priorities in the intensive development of increasing freight traffic and efficiency of the Russian Railways network [1]. The increase in train weight is achieved either by increasing the car weight-bearing capacity, thereby rising the axial and linear load on the track or by increasing the car number in the train. Increasing car axle load is the most attractive solution to the problem. It allows increasing the traffic volume without rising the train number with minimal investment in infrastructure. At the same time, rising the train weight by increasing its length requires, in most cases, carrying out railway infrastructure reconstruction. It includes the reconstruction of stations and junctions and increasing length of receiving and departure tracks.

A. Kolos · A. Romanov · V. Govorov · A. Konon (B) Emperor Alexander I St. Petersburg State Transport University, Moskovsky pr., 9, St. Petersburg 190031, Russian Federation e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_35

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Currently, the majority (88%) of 1 million freight cars in Russia are traditional cars with an axle load of 230 kN. Their gradual replacement occurs due to the renewal of the car fleet with high-capacity cars of 250 kN axle load. In 2017, Research and Production Corporation “United Wagon Company” (RPC UWC) developed the seventh generation open-box cars with 270 kN axle load. At the Tikhvin Freight Car Building Plant, multipurpose new-generation cars were developed, certified and manufactured. The new cars were tested in 2017–2018 on the Kachkanar–Smychka section of the Sverdlovsk Railway. JSC Railway Research Institute (VNIIZhT), JSC VNIKTI, Emperor Alexander I Petersburg St. Petersburg State Transport University, Russian University of Transport (MIIT), Research Institute of Bridges and Flaw Detection and other leading institutes and testing centres took part in the tests. The aim of this study was: • to assess the actual force impact of new-generation open-box cars with 270 kN axle load on the subgrade top, • to compare obtained values to the impact of traditional open-box cars with a 230 kN axle load in comparable operating conditions. Vertical stresses were measured in 2018, May and June, for test trains made up with new-generation cars, and under regular freight trains operating on the Kachkanar– Smychka section.

2 Materials and Methods 2.1 Test Site Tests were carried out on Baranchinskaya–Laya stretch. The measurements were performed on two main tracks. On the first main track, a continuous welded track had been laid on reinforced concrete sleepers and crushed rock ballast. On the second main track, the jointed track had been laid on wooden sleepers and asbestos ballast. The speed of the new-generation and traditional rolling stock during the test period ranged from 30 to 70 km/h.

2.2 Measurement Set-up Vertical stresses induced with rolling stock were measured with tensometer sensors (pressure cells). Shielded wires were used that allow excluding the influence of external electromagnetic fields on the test results. DC power supplies with a voltage of 12 V and mobile power plants producing an alternating current of 220 V and a frequency of 50 Hz were used as power sources. To eliminate voltage fluctuations in the AC network, all measuring instruments and equipment were connected through a

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Fig. 1 Schematic diagram of stress measurement equipment

voltage stabilizer. A schematic diagram of the test equipment for stress measurement is shown in Fig. 1. Prior to the measurement start, the tensometer sensors were calibrated. As a load device, a compression testing machine with an odometer was used. A tensometric sensor was placed on a compacted sand bed at the odometer bottom. The sensor cable passed through a special cutout in a plastic ring. The sensor was covered with medium-sized sand, which was compacted after sensor installation. Next, the sensor and measuring equipment were calibrated (Fig. 2). The sensor installed in the calibration device was connected to the measuring unit (strain-gauge station). The loading was performed gradually of 15–20 kPa, with a load holding for at least 30 s. When the maximum load was reached, the sensor was unloaded with keeping each pressure level for at least 30 s. The pressure of 250 kPa was taken as a maximum load. The received data was recorded by the measuring system in the PC memory (Fig. 3).

Fig. 2 Tensometer sensors calibration

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Fig. 3 Example of strain-gauge station indications during calibration

Fig. 4 Example graph of strain-gauge station indication change on the stress

According to calibration results, graphs of strain-gauge station indication change on the stress were plotted during the loading and unloading process. An example of this graph is shown in Fig. 4. Based on the calibration results, the conversion factor was determined for the strain-gauge station indications into actual vertical stress recorded by a pressure sensor.

2.3 Tensometric Sensors Placement on Subgrade Top Considering the uneven vertical stresses distribution on the top of subgrade, during the tests vertical stresses were recorded at a depth of 45 cm under the sleepers at different sections: at the underrail section, at the sleeper end, at the track center line

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Fig. 5 Tensometric sensors placement at KP 327 + 700, Baranchinskaya–Laya stretch

and in the intervals between the sections. In this regard, sensors were installed as shown in Figs. 5 and 6. Sensors were placed at two cross-sections within the test stretch. The first section is located in the rail joint zone under the receiving sleeper. The second section is in the middle part of the panel and continuous way string.

3 Test Results Analysis Table 1 shows the values of vertical compressive stresses at subgrade top induced with locomotives, traditional gondola cars with a 230 kN axle load and new-generation cars with a 270 kN axle load. Since the trains formed from new-generation cars passed the test stretch with speed of about 40 kmph, Table 1 shows data only in the speed range of 30–40 km/h. The data in Table 1 shows for both rolling stock type, maximum vertical stress is registered at the underrail section, and minimum stress is at the track center. The mean stress value is registered at the sleeper end. The results obtained coincide well with research data, obtained in previous years by different authors [2–9]. During tests, the pattern of stress distribution at subgrade top does not differ from distributions determined in earlier studies.

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Fig. 6 Tensometric sensors placement at test stretch Table 1 Maximum vertical stress at subgrade top (45 cm below the sleeper) in the middle part of the panel Section

Maximum vertical stress at subgrade top for speed 30–40 kmph, kPa VL80 locomotive

Traditional gondola car (230 kN axle load)

New-generation gondola car (270 kN axle load)

Increase (+)/decrease (−), % for 270 kN cars comparing to 230 kN cars

I main track, continuous welded track, concrete sleepers, crushed rock ballast Under rail

63

70

87

+24.3

Sleeper end

36

46

47

+2.2

Track center

31

31

35

+12.9

II main track, jointed track, wooden sleepers, asbestos ballast Under rail

44

48

53

+10.4

Sleeper end

29

31

34

+ 9.7

Track center

17

15

20

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Vertical stresses appeared to be greater on the track with concrete sleepers and rock ballast at almost all points on subgrade top for both rolling stock types, comparing to track with wooden sleepers and asbestos ballast. This fact is also confirmed by the results of previous research. They testify convincingly to stress growth at subgrade top due to higher track stiffness. Analysis of vertical stress indicates values increase for the level of 45 cm under the sleeper for new-generation 270 kN cars compared to traditional gondola cars with 230 kN axle load. Table 1 presents the stress change, where the “+” sign reflects the stress increase, the “-” sign is for the decrease. As can be seen from Table 1, an increase in vertical stresses is observed at subgrade top. Vertical stresses remained nearly unchanged only in some cases. The maximum stresses (average between the right and left rail) increased by 10% due to axle load increase in the underrail section on the jointed track with wooden sleepers. The stress increase was 24% for new-generation cars with 270 kN axle load in the underrail section on the track with concrete sleepers. Table 2 shows the average vertical stress increase at subgrade top for newgeneration gondola cars with 270 kN axle load compared to traditional gondola cars with 230 kN axle load. Data shown in Table 2 depict that force impact growth did not exceed 20% on subgrade top comparing new-generation and traditional cars, running with 30–40 kmph speed. When bringing into service of new cars with a 270 kN axle load, it is important to predict vertical stress values at subgrade top (45 cm below the sleeper) over the entire speed range. The prediction is based on long-term research showing that with rolling stock speed increasing, vertical stresses rise linearly [5, 6]. Table 3 shows the predicted values of vertical stresses for the new-generation and traditional cars. It should be noted that the maximum vertical stresses amounted to 87 kPa and exceeded the limiting pressure of 80 kPa in the underrail section at a speed of 30– 40 km/h on continuous welded track with concrete sleepers and rock ballast (45 cm under the sleeper). Emerging of vertical stresses of more than 80 kPa subgrade top is a criterion for residual deformation initiation of the clayey subgrade. Thus, vertical stresses should be excluded that exceed the bearing capacity of clayey subgrade for sections with new-generation cars operation. The presence of clay can be a deterrent to bringing into service cars with increased carrying capacity due to significant Table 2 Average vertical stress increase at subgrade top for new-generation gondola cars with 270 kN axle load compared to traditional gondola cars with 230 kN axle load Speed, kmph

30–40

Average vertical stress increase at 45 cm below the sleeper for new-generation gondola cars with 270 kN axle load, % Jointed track with wooden sleepers and asbestos ballast, the middle part of the panel

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Table 3 Prediction of vertical stress in underrail section (45 cm below the sleeper) Speed, kmph

Prediction of vertical stress in underrail section (45 cm below the sleeper), kPa Jointed track with wooden sleepers and asbestos ballast, the middle part of a panel

Continuous welded track with concrete sleepers and rock ballast

Cars with 230 kN axle load

New-generation cars with 270 kN axle load

Cars with 230 kN axle load

30–40

48

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87

50

54

59

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93

60

57

62

79

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60

65

82

99

80

63

68

85

102

New-generation cars with 270 kN axle load

changes in clay mechanical properties during periods of seasonal freezing and thawing [9].

4 Conclusion According to test results obtained in May–July 2018, vertical stresses increase at subgrade top (45 cm under the sleeper) were identified in terms of new-generation 270 kN cars operation compared to traditional gondola cars with 230 kN axle load. On average, according to test results, it is possible to predict a 10% increase of impact applied to subgrade top with new-generation 270 kN cars on the jointed track with wooden sleepers and up to 18–20% increase on a continuous joint with concrete sleepers. When preparing track sections to bring into service of new cars with a 270 kN axle load, it is necessary to ensure the bearing capacity of clay soils. It is performed depending on the actual characteristics of the subgrade soil and protective layers, and it is confirmed by calculations or survey methods with taking measures to ensure their strength under specified operating conditions [10–15].

References 1. Order of the Government of the Russian Federation of 17.06.2008 N 877-p About the Strategy for the Development of Railway Transport in the Russian Federation until 2030 (2008) 2. Baraboshin V, Ananiev N (1978) Improving the railway track stability in the area of rail junction. Transport, Moscow 3. Berestyanyi Y (1990) The strength of high railway embankments of clay soils under the impact of trains with high axial and linear loads in the conditions of the Far Eastern Railway. PhD thesis. Leningrad

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4. Velikotnyi V (1980) Investigation of the deformability of railway subgrade clay soils under vibrational dynamic loads. PhD thesis. Leningrad 5. Konshin G (2012) Subgrade performance under train impact. Training Center on education in railway transport, Moscow 6. Prokudin I (1982) Strength and deformability of the railway subgrade made of clay soils, perceiving vibrational dynamic load. Doctoral thesis. Leningrad 7. Petriaev A (2016) The vibration impact of heavy freight train on the roadbed. Procedia Eng 143:1136–1143. https://doi.org/10.1016/j.proeng.2016.06.110 8. Kolos A, Konon A (2016) Estimation of railway ballast and subballast bearing capacity in terms of 300 kN axle load train operation. In: Zhussupbekov A (ed) Proceedings of International conference on Astana, Challenges and innovations in geotechnics, 5–7 Aug 2016. Balkema, Rotterdam 9. Petryaev A, Morozova A (2013) Railroad bed bearing strength in the period of thawing and methods of its enhancement. Sci Cold Arid Reg 5(5):548–553 10. Leng W, Mei H, Nie R, Zhao C, Liu W, Su Y (2018) Full-scale model test of heavy haul railway subgrade. J Vibr Shock 37(4) 11. Li D (2018) 25 years of heavy axle load railway subgrade research at the Facility for Accelerated Service Testing (FAST). Transp Geotech 17:51–60 12. Kalay S, LoPresti J, Davis D (2011) Development of enabling technologies for heavy axle load operations in North America. In: 9th World Congress on railway research, Lille 13. Vorster DJ, Gräbe PJ (2013) The effect of axle load on track and foundation resilient deformation under heavy haul conditions. In: Conference proceedings, 10th International Heavy Haul Association conference 2013, 4–6 February, 2013, New Delhi 14. Giner IG, Alvarez AR, Sánchez-Cambronero García-Moreno S, Camacho JL (2016) Dynamic modelling of high speed ballasted railway tracks: analysis of the behaviour. Transp Res Procedia 18:357–365 15. Mei H, Leng W, Nie R, Liu W, Chen C, Wu X (2019) Random distribution characteristics of peak dynamic stress on the subgrade surface of heavy-haul railways considering track irregularities. Soil Dyn Earthq Eng 116:205–214

Negative Impact of Geological Condition on the Roadbed Structure Natalia Kirillova, Maksim Rymin and Nadezhda Teniriadko

Abstract Various geological conditions affect the roadbed structure reinforced with geosynthetic materials. Several methods of filling embankments on weak subsoils are considered. Bedding and stress-strain behavior of soils, including the areas with cold climate, as well as its influence on the design solutions are taken into account. The calculations made enabled to determine the economic feasibility of applying various embankment structures depending on soil geology and soil properties. Keywords Embankment height · Stabilization time · Peat capacity · Piles-drains · Flexible pilework · Economic factor

1 Introduction The construction of motorways and railways is in the focus of attention in the Russian Federation. An integrated plan of modernization and main line infrastructure expansion were developed in accordance with the Decree of the President of Russia dated on May 7, 2018 №204 «About the national objectives and tasks of the development of the Russian Federation for the period up to 2024». The plan includes such federal projects (11 in total) as “Europe–Western China,” “the Northern sea route,” “Railway transport and transit,” “Communications between the centers of the economic growth,” “High-speed railway traffic.” The implementation of the integrated plan is estimated at 6.3 trillion rubles. The budget funds invested in the implementation of the infrastructure projects produce an actual multiplier impact. For example, every ruble invested in the development of the railway infrastructure is multiplied into 1.46 rubles of the country’s GDP as a result of the development of related industries (19 industries). The non-transport multiplier impact together with the development of agglomerations exceeds significantly the direct impact and amounts to 3.77 rubles per 1 ruble of the investments. N. Kirillova · M. Rymin · N. Teniriadko (B) Russian University of Transport, 9b9 Obrazcova St., Moscow 127994, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_36

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At present time, the project «The Northern latitudinal way» is dynamically being carried out. The length of a new line («Obskaya-Salekhard-Nadym») is about 2.3 thousand km, meanwhile 500 km of which is a new construction. The total amount of the investment is estimated at 235.9 bln. rubles. The planned term of the line to be put into operation is in 2023. It should be also noted that it is planned to allocate more than three dozen trillion rubles in the development of the motorway network in Russia up to 2020 and increase the density of public roads up to 10 km per 1000 people in 2030. Thus, according to the objectives, the issue of specialized, technically convenient and economically efficient transport construction in the cold regions is becoming important, and this construction should meet regulatory requirements. In general, during the road construction, one of the main factors affecting the durability and reliability is the choice of the correct technological solution of the roadbed [1]. Special attention was paid to the construction of engineering structures by scientists from different countries [2–4]. Construction in cold regions deals with operating with frozen soils both in the structure of the roadbed and in the subsoil. The variety of harsh geotechnical conditions, including weak subsoils, is aggravated in the cold regions by embankment soils and subsoils freezing [5–7]. Both soil freezing and soil thawing affect the stability of the main site of the roadbed and, finally, they affect the operational reliability of the superstructure of railway and motorway embankments [8, 9]. The paper deals with possible alternatives of both reduction of seasonal freezing impact on weak subsoils of the embankment and complete elimination of it: total replacement of the soil, partial soil replacement with piles-drains installation and flexible pilework [10, 11]. The paper concentrates on the methods of constructing a roadbed on weak subsoils considering special properties of these soils in terms of stress-strain behavior and physical properties. These features may be manifested during road construction in the areas with cold climate. To identify the most rational forms of the road structures, an economic factor has been chosen as a comparison criterion.

2 Factors Connecting with the Roadbed Structure The calculations on different variants of the embankment construction on the weak subsoils were carried out in accordance with the regulatory documents: [12–16]. On discussing the issue, the actual variant (with a slight simplification of the geological picture) of the road construction project was adopted as a reference one, in which the project involves embankment filling on weak subsoil, formed with peat and the underlying sandy soil. Alongside the route of the designed road, there were sections with the peat of various capacities in the subsoil and the embankments of different height. It was interesting to reveal how the engineering solutions could look like in these different conditions and how it would affect the cost of the implementation of this or that solution.

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Stabilization time, days

To make a comparison, the following methods were chosen as the engineering solutions of the embankment construction on weak subsoils: layer-by-layer embankment filling on weak subsoil which meets the demand for the necessary consolidation of the roadbed soils, the construction of an embankment with the use of geosynthetic materials, partial or complete peat extraction; the use of sand piles-drains and the construction of an embankment on pre-built flexible reinforced concrete pilework. It is obvious that the accepted methods of engineering measures do not cover all the methods used in practice; however, from our point of view, they are typically applied in the construction. Besides the design calculations, the following parameters were defined for the methods (where they can be applied): final settlement of the embankment due to peat compaction, final settlement of sandy soil and their total settlement and stabilization time of peat settlement. The following dimensions are accepted as the reference data: the embankment height from 4 to 9 m; the thickness of the peat layer from 4 to 12 m; peat extraction with the replacement of the peat layer of 4 m on medium-grained sand. The calculations are based on the theory of filtration consolidation. According to the developed methodology, the second type of subsoil is determined, which confirms the possibility of the stage-by-stage construction of the embankment while the soil is consolidated. The results of the calculation of final settlement value and the full time of stabilization for the embankment construction variant without any additional measures are presented in graphs in Figs. 1 and 2. The similar dependences were obtained for Hemb. = 5 m. The results shown in Fig. 2 reveal the actual correspondence of stabilization time for the analyzed heights of the embankments. The calculations for the partial or complete peat extraction methods showed that the concept of stabilization time loses its practical meaning in the case of complete peat extraction. In the case of partial peat extraction, stabilization time of the subsoil does not differ greatly from the time calculated for the subsoil of the same peat 250

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height without peat extraction. The final settlement with the use of peat extraction when the peat height remains the same is more than the final settlement without peat extraction. The technical solution with the use of piles-drains with the diameter of 0.5 m in the geosynthetic shell, made of medium-sized sand, is aimed at reducing the stabilization time of the subsoil. The final settlements of subsoil and its stabilization time for the methods, where the embankment height is from 4 to 9 m and the thickness of the peat layer is from 4 to 14 m, were calculated. The distance between the piles-drains was accepted 4, 5 and 6 m. The results of the calculation are presented in graphs in Figs. 3 and 4. The data in Fig. 3 proves the regular impact of the distance between the pilesdrains on the stabilization time of the subsoil. Meanwhile, the data in Fig. 4 shows a low dependence of the stabilization time on the embankment height. The graph in Fig. 3 allows to accept the distance between the piles-drains due to the demanded 70 60 50 40 30 20 10 0

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time of subsoil stabilization, that leads to the optimization of the cost and the rate of construction. We also consider the methods of flexible pilework implementation in order to strengthen embankment subsoils in the same engineering geological conditions. The flexible pilework has several layers of geogrid (2–3) the space between which is filled with inert materials (gravel). The flexible pilework rests on the pile capping of concrete piles. The use of pile foundation design allows to transfer the loads on rather strong sandy soil underlying peat. The calculations are done in accordance with the Code of practice for strengthened soils [17]. The calculation results are presented in graphs in Fig. 5. The calculations were made for the pile diameters of 30, 35 and 40 cm. The ratio of the pile number and the peat height for all pile types have the same character (Fig. 6). The results indicate the decrease in the pile number when the peat height increases. This phenomenon can be explained by the lower intensity of the increase of the load 350

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Fig. 6 Dependence of bearing capacity of piles on embankment height

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on the piles in Fig. 6 in comparison with the increase of bearing capacity of piles in Fig. 7. The choice of priority method should be confirmed by the economic calculations. The volume of grading, the amount of the replaced material and the filling material, the amount of sandy soil for piles-drains and the consumption of geosynthetic material were pre-determined for the economic comparison of the working methods. The increase in the amount of work and materials depends on the forecasted settlements. As an example, Figs. 8 and 9 show the nature of the rising cost of sand piles-drains, depending on the embankment height (from 4 m to 8 m) for two peat capacities (4 m and 8 m) and three distances between the drains. 350 300 250 200 150 100 50 0

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3 Conclusions In conclusion, it should be noted that the studies, the results of which are partially presented in this article, are not fully completed and, therefore, the conclusions also reflect only a part of the obtained results. Our main task was to find a quantitative (in term of costs) assessment of a particular engineering measure. The methods of embankment construction were calculated taking into account the types of geological structure of the subsoil without measures. In the same conditions, the cost of construction with partial or full replacement of weak soil, construction of sand piles-drains was estimated. The possibility of constructing the embankment with a flexible foundation was analyzed.

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The degree of stability of the embankment with the membrane of geosynthetic materials at the base is calculated, which is important to guarantee the possibility of constructing the embankment without the additional measures increasing the bearing capacity of weak subsoils, especially at the first stage of the construction. The following issue remains unresolved: the cost of “waiting time” of weak subsoil consolidation compared with the methods where there is no this “waiting time” or it can be ignored. This problem becomes relevant in the areas with cold climate where the filtration features of weak soils may differ significantly from the ones in the areas of temperate climate. The graphs presented in the paper make it possible to see the costs of constructing embankments of various heights taking into account the thickness of weak soils. The results obtained may provide guidance for further studies.

References 1. Shteyn A, Zaytsev A, Cherkasov A, Cherbakov A, Philipov S (2018) Evaluation of Options of strengthening weak bases of embankments of transport infrastructure facilities. CONFERENCE 2018, Yuzhno Sakhalinsk 2. Tsytovich NA (2013) Mechanics of frozen soils: general and applied. ISBN 978-5-397-037464. URSS, p 448 3. Wallace AJ, Williams PJ (1974) Problems of building roads in the north. Can Geogr J 89(1– 2):40–47 4. Ashpiz ES, Vavrinuk TS (2012) Computation of deformations of embankments in permafrost areas. World Trans 03:102–107 5. Zhang M, Lai Y, Dong Y (2009) Numerical study on temperature characteristics of expressway embankment with crushed-rock 192 revetment and ventilated ducts in warm permafrost regions. Cold Reg Sci Technol 59:19–24 6. Liu J-K, Peng L-Y (2009) Experimental study on the unconfined compression of a thawing soil. Cold Reg Sci Technol 58(2009):92–96 7. Zarling JP, Breley AW (1986) Thaw stabilization of roadway embankments constructed over permafrost. Report NO FHWA-AK-RD-81-20. (1986) 8. Lutskiy SY, Shepitko TV, Cherkasov AM (2013) Composite technology of earthwork construction on taliks in cryolithic zones. Sci Cold Arid Reg 5:577–581 9. Zarling JP, Breley AW (1986) Thaw stabilization of roadway embankments constructed over permafrost. Report NO FHWA-AK-RD-81-20 10. Chan QD (2009) The role of soil piles in increasing the carrying capacity of weak bases. Tran Quoc Dat. Scientific Transport and Communications Journal, Hanoi Institute of Transport and Communication, Vietnam, No. 27, pp 63–66 11. Dobrov EM, Chan QD, Le XT (2010) Soil piles—an effective method in strengthening the weak base. Vietnamese pavement and road Jour-l, Scientific and Technical Community on Bridges and Roads, Ministry of Transport, Hanoi, Vietnam, No. 7, pp 50–54 12. State Standards 25100–2011 (2011) Soils. Classification, pp 8–10 13. SP 34.13330.2012 (2012) Motorways (design) 14. SP 78. 13330.2012 (2012) Motorways (construction)

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15. Kuzahmetova EK, Kazarnovsky VD, Lvovich YM (2004) Manual for the motorway roadbed design on weak soil 16. ODM 218.2.054-2015 (2015) Recommendations for the use of textile-sand piles in the motorway construction on weak subsoils, pp 16–17 17. BS 8006-1:2010+A1:2016 (2010) Code of practice for strengthened/reinforced soils and other fills, pp 162–196

Analysis of the Experience of Operation and Scope of Application of Direct Connections to Ensure Passenger Transportation on Regional Lines Alexey Kotenko, Tatiana Malakhova

and Timofey Shchmanev

Abstract The role of transport support for all regions of the Arctic is becoming a decisive factor in their economic development, creating a powerful industrial base that ensures the economic growth of the whole country. It is the railway transport as the basis of the country’s transport system that is able to meet the needs of cold region for transportation. The development of rail transport provides a significant multiplier effect for the social-economic development of any region, especially the Arctic, and the country as a whole. The organization of transportations in direct connections allows improving the use of the capacity of the cars and improving the quality of passenger service by providing passengers with the possibility of following the route without any transfers. Developing connection system served by direct cars is one of the possible directions in solving this issue. The system of organizing transportation in direct communications should be adapted to the new principles of managing the passenger complex—customer-oriented approaches to study of the demand, development of competitive advantages of railway transport, expansion of transport accessibility for the population due to regular traffic between regions of the Russian Federation and especially with cold regions. Keywords Passenger train · Regional lines · Direct connections · Capacity of a train

A. Kotenko · T. Malakhova (B) · T. Shchmanev Emperor Alexander I St. Petersburg State Transport University, Moskovsky pr. 9, 190031 Saint Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_37

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1 Condition and Relevant Issues of Passenger Complex Improving the efficiency of passenger transportation is the most important task of “Russian Railways” OJSC, relevance thereof is stipulated in the Transport Strategy of the Russian Federation. The specialists of the passenger block are developing measures to attract additional volume of demand, in particular loyalty programs, dynamic pricing, and bonus discounts. Assigning direct cars in long-distance trains is one of the ways to improve the quality of passenger servicing. This provides ease of movement, increases utilization of rolling stock capacity, expands transport accessibility between regions of the Russian Federation [1]. Passenger traffic in 2017 amounted to almost 1.118 billion people (+7.5% by 2016), which is the highest figure in the last 8 years. Long-distance traffic is 9%, and suburban is 91% in the total traffic volume on the network. Since 2016, there has been an increase in traffic volumes in all types of connections. Thus, in the long-distance traffic, indicator “passengers dispatched” in 2015 amounted to 97.9 million passengers, in 2017—1015.7 million passengers. The growth of passenger turnover along with favorable conditions of the external environment was promoted by the use of a set of marketing tools, increase in speed, comfort and quality of transportation, development of services and effective interaction with the authorities. Improving the quality of passenger traffic is important: in 2017 the passenger train schedule was performed for 98.8%. The number of delays of trains en route was reduced by more than 3 thousand cases. Performance of the main indicators of passengers servicing, accuracy of passenger and suburban trains are the basis for success of the company and its positive image. Work in the passenger complex to promote “Russian Railways” brand is ensured in four segments: high-speed transportation, long-distance transportation, suburban traffic, matrix of the station complex products. Forming consumer’s integrated perception of the quality and reliability of any service provided by “Russian Railways” is an important task. Passenger companies have a special task: attract and satisfy a new consumer, and keep an existing one. The key factors contributing to its implementation refer to reducing travel time and expanding the geography of trains running. In order to increase competitiveness of railways in the implementation of passenger traffic, maximum compliance of the services provided with the passengers’ expectations should be achieved at all stages of the trip: from buying a ticket and boarding the train to arriving at the destination [2]. “FPC” JSC has developed a system for improving the quality of service throughout the client’s trip. At the stage “before the trip”, special attention is paid to the development of the electronic sales system, use of dynamic pricing system, introduction of RZhD-Bonus loyalty program, and increase in the sales depth to 120 days. To make the trip more comfortable, new cars equipped with modern life-support systems are purchased, uninterrupted access to the Internet is provided, level of service is increased and the range of services offered is expanded: vending machines are installed, the possibility of cashless payment for goods and services in trains

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appeared and “train shower” service is now rendered [3]. Since 2016, a fundamentally new ideology of the staff work as “a conductor for the passenger, and not for the car” is being introduced. At the stage “after the trip”, feedback is organized with passengers through various channels. Any passenger can personally contact the electronic reception office of the President of “Russian Railways” OJSC and reception office of the General Director of “FPC” JSC or fill out a questionnaire with a review of the trip online. For the convenience of transport services to the public, possibility of direct trains for the passengers between departure and destination stations is important. In the development of the passenger traffic route network, compliance with the requirements for direct carriage of the most powerful passenger traffic in terms of the volume of connections is one of the most important [4]. The presence on the network of railways of a large number of stations for the origin and redemption of flows and a significant number of correspondences with volumes insufficient for the designation of direct trains does not allow the route network to be implemented under the conditions of full direct passenger traffic development. In this regard, many passengers are forced to travel with a transfer from the train to the train at some intermediate station on the route. The need for transfer significantly reduces convenience and comfort of the trip, leading to a decrease in the speed of travel, and causes certain difficulties at the transfer point. Arranging transportation in direct cars is one of the possible ways to reduce the level of transit passenger traffic [5].

2 Development of the System of Passengers’ Transportation Organization in Yamal-Nenets Autonomous District The perspectives of development of railway infrastructure are determined by the Transport Strategy of the Russian Federation for the period up to 2030, according thereto comprehensive projects for development of railway infrastructure will be implemented to meet the needs of the country’s economy. The development of the transport system of the Arctic regions is one of the key objectives of the development of the country and its economy. The transport strategy, strategy for development of railway transport in the Russian Federation until 2030 provides for a whole range of capital-intensive measures for the development of transport infrastructure in a certain region, including railways. In the long term, development of the railway infrastructure is stipulated at the approaches to the Arctic ports of Indiga, Ust-Kara and ports of the Yamal-Kharasavey Peninsula, and Novy Port. The idea of creating Yamal Railway Company appeared at the beginning of the XXI century simultaneously with the economic growth in the country after the economic decline of 1990s. The organization of rail transportation in the Yamal-Nenets Autonomous District (YNAD), which existed before the creation of the YRC, fragmentation of the property complex, different level of transportation management at

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different sections, lack of unified economy and control system prevented the required completion of Korotchaevo–Novy Urengoy-Nadym and Novy Urengoy–Yamburg railway sections, construction thereof started as early as 1980–1985. In 1990, budget funding was suspended, and then stopped at all, what led to cessation of passenger trains movement in 1996 and jeopardized freight traffic. On April 21, 2003, at the initiative of the administration of the Yamal-Nenets Autonomous District and Ministry of Railways of the Russian Federation, a visiting board of the Ministry of Railways was held in Novy Urengoy. The Board decided to create a joint-stock company to complete unfinished construction sites and for further development of the railway infrastructure of YNAD. On August 13, 2003, “Yamal Railway Company” Open Joint-Stock Company (“YRC” OJSC) was registered. Sverdlovsk Railway, together with the Yamal-Nenets Autonomous District, strengthened the Korotchaevo–Novy Urengoy section and on September 15, 2003, passenger traffic was resumed, and “Yamal” corporate train was launched in operation. At the same time, railway station at Korotchaevo station was commissioned. From Novy Urengoy, train traffic is organized to Moscow, Novosibirsk, Chelyabinsk, Orenburg, Yekaterinburg, Kazan, Omsk, Ufa, Tyumen, Saint Petersburg, and other destinations. About 5 million passengers were dispatched for the period of “YRC” OJSC activity from 2003 to 2017. In May 2015, a new modern comfortable II class railway station was opened in Novy Urengoy. It is the largest railway station in the Yamal-Nenets Autonomous District. For the convenience of passengers, from 2017 the period of ticket sales is 90 days for long-distance trains running in domestic traffic has been set by carriers of “Russian Railways” OJSC, “FPC” JSC, “TKS” JSC, “JSC “RYA” OJSC and following trailers with direct cars of these carriers. Since May 2015, self-service transactional terminals started operation at the multifunctional railway station of Novy Urengoy station, allowing passengers arranging purchase of a travel document for long-distance passenger trains, paying with a bank card, printing a ticket previously purchased via the Internet. This work is ensured by “FPC” JSC within the framework of ongoing work to improve service, expand the list of services provided to passengers when purchasing travel documents.

3 Analysis of Performance Indicators of Railcars of the North–West Branch of “FPC” JSC in Direct Connections In the Russian Federation, passengers are transported in long-distance rail transport by a number of companies: “Federal Passenger Company” JSC, “Russian Railways” JSC, “TransClass-Service” CJSC, “Grand Service Express” TC CJSC, “Railways of Yakutia” OJSC, and companies of CIS countries. “Federal Passenger Company”

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JSC (“FPC” JSC) is the absolute leader in the market of transport services for passengers carriage in long-distance trains. “FPC” JSC has the largest passenger rolling stock in the Russian Federation—more than 20 thousand passenger cars. Trains of “FPC” JSC travel over the entire infrastructure of “Russian Railways” JSC, providing transportation services in the regions of the Russian Federation, where 98% of the population lives. “FPC” JSC daily appoints an average of about 600 trains in the passenger carriage market with a total capacity of more than 230 thousand seats. The number of passengers carried by trains of “FPC” JSC is more than 90 million passengers a year. The North-West Branch of “FPC” JSC ensures formation of 55 pairs of longdistance trains, for servicing thereof 118 trains are involved. For comparison: schedule for 2016/2017 stipulated 54 pairs that served 116 trains. In addition, trains for formation of other branches of “FPC” JSC, the Directorate of high-speed traffic and other carriers-owners of rolling stock are circulating at the Oktyabrskaya Railway test site. The current schedule takes into account both economic efficiency of transportation and the wishes of passengers. Analysis of the timetable for the movement of passenger trains on Oktyabrskaya Railway for 2017/2018 allows concluding that non-stop cars run both in domestic and international traffic. Cars of Saint Petersburg–Riga of Latvian Railways, Saint Petersburg–Kharkov, Saint Petersburg–Dnepropetrovsk, Saint Petersburg–Odessa of Ukrainian Railways, Grodno–Saint Petersburg, Soligorsk–Saint Petersburg, Gomel– Murmansk, and Brest–Murmansk of Belarusian Railways run in international traffic. Direct railcars of other branches of “FPC” JSC: Orenburg–Saint–Petersburg, Petrozavodsk–Belgorod, Murmansk–Smolensk, Arkhangelsk–Murmansk, Saint Petersburg–Cheboksary, and others are running on Oktyabrskaya Railway test site. Movement of passenger trains is organized for connection with the northern regions of the country from Saint Petersburg: year-round fast train 073/074 Saint Petersburg–Ladoga–Tyumen with direct cars of Saint Petersburg–Ladoga–Novy Urengoy, year-round fast train 077/078 Saint Petersburg–Ladoga–Vorkuta with direct cars of Saint Petersburg–Ladoga–Syktyvkar, fast year-round train 097/098 Saint Petersburg–Ladoga–Mikun (Table 1). All types of lux, sleeping compartment, communal compartment, and interregional cars are used as direct ones. The cars can run daily, on certain days of the week, in the summer period, or they can be a part of the train upon a separate request when the passenger traffic is increased. This information is indicated in the service schedule of trains [6]. Data on destination of passenger trains and direct car groups prove the classical regularities of the intra-annual cyclicality of passenger traffic but differ in dynamics. When analyzing the percentage of use of the capacity of cars, one can clearly see, firstly, the intra-annual or seasonal cyclicality with peak values of passenger traffic in the summer months, secondly, intraseasonal cyclicality with the growth of passenger traffic during holidays and pre-holiday days.

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Table 1 Tickets sales indicators in the cars of the North–West branch of “FPC” JSC Train No

Departure point

Destination point

Type of railcar

073

Tymen

Saint Petersburg

SC CC

Novy Urengoy

SC CC

Tyumen

074

Saint Petersburg

Number of seats

Sales

Capacity utilization percentage

37

1357

52.1

68

5260

68.7

16

891

56.7

48

4636

66.1

SC

39

1313

52

CC

72

5456

72.3

50

1348

50.4

077

Vorkuta

Saint Petersburg

SC CC

96

5486

54.5

078

Saint Petersburg

Vorkuta

SC

54

1724

57.2

CC

98

6242

60.9

SC

21

434

43.1

CC

23

1229

75.1

Kotlas

SC

40

1021

69.1

CC

101

5260

74.1

Syktyvkar

SC

23

600

56.7

CC

14

771

82.7

Syktyvkar 098

Saint Petersburg

4 Analysis of Functional Possibilities of Software Complexes of “Express-3” System to Plan Scope of Carriage and Diagrams of Long-Distance Train Sets With the introduction of technical means of Express-3 system on the railways, longdistance trains are considered as objects of analytical and statistical analysis. Information technology was introduced to ensure reporting of long-distance trains in operational and statistical modes [7]. Currently, there is a system of indicators characterizing the scope of work performed by the train [8]. A system of indicators is understood as such an ordered set of indicators, where every indicator gives a qualitative or quantitative characteristic of a certain side of the object under study, is interconnected with other indicators, but does not duplicate them, has the properties of reducibility and divisibility [9]. The full cycle of operation of the passenger train (from the moment of departure from the station of formation to the departure of the same station for the next trip) includes several technological operations: – initial, related to the preparation of the train set for the trip; – movement along the route in forward and reverse directions;

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– parking for embarkation–disembarkation of passengers and implementation of technical operations; – processing upon arrival and departure at the turnover station. The general requirement in the formation of the list of indicators is that assessment of operational work is complex and systematic, meets the needs of operational regulation, analysis and long-term planning of passenger traffic, and a set of indicators should ensure that full characteristics of the use of conveyances to all technological stages are obtained. As a result of the research performed, operational indicators were selected, which, by their semantic content, can be grouped into groups that characterize: – the scope of passenger traffic (correspondence of passenger traffic, the number of passengers dispatched, the scope of embarkation–disembarkation of passengers at intermediate stations, passenger turnover, average train set, and frequency of operation); – rolling stock runs (car-kilometers, train-kilometers); – use of cars in terms of time (average daily mileage and turnover of the train set); – time costs of cars (car-hours); – use of the car’s capacity (population, degree of capacity utilization, rate of seats alternation, and average distance of passenger carriage) [10]. The train of the long-distance connection, as a rule, includes several groups of cars: basic, trailed and direct. Operational characteristics are calculated and provided to the user for every group separately, and indicators of the train’s final operation include the entire set of units included in the train set design. With the help of specially developed mathematical and software in an automated mode, “Express” system calculates indicators: the number of passengers dispatched, numbers of embarkation–disembarkation, passenger turnover, average train set, time of operation of the cars, rolling stock, passenger transportation distance, number of cars, degree of utilization of the capacity of conveyances, rate of the seats alternation, turnover and average daily run of the train set [11]. The number of indicators in the process of analytical processing of information can increase on account of their differentiation or integration, depending on the analysis program, depth of study of the results of the train’s activity and aspects influencing it. Multilateral information of ACS “Express”, characterized by a complex hierarchical structure and interconnection, forms a single complex, including such indicators: – primary, obtained in the process of selling travel documents; – secondary or calculated, allowing to determine quantitative and qualitative characteristics of the object under study; – generalizing or integral, with the help thereof they determine the use of the technical potential of roads and their resources; – planned, which are additionally introduced in ACS “Express” and are used to make a comparative analysis of achieved results versus planned ones.

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The automated system for calculating the use of passenger rolling stock in the information environment of ACS “Express”, developed and implemented on the railways of Russia, has significantly improved the quality of management decisions made in the field of passenger transportation planning. It provides the operational dispatching apparatus with reliable and complete information about the operation of the train and allows effectively solving the following tasks: – – – –

determination of an economically advantageous diagram of train set; planning cycles of operation and scope of the train movement; development of tariff policy; evaluation of the competitiveness of organizational and technical measures and services offered to passengers.

The marketers of the passenger complex study the demand for destinations and determine feasibility of assigning new direct routes [12]. Train sets diagrams are developed at the level of branches of “FPC” JSC and are approved in general for “FPC” JSC on the basis of linking routes on a network scale. In the process of transportation planning, the required number of destinations of direct cars and period of their operation should be justified. The capabilities of the analytical database of ACS “Express-3” allow for a fullscale assessment of operation of direct groups of train sets. The main direction of development of the analytical capabilities of “Express” system to justify destination of direct cars is to create a mechanism ensuring search for an optimal option of transportation organization, taking into account the demand situation and potential capabilities of the passenger car fleet [13]. Achieving such a level of automation of management processes requires the development of a base, including the development of automated monitoring of indicators of competitive modes of transport and construction of software methods for forecasting passenger traffic in the long term.

5 Conclusion The role of transport support for all regions of the Arctic is becoming a decisive factor in their economic development, creating a powerful industrial base that ensures economic growth of the whole country. It is the railway transport as the basis of the country’s transport system that is able to meet the needs of a certain region for transportation. The development of rail transport provides a significant multiplier effect for the social-economic development of any region, especially the Arctic, and the country as a whole. The organization of transportations in direct connections allows improving the use of the capacity of the cars of the working fleet of “FPC” JSC and improving the quality of passenger service by providing passengers with the possibility of following the route without any transfers. Currently, there is a reduction in the number of direct routes. This is caused by a decrease in traffic volumes due to increasing competitive influence of airlines and

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vehicles. Accordingly, the issue of keeping the share of passenger traffic should be solved. Developing connection system served by direct cars is one of the possible directions in solving this issue. The system of organizing transportation in direct communications should be adapted to the new principles of managing the passenger complex-customer-oriented approaches to study of the demand, development of competitive advantages of railway transport, expansion of transport accessibility for the population due to regular traffic between regions of the Russian Federation. New technological solutions need to be developed on the basis of the use of modern information technologies that ensure calculating and monitoring the operational characteristics of all passenger trains running on the infrastructure of “Russian Railways” JSC. The automated subsystem of planning and regulation of passenger traffic (ACS-L) combines a set of information technologies that provide for collection, processing, accumulation, storage of information on passenger trips. Information technologies have been created and implemented on railway transport, ensuring solving the most important tasks of the passenger complex within the framework of ACS-L. The software complexes accompanying decision-making processes in the field of transportation planning on direct routes have been developed and put into commercial operation on the basis of ACS “Express-3”.

References 1. Strategy for the development of railway transport in the Russian Federation until 2030 (together with the Action Plan for implementation in 2008–2015 of the Strategy for the development of railway transport in the Russian Federation until 2030): [resolution] taken by the Government of the Russian Federation on June 17, 2008 No. 877-p 2. Makarova E, Ershikov N, Malakhova T (2018) Analysis of the development of the system of organization of passenger carriage in direct cars. Bull Res Results 3:49–61 3. Ivanov P (2017) Passenger is in the center of the work. Railway Transport 2:50–53 4. Krasnoshchek A (2018) Start of implementation of strategic initiatives. Railway Transport 2:4–8 5. Razumova E, Ilienko O, Ihnatiuk V (2018) Implementation of the economic and mathematical model for the development of the complex of services for passengers in the railway sector. Baltic J Econ Stud 4(2):191–197 6. Nakagawa S, Shibata M, Fukasawa N (2017) Optimization system of reserved/non-reserved seating plans for improving convenience and revenue on intercity trains. QR RTRL 58(2):105– 112 7. Canca D, De-Los-Santos A, Laporte G (2017) An adaptive neighborhood search metaheuristic for the integrated railway rapid transit network design and line planning problem. Comput Oper Res 78:1–14 8. Canca D, De-Los-Santos A, Laporte G, Mesa JA (2018) The railway network design, line planning and capacity problem: an adaptive large neighborhood search metaheuristic. Adv Concepts Methodologies Technol Transp Logistics 572:198–219 9. Cordeau JF, Toth P, Vigo D (1998) A survey of optimization models for train routing and scheduling. Transp Sci 32(4):380–404

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10. Makarova E (2014) Information technologies of ACS “Express” for processes of planning passenger carriage in direct connections. In: Intellectual Systems in Transport: Proceedings of IV International Scientific and Practical Conference “Intellect Trans-2014. PGUPS, Saint Petersburg, pp 175–180 11. Adjetey-Bahun K, Birregan B, Chatalet E, Planchet JL (2016) A model to quantify the resilience of mass railway transportation systems. Reliab Eng Syst Saf 153:1–14 12. Bussieck MR, Kreuzer P, Zimmermann UT (1998) Optimal lines for railway systems. Eur J Oper Res 96(1):321–332 13. Belenkiy M (1965) Economy of passenger rail transport, 1st edn. Transport, Moscow

Features of Tram Traffic Organization in Permafrost Areas S. A. Doronicheva , M. V. Malakhov, Evgenii P. Dudkin and G. L. Akkerman

Abstract Permafrost areas are characterized by the presence of adverse natural factors that affect production and all other areas of human activity. However, the need for mining in such areas has led to the emergence of large cities with developed social and transport infrastructure, such as Murmansk, Norilsk, and Yakutsk. The tasks of transport services to the population in such cities are traditionally assigned to public transport, and, traditionally, the issue of organizing the tram traffic in such regions is raised. The chapter analyzes the influence of climatic features of permafrost areas on the organization of tram traffic and the construction of tram tracks. The requirements for the maintenance of tram tracks in the winter period in conditions of high snowfall and high intensity of snowfall and blizzards are described. The possibility of organizing the route of the tram tracks with the optimal transverse profile of the embankment is considered: its height and provision of its aerodynamic streamlining to avoid the formation of vortex zones. Keywords Tram traffic · Tram tracks · Snowfall · Snow control · Tram operation in winter conditions

1 Introduction The development of the regions, traditionally classified as permafrost areas, connected with the necessity of mining in these regions leads to the appearance of big cities with the developed social and transport infrastructure, such as Murmansk, Norilsk, and Yakutsk. Moreover, further development of these regions will, sooner or later, raise the issue of new cities construction. Solving the problem of transport service to the people will also require considering the possible use of various kinds of S. A. Doronicheva (B) · M. V. Malakhov · E. P. Dudkin Emperor Alexander I Petersburg Railroads State University, Moscow Avenue 9, Saint-Petersburg, Russia e-mail: [email protected] G. L. Akkerman Ural State University of Railway Transport, Kolmogorova Avenue 66, Ekaterinburg, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_38

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public transport, including trams. Obviously, for this reason, it is necessary, besides the traditional parameters, to introduce a number of new ones taking into consideration unfavorable natural conditions and their impact on people’s production and other activities.

2 The Features of Snow Cover Formation in Permafrost Areas One of these unfavorable conditions is the amount of precipitation (snow) and the extents of snowstorm drift (snow transport). Let us look at the impact of these factors using the example of Norilsk. The climate is sub-arctic, extreme continental. Average annual temperature is within the interval −9.8 to −10.6 °C. The highest attainable temperature +32.5 °C was observed in July, the lowest attainable temperature −57 °C was observed in January, and for 2/3 of the year the average monthly temperatures are below zero. The specificity of the winter is low temperatures and strong high winds: in December–January—polar night, in May–June—polar day. The whole period of twilight, white and sunny nights lasts for half a year. The snow cover is observed on average for 9 months. During the winter up to 2 million tons of snow falls on the territory of the city, i.e., for each Norilsk citizen, there is on average 10 tons of snow per year. The rates of snow load and wind load are presented in Table 1. The analysis shows that the conditions differ greatly from the conditions of such a “tram” city as Saint-Petersburg. According to [1], the examined region is classified as III region of snow defense difficulty. In winter, strong winds and intense snowstorms predominate in these regions. There are regular snowdrifts often of high depth and density. The volumes of snow transport reach 250 m3 /m, in some places—400 m3 /m. The areas of high snow defense difficulty are central part of Archangelsk region, Tula, Oryol, Kursk, Voronezh, Belgorod, Lipestk, Ryazan’, Tambov, Penza regions, the republics of Mordovia, Tatarstan, Mari-El, Chuvashia, Bashkortostan, Saratov and Ulyanovsk regions, south of Nizhny Novgorod, Omsk, Kaluga and Murmansk regions, Novosibirsk and Kemerovo regions, southwestern part of Krasnoyarsk region, the republic Table 1 Characteristics of snow load and wind load for the cities of various RF regions

Federation subject

City

Snow area

Wind area

Krasnoyarsk region

Norilsk

5

3

Republic of Yakutia

Yakutsk

2

2

Saint-Petersburg

Saint-Petersburg

3

2

Murmansk region

Murmansk

5

4

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Table 2 Characteristics of snow cover by regions Name of places

Snow cover Average date of formation and destruction of stable snow cover

Average of maximum heights during winter, cm

Norilsk

30/IX-22/V

57a

Yakutsk

12/X-29/IV

37

Murmansk

10/XI-6/V

31

Saint-Petersburg

6/XII-31/III

32

a Data

in [3] are not available, taken from www.atlas-yakutia.ru/ [4]

of Altai, central part of the republic of Komi, southwestern part of Magadan region, and southern part of high arctic territory of the republic of Sakha (Yakutia) (Table 2). The largest amount of snow (about 90%) is transported in the lowest layer of the stream within 0.2 m over the snow cover. Unlike the value of snow transport in the theory of winter road maintenance, the value of snow bringing is used. Snow bringing is the amount of snow brought by snowstorms up to a road during winter. The amount of snow bringing is a part of total amount of snow bringing. Between snow transport and snow bringing, there is a relationship: Wsr − Wn sin α

(1)

where Wsr snow bringing up to a road, m3 /m; α angle between the direction of the snowstorm wind and the road. Snowdrift extent of the road (line) is determined by the form of the cross section and the height of the embankment or the depth of the cutting. To provide snowdrift resistance of the road, it is necessary to meet 2 principal requirements for the cross section: The roadbed should be aerodynamically streamlined for the wind without forming whirl zones; the wind speed over the whole surface of the road should be sufficient for blowing the snow falling on it. Wind whirl zones, occurring next to the roadbed or barriers, cause a braking effect on the movement of a surface air of the snow-wind stream and contribute to snow deposition. The characteristic of tram lines is tramways position on the same surface level as the road is or on the same surface level as the sidewalks are (for dedicated lines). That is, for tram lines the values of snow transport and snow bringing will be equal in fact, and whirl zones will be minimum owing to the lack of high embankments. The amount of snowstorm days per year is an important parameter. The data are shown in Table 3. As snowstorms we meant observing at least on type of snowstorm within 24 h. Drifting snow was not taken into consideration. The data on average duration of snowstorms for Norilsk are not available; however, based on the data for Dudinka, it is possible to accept conditionally for the winter period—100–110 h [2].

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Table 3 Amount of snowstorm days per year Month of the year

9

10

11

12

1

2

3

4

5

6

Amount of snowstorm days per month

0.4

6

9

11

11

8

8

8

5

0.4

The largest amount of snowstorm days in the period of observation

4

12

19

22

20

16

14

15

7

3

3 Additional Snow Defense Measures for Urban Tram Service The analysis of the data indicates the necessity to carry out additional snow defense activities to provide smooth tram service [10]. As snow defense activities for standalone tram lines in urban environments let us review a permanent snow defense device application designed in accordance with Road industrial methodical document ODM 218.5.001-2008 “Methodical recommendations on snow protection and snow removal of the roads” [3], in particular, fences of snow retention affect. Fences can be continuous and lattice, wooden, reinforced-concrete, or mixed. Continuous fences collect less snow than lattice ones; therefore, they are used when one-side snow retention is needed. Depending on the volume of snow brought to the road, snow retention fences are put with the height from 3 to 5 m. The height of the fence depends on the volume of snow bringing and the height of snow cover in the locality:  Hf = 0.34 Wsb + Hsc

(2)

where H f height of the fence, m; W sb volume of snow bringing, m3 /m; H sc average multi-annual maximum height of snow cover in the locality (from Table 1), m. √ Hf = 0.34 400 + 0.57 = 7.37 m The obtained value exceeds the recommended height of the fence of 3–5 m. In this case, ODM recommends putting several rows of fences with the distance between them 30H f , which is obviously unacceptable and hardly possible in the conditions of urban areas. Such types of snow protection as building high embankments and cuttings at the foot of the embankment are also of little use. Consequently, only the use of snow-cleaning and snow-removal machinery can provide a sustainable operation of tram lines in the conditions of intense snowing and snowstorm snow bringing.

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The specificities of tramway maintenance compared to roadways are that the level of snow cover higher than the rail running surface is not allowed. Moreover, in these conditions the use of tram grooved rails and standard tram switches in track construction undergoes with difficulties. Filling grooves with frozen snow and road litter may cause derailment of rolling stock and switch failures. The traditional methods of street and road network cleaning fail to provide timely snow cleaning of tramways and rails because the amount of machinery available by its parameters (including capacity) suggests cleaning road surface from snow taking into account the remaining layer. Intense snowfall and snowstorm bringing increase the requirements for cleaning speed (machinery capacity); otherwise, traffic stops are inevitable [10]. Snowstorm duration of 100 h and more requires practically 24-h work of snowremoval machinery to provide smooth tram service. For these operational conditions, it is advisable to use the track design of R-65 rails laid openly (or similar profile), with traditional assembled rails and sleepers or on continuous concrete foundation, also with railway-type switches, which results in the need of building mainly isolated tramways [7, 8]. The elevation of rails above the upper face of sleepers provides a sufficient volume of gauge space, which allows to accumulate the snow and have lead time for snow defense works organization as well as significant headways of snow-removal machines on the line. Slab pavement for the track designs of this kind should also be recognized unnecessary. This solution will make it possible to apply the switch cleaning technologies already tested in railway transport [9].

4 The Organization of Snow-Removal Machinery Operation The drawback of this decision could be the need in snow-removing works on the line. Snow cleaning, widely used in public road system as well as in railway transport, will only lead to storing snow along the track, which is not desirable, and will require additional costs for its removal, taking into account the volumes of snowing. The limits of the territory of tram lines do not allow throwing snow at a reasonable distance. There are similar limitations of cleaning snow from the carriageway of the roads running along tramways. The use of snow blowers throwing snow toward tramways should also be limited on these roads. Due to short distance of tram lines, the use of snow-cleaning trains is unprofitable; for this reason, let us consider using hybrid road-rail machinery with snow-removal attachments. The need in removing the collected snow suggests using them together with motor loading vehicles, which requires constructing tram tracks along existing roads (streets). The amount of the machinery is calculated from the needed volume of snow removal: W rmv = B L Hsc

(3)

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where B width of grasp of snow-removal attachments, m; L length of line (one-track segment), m. By setting B parameter for specialized machinery, it is necessary to take into consideration the requirements of set of rules SP98.13330.2012 [5] for the areas with the snow cover height more than 30 cm. Number of units of snow-removal machinery for cleaning one line: N=

W rmv L 1000Cspcf Vopr kc kt kavlb

(4)

where C spcf specification capacity of the machine, m3 /h; V opr operating speed of the machine, km/h; coefficient, taking into account the condition of the machine (k c = 1 for new kc machinery, and 0.6—for worn-out machinery); coefficient of working time use; kt k avlb coefficient taking into account lost working time due to lack of availability of motor snow-removal transport. The calculation of the fleet needed for cleaning tramways should consider: total amount of tramways, time loss caused by the machines running between snowcleaning working areas, time loss caused by transporting machines to/from the motor pool to the place of works, time loss caused by fueling the machinery, percentage of machines being repaired or out of order. Before substantiating the sizes of the fleet, it is advisable to plan the daily schedule of machinery and equipment circulation taking into account the tram service schedule. It is particularly important considering the data on the average duration of snowstorms and the number of snowstorm days in months.

5 Conclusions The reviewed specificities of tram operation in unfavorable climatic conditions suggest a number of provisions to be considered when organizing tram service in human settlements of permafrost areas. 1. The organization of tram service in the cities of permafrost areas is sustainable when constructing isolated tramways. The construction of street tram lines integrated with motor traffic is undesirable because of alleged filling tram rail grooves with snow and ice. The installation of short radius curves, common for tram lines of street running track, should be excluded.

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2. The recommended tram track design in these conditions is ballast track of assembled rails and sleepers with R-65 rails or laying the rails openly on continuous concrete foundation. The use of traditional groove rails is not advisable. Laying the pavement inside the track, for example, slab pavement, should also be excluded. 3. When assessing the effectiveness of tram as a type of public transport [6] for these cities, if trams are operated, it is necessary to estimate costs on snow defense organization by separating them from total operational costs. Besides assessing the resources of the city’s economy, it is also necessary to take stock of the fleet of specialized machinery from the point of view of its capabilities to work on tramways, including isolated ones. 4. Such climatic factors as the amount of precipitation (snow) and snowstorm drift extent (snow transport and snow bringing) may affect the conclusions about the effectiveness of tram as a type of public transport and help to correct the layout of future tramways in the decision-making stage. The account of these factors must be taken by the documents of the assessment of the investment appeal of tramway projects for northern areas.

References 1. Methodical recommendations on motor road greenery. Federal Road service of the Russian federation. Moscow (1998) 2. Applied scientific guide on USSR climate. Series 3 «Long-term data» , part 1–6, 21st edn. Krasnoyarsk region, Tuva ASSR, book 2, Leningrad (1990) 3. ODM 218.5.001-2008 “Methodical recommendations on snow protection and snow removal of the roads” 4. The climate guide localities in Russia. http://www.atlas-yakutia.ru/ 5. SP 98.13330.2012 Tram and trolleybus lines. Revised edition SniP (construction rules and regulations) 2.05.09-90 6. Doronicheva SA, Dudkin EP, Chernyaeva VA, Smirnov KA (2017) Tram effectiveness and competitiveness increase in the market of passenger transportation. Proceedings of Petersburg State Transport University № 2 7. Dudkin EP, Sultanov NN (2017) Justification of modern tramway designs. In: Proceedings of PGUPS, T.4, № 1, pp 24–32 8. Dudkin EP, Paraskevopulo YG, Sultanov NN, Paraskevopulo GY (2013) Urban rail transport: innovative designs of tramways on dedicated lines. Transp Russ Fed (journal of science, economy, practice) 4(47):51–54 (SPb) 9. Shal’kovski VE (2017) Snow defense organization at marshalling yards of West Siberian Directorate of infrastructure. SCIENCE TIME 6(42):108–112 10. Conger SM (2005) Winter highway operations. Transp Res Board

Analysis of Residual Deformations Accumulation Intensity Factors of the Railway Track Located in the Polar Zone Evgenii Chernyaev , Victoriia Cherniaeva , Lyudmila Blazhko and Victor Ganchits

Abstract The article gives the analysis of the results of observations for evaluation of residual deformations accumulation intensity of a railway track structure operated in severe natural climatic conditions (the observation area is located beyond the polar circle). In addition, the following were taken into account: the structure of railway track (type of intermediate fastenings, rail base, the condition of ballast layer); railway line plan; passed-through tonnage; train travelling speed and axle load. The authors of the article received the following results: in the process of changing the stress–strain performance of a railway track as a function of passed-through tonnage, there was no stage in which the value of elastic subsidence of the superstructure elements would have a constant value; taking into account the operational and stress– strain characteristics of the studied section of the railway track, the maximum tensile stresses at the edge of rail base, caused by its bending and torsion due to the vertical and transverse horizontal impact of rolling stock wheels, will not exceed 40% of the allowable values in straight sections of the track; maximum compressive stresses in the ballast under sleeper in the under-rail zone will not exceed 85% of the allowable values in straight sections of track; compressive stresses at the top of subgrade in the under-rail zone will not exceed 85% of the allowable values in straight sections of the track; the values of the modulus of elasticity of the rail base on the experimental section of railway track are in the range from 6.0 to 59.0 MPa, which indicates an insufficient rigidity of the track and, as a result, leads to an increase of elastic subsidence of the rails, weakening of the track and contributes to increase in the intensity of residual deformation accumulations and the development of defects in the structure of railway track, which is confirmed by the data of the organization operating the railway track about identifying and removal of rails from the track as a result of their defectiveness.

E. Chernyaev (B) · V. Cherniaeva · L. Blazhko · V. Ganchits Emperor Alexander I St. Petersburg State Transport University, Moscovsky Prospect 9, St. Petersburg 190031, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_39

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Keywords Railway track · Severe natural climatic conditions · Elastic deformations · Residual deformations · Modulus of elasticity of rail base · Stress–strain state of railway track

1 Introduction The intensity of accumulation of residual deformations in the structure of railway track is determined by the combination of external (operational, natural climatic) and internal (strength and stress–strain properties of separate elements of structure) factors. Natural and climatic factors, including geotechnical conditions, in some cases, have an influence exceeding operational impacts that determines the maintenance system of a railway track or its elements. The design of a railway track, including its base, should have such characteristics, at which the intensity of accumulation of residual deformations will tend to the lowest possible values that will significantly reduce operating costs and labour input for its maintenance. The article gives the analysis of the results of observations for evaluation of residual deformations accumulation intensity of a railway track structure operated in severe natural climatic conditions (the observation area is located beyond the polar circle). In addition, the following were taken into account: the structure of railway track (type of intermediate fastenings, rail base, the condition of ballast layer); railway line plan; passed-through tonnage; train travelling speed and axle load. The dependencies of the deformation and strength properties of a railway track obtained by the authors of the article, including the passed-through tonnage, correlate with the value of varying amount of labour input for maintenance, ensuring its specified performance characteristics (train speed, axle load).

2 Characteristic of Track Section Under Examination The 117 km long railway line is located in the zone of severe natural climatic conditions (average annual air temperature: –0.5 °C; frost-free period: 5 months; minimum air temperature: –44 °C; maximum temperature: +32 °C) [1]. The section of observations has a complicated plan, the total length of curves is 52% of the length of the section. The portion of curves with a radius less than 350 m is 21%, 351–500 m—22%, 501–650 m—41%. Road bed (embankment up to 3 m) for a large mileage is composed of local rocky soils, has a minimum number of deformable and unstable places [2]. Operated rolling stock: including gondola wagons with an axle load of 25 tf with carrying capacity of 108 tons, length 12.1 m, travelling speed up to 60 km/h. In 2014, the portion of trains with axle loads of 25 tf in the passed-through tonnage was 2%, in 2015—4.5%; rolling stock mileage, gross ton-kilometers, increased by 6.8%; average train gross weight in tons was increased by 2.4%; the number of travelled freight trains increased by 4.8%. The average service speed of trains decreased

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by 2%; the average axle load, taking into account the passage of trains with increased axle load, was 15.6 tons; the freight traffic density of the section for the first year of passage of trains with increased axle load increased by 2.6% and amounted to 14.35 million gross tons/year. The major repairs at the trial section were carried out along the length at different time intervals, respectively, the passed-through tonnage at the time of beginning of observations along the length of section (117 km) was in the range of 49–140 million tons.

3 Stress–strain State of Railway Track of the Trial Section Modulus of elasticity of the rail base is one of the key characteristics that determine the stress–strain state of a railway track structure as a whole [3–14]. The structure of track superstructure (rails, fasteners, ballast layer) is a multifactor, complicated design model, the resulting modulus of elasticity of which is formed by the corresponding values of its individual elements, as well as by the operation of the under-ballast layer, subgrade and its subbase [15]. With firm soil of road bed, the elastic subsidence for 70–75% is generated as a result of the stress–strain properties of the elements of track superstructure (Fig. 1). The presented dependencies were obtained as a result of processing the data set obtained by the scientific-production company “Spetsmash” during the survey of the track by the complex laboratory of engineering geological survey of the railway track road bed (LIGO), purposed to assess the technical condition of railway track by bearing capacity and deformability in the season of stable positive air temperatures [16]. Analyzing the dependencies shown in Fig. 1, it is clear that there is no stage in which the value of elastic subsidence of the elements of superstructure would have a constant value. From this, we can make the following conclusion: the structure of railway track with low operational costs will be the one that has the value of modulus of elasticity controlled by the operating organization. This is confirmed by stable operation of ballast-free structures of railway track. Considering that the air temperature in the area of the trial section has negative values during 7 months a year, which contributes to the freezing of the ballast material and the subgrade soil, this causes a change in the modulus of elasticity parameter value of rail base towards a higher value (2–4), than that in period of positive temperatures. The results of research by a number of scientists [17] established that for a track with reinforced concrete sleepers in a year-round cycle, the optimum value of modulus of elasticity of the rail base should be in the range from 100 to 504 MPa. In other cases, excessive rigidity of track increases the dynamic interactions of track and rolling stock, and lack of rigidity leads to a weakening of track and, as a consequence, increases the intensity of accumulations of residual deformations and development of defects both in the railway track structure and in the rolling stock elements. On the other hand, the rigidity of track in the vertical plane to a certain extent determines the resistance to vehicle movement. The energy dissipation power in transit with vertical vibrations decreases with the modulus of elasticity increasing [17]. Thus, the modulus of elasticity of rail base, taking into account any operational features (speed, axle

E. Chernyaev et al.

(А) MODULUS OF ELASTICITY OF RAIL BASE, MPA

384 70 60 50 40 30 20 10 0 30

50

70

90

110

130

150

130

150

(B) ELASTIC SUBSIDENCE, MM

PASSED-THROUGH TONNAGE, MILLION TONS 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 30

50

70

90

110

PASSED-THROUGH TONNAGE, MILLION TONS Fig. 1 Dependencies of changes in stress–strain performance from the tonnage passed-through on the trial section, million tons: a modulus of elasticity, MPa, b elastic subsidence of rail, mm (dashed line), elastic subsidence of sleeper, mm (solid line)

load, rolling stock characteristics, etc.), determines the intensity of accumulation of residual deformations. With the modulus of elasticity increase, the vertical force from wheel to rail increases, the deflection of rail decreases, the axle stresses at the rail bottom decrease, and the stresses in ballast increase. The dependence of stresses on the modulus of elasticity of rail base is so significant that it is necessary to conduct special instrumental surveys of track in order to determine its real value. This problem becomes especially relevant if it is necessary to evaluate the possibility of organizing traffic of cars with increased axle loads in a chosen direction. In accordance with the studies of other authors [17] for the trial section under consideration, the following conclusions can be made: • in straight sections of the track with a regular passage of rolling stock with axle load of 25 tf at a speed of 80 km/h, when the modulus of elasticity value of the rail base exceeds 90 MPa, the compressive stress in the ballast under sleeper the

60 KM/H

160

180 110

130 100

100

140

80 KM/H

100

120 90

90

90

90

80

80

90 KM/H

385 160

Analysis of Residual Deformations Accumulation Intensity …

40 KM/H

Allowable value of track modulus, MPa, with respect to non-exceedance of allowable value of compression stress under the sleeper in the rail seat area Allowable value of track modulus, MPa, with respect to non-exceedance of allowable value of compression stress on the solid subgrade in the rail seat area Allowable value of track modulus, MPa, with respect to non-exceedance of allowable value of compression stress in ballast under the sleeper in the rail seat area (rail wear - 6 mm) Allowable value of track modulus, MPa, with respect to non-exceedance of allowable value of compression stress on the solid subgrade in the rail seat area (rail wear - 6 mm)

Fig. 2 Maximum allowable values of modulus of elasticity of the rail base for regular passage of rolling stock with axle load of 30 tf

under-rail zone exceeds the allowable ones, if the value of 115 MPa is exceeded, the compressive stress at the top of subgrade in the under-rail zone will exceed the permissible values. The maximum tensile stresses in the edge of the rail bottom caused by its bending and torsion due to vertical and transverse horizontal impact of the rolling stock wheels, will occur at the minimum value of modulus of elasticity and will not exceed 40% of the allowable values; • in curved sections, in similar operational conditions, when the modulus of elasticity value of the rail base exceeds 120 MPa, the compressive stress in the ballast under a sleeper in the under-rail zone will exceed the allowable ones, when the value of 125 MPa is exceeded, the compressive stress at the top of subgrade in the under-rail zone will exceed the permissible values. The maximum tensile stresses in the edge of the rail bottom caused by its bending and torsion due to vertical and transverse horizontal impact of the rolling stock wheels, will occur at the minimum value of modulus of elasticity and will not exceed 60% of the allowable values; See Fig. 2 for maximum allowable values of modulus of elasticity of the rail base for regular passage of rolling stock with axle load of 30 tf.

4 Residual Deformations The values of modulus of elasticity of the rail base on the trial section of railway track are in the range from 6.0 to 59.0 MPa, which indicates insufficient rigidity of track and, consequently, leads to an increase of the elastic subsidence of rails, weakening of track and contributes to increase of the intensity of residual deformations accumulations and development of defects in the structure of railway track, that is

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INTENSITY OF LATERAL WEAR, MM/MLN TONS

confirmed by the findings of the work [8], the data of the organization operating the railway track about determination and withdrawal of rails from the track as a result of their defectiveness. If in 2014, in average 130 rails were used on the track, which should be replaced in a scheduled manner, then in 2015 their number reached 240 pieces. Another manifestation of the deviations of the actual rigidity of the superstructure of railway track from the regulatory value is the change in intensity of lateral wear of the rails in the curves. The results of field observations made by the scientists of the St. Petersburg State University of Railways [18, 19] confirm that in the curves of small radii the wear of rails on concrete sleepers with elastic fastenings is less than those with rigid fastening. For the trial section considered in the article, at the values of the passed-through tonnage below 50 million tons, a lower value of the coefficient of relative rigidity of the track corresponds to a higher value of the intensity of lateral wear of rails at curved sections of track, after passage of 50 million tons—a higher value of the coefficient of relative rigidity of the track corresponds to a lower value of the intensity of lateral wear of rails at curved sections of track (Figs. 3 and 4).

0.25 0.2 0.15 0.1 0.05 0

0

200

400

600

800

1000

1200

RADIUS OF CURVE, M

INTENSITY OF LATERAL WEAR, MM/MLN TONS

Fig. 3 Intensity of lateral wear accumulation, mm/million tons, depending on curve radius, m

0.25 0.2 0.15 0.1 0.05 0 49

54

59

64

69

74

79

PASSED-THROUGH TONNAGE, MLN TONS

Fig. 4 Intensity of lateral wear accumulation, mm/million tons, depending on passed-through tonnage (curve radius from 275 to 310 m)

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387

5 Conclusion 1. In the process of changing the stress–strain performance of a railway track as a function of passed-through tonnage, there is no stage in which the value of elastic subsidence of the track superstructure elements would have a constant value, while in the period of cold temperatures the modulus of elasticity parameter value of rail base changes towards a higher value (2–4), than that in period of positive temperatures. 2. Taking into account the operational and stress–strain characteristics of the railway track studied section, the maximum tensile stresses at the edge of rail bottom, caused by its bending and torsion due to the vertical and transverse horizontal impact of rolling stock wheels, will not exceed 40% of the allowable values in straight sections of the track; maximum compressive stresses in the ballast under sleeper in the under-rail zone will not exceed 85% of the allowable values in straight sections of track; compressive stresses at the top of subgrade in the under-rail zone will not exceed 85% of the allowable values in straight sections of track. 3. The values of modulus of elasticity of the rail base on the trial section of railway track are in the range from 6.0 to 59.0 MPa, which indicates insufficient rigidity of track and, consequently, leads to an increase of the elastic subsidence of rails, weakening of track and contributes to increase in the intensity of residual deformations accumulations and development of defects in the structure of railway track, that is confirmed by the data of the organization operating the railway track about determination and withdrawal of rails from the track as a result of their defectiveness. 4. At a travelling speed below 60 km/h, the growth of vertical forces affecting a track and of absolute deformations is proportional to the growth of axle load of wagon and length of train. 5. An increase of the period of elastic deformations relaxation had been recorded in the period of thawing of the base at high water level, that is important to take into account during estimation of intervals between trains [20]. 6. Operation of wagons with increased axle load 25 tf will lead to a significant reduction of time between overhauls and increase of operating expenses for maintenance of tracks and, in our opinion, can be justified at the sections (closedloop routes) upon exhaustion of throughput capacity of a line (during freight carriage by wagons with Po = 21.0 and 23.0 tf).

References 1. SP 131.13330.2012 Construction Climatology. Updated edition of SNiP 23-01-99* 2. Berzin A (2015) Heavyweights in the Light of Experiment. Gudok, p 1

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3. Akashov AN (2010) Structural-technological and organizational solutions to improve the stability of the rail track geometry at the sections of the circulation of increased weight and length trains. Thesis for the degree of Candidate of Engineering. State Educational Institution of Higher Professional Education “Moscow State University of Railway Engineering”, Moscow 4. Nusulbekov SI (2008) Effect of rail fastening rigidity on the performance of gaskets. Science News of Kazakhstan, pp 94–100 5. Zhai WM, Cai CB (2003) Train/track/bridge dynamic interactions: simulation and applications. Veh Syst Dyn 37(Supplement):653–665 6. Zagyapan M, Fairfield CA (2002) Continuous surface wave and impact methods of measuring the stiffness and density of railway ballast. NDT and E Int 35(2):75–81 7. Augustin S, Gudehus G, Huber G, Schünemann A (2003) Numerical model and laboratory tests on settlement of ballast track. In: Popp K, Schiehlen W (eds) System dynamics and long-term behaviour of railway vehicles, track and subgrade. Springer Verlag, Berlin, pp 317–336. ISBN 3-540-43892-0 8. Berggren E, Jahlénius Å, Bengtsson B-E (2002) Continuous track stiffness measurements, a new method developed by Banverket. Report No BB 02:09, 2002-09-02, Banverket. Swedish National Rail Administration, Borlänge, Sweden 9. Dahlberg T (2002a) Linear and non-linear track models for simulation of track responses. Report LiTH-IKP-R-1228, Solid Mechanics, IKP, Linköping university, Linköping, Sweden 10. Dahlberg T (2002b): Dynamic interaction between train and non-linear railway track model. In: Grundmann H, Schuëller GI (eds) Proceedings of the 4th international conference on structural dynamics, EURODYN2002, Munich, Germany, 2–5 Sept 2002. Swetz & Zeitlinger, Lisse. ISBN 90 5809 510X 11. Fryba L (1999) Vibration of solids and structures under moving loads, 3rd edn. Thomas Telford, London. ISBN 0-7277-2741-9 12. Indraratna B, Salim W, Iunescu D, Christie D (2001) Stress-strain and degradation of railway ballast under static and dynamic loading, based on large-scale triaxial testing. In: Proceedings, 15th international conference on soil mechanics and geotechnical engineering, vols 1–3. A A Balkema, Rotterdam, pp 2093–2096 13. Hyslip JP (2002) Fractal analysis of track geometry data. Transp Res Record (1785):50–57 14. Zhai WM, Cai CB, Wang QC, Lu ZW, Wu XS (2001) Dynamic effects of vehicles on tracks in the case of raising train speeds. In: Proceedings of the Institution of Mechanical Engineers, Part F, Journal of Rail and Rapid Transit, vol 215 (F12, 125–135) 15. Ashpiz ES (2012) Justification of the deformability standards for the rail base and under-sleeper base. World Transp 112–119 16. Instructions for assessing the deformability of rail base under loading train, approved by order of Russian Railways JSC No. 1648 r (2012) 17. Privalov SV (2004) Influence of rigidity of the rail base on the vehicle and track interaction. Thesis for the degree of Candidate of Engineering. All-Russian Research Institute of Railway Transport, Moscow 18. Blazhko LS (1986) Intensity of residual deformations accumulation under influence of wagons with axle load of 250 kN. Thesis for the degree of Candidate of Engineering. Leningrad Institute of Railway Transport Engineers of Order of Lenin and Order of the October Revolution named after Academician V.N. Obraztsov, Leningrad 19. Blazhko LS (2003) Technical and process assessment of strengthening of track structure on the sections of rolling stock with axle loads up to 300 kN circulation. Thesis for the academic degree of Doctor of Engineering. State Educational Institution of Higher Professional Education “St. Petersburg State University of railways”, St. Petersburg 20. Tretyakov VV (2008) Influence of the characteristics of under-ballast base on the intensity of track deteriorations accumulation in the vertical plane. Thesis for the degree of Candidate of Engineering. Research Institute of Railway Transport, Moscow

Special Aspects of Railway Roadbed Stability Calculations After Its Strengthening by Electrochemical Treatment Victor Ganchits , Evgenii Chernyaev , Victoriia Cherniaeva and Nataliia Panchenko

Abstract The article presents the results of the theoretical researches in the field of railway roadbed stability calculation. The article considers the influence of soils stabilized by electrochemical action with the application of electrolytes on the specific features of stress–strain state with consideration of the dynamic effect from rolling stock. It gives a brief method of stability calculation taking into account the specific features of electrochemically treated soils. The developed method allows taking into account the reduction of strength characteristics of soil under dynamic effect from rolling stock. The described methodology is based on the data of field and laboratory studies which allow evaluating the actual levels of vibrodynamic impact on the soils of roadbed from passing trains and the sensitivity of certain soils to this effect. It also provides for a preliminary selection of the composition of the electrolyte and the modes of passing direct electric current in the laboratory conditions. This allows having a better consideration of the characteristics of soil received after electrochemical treatment in the calculation. Keywords Electrochemical treatment · Electric osmosis · Clay soils · Stress–strain state · Roadbed · Assessment of stability

1 Introduction It is known that electrochemical treatment can be one of the effective methods of improving the physical and mechanical properties of cohesive soils with filtration coefficient of less than 0.5 m/day [1–4]. It means that specific composition electrolytes are placed into the soil through the electrodes simultaneously with passing through the soil. Soil properties are changed as a result of exposure to direct electric current. At the same time, new cementing substances are synthesized in the zone of microaggregates contact and/or on the surface of particles. The particles include V. Ganchits (B) · E. Chernyaev · V. Cherniaeva · N. Panchenko Emperor Alexander I St. Petersburg State Transport University, Moscovsky Prospect 9, St. Petersburg 190031, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_40

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both the products of new formations obtained in a result of chemical reaction and the component parts of fine mineral particles. Change in the chemical composition of the absorbed complex and other phenomena take place that causes changes in the original properties of soil. It happens as a result of various physicochemical processes involving the electrolyte components in the soil, soil draining, and coagulation of the fine particle fraction in the electrode zones. The listed processes and reactions contribute to intensive change in the physical and mechanical properties of the initial clay soil, transforming its performance characteristics to the values comparable with soil suitable for construction [5]. In the course of laboratory studies, electrolyte compositions have been obtained based on orthophosphoric acid with the addition of zinc oxide [6–18]. For the purpose of performance and effectiveness test verification, it was necessary to conduct field studies at a section of operated railway roadbed. For this reason, it was necessary to develop a method for roadbed calculation, which allows determining the zones in which electrochemical treatment will produce the greatest effect.

2 Development of Roadbed Electrochemical Strengthening Calculation Method The following basic provisions have been taken as the basis: 1. The stability calculation of slope strengthened by electrochemical treatment of clay soils should be carried out for the most adverse operational conditions of the roadbed. 2. The calculation may be based on identifying the possible sliding curves on a circular-cylindrical surface. This method is accurate enough to receive reliable results. 3. When calculating the stability of embankment slopes, it is necessary to take into account the influence of the dynamic load which is characterized by the value of oscillations amplitude at the sleeper ends of on the level of subgrade top during the freight trains passage with maximum speed and maximum axle and linear load [19]. Taking into account the principles adopted above, the procedure for calculating the roadbed slope stability should be as follows: 1. The block of possible displacement of the massif is divided into a number of sections with a width of max 2 m. The load from the track superstructure and train is taken into account by a fictitious column of soil. The coordinates of points Z and Y are determined on the slip line at the middle of the section. For these points, the operating amplitudes of oscillations Azy are determined, which are taken into account in the further calculation.   A zy = Ao exp zlgδ1 − δ2 1 ϕ(y) − δ22 ϕ(y) − δ3 h i , μm

(1)

Special Aspects of Railway Roadbed Stability Calculations …

391

where Ao is the amplitude of the roadbed oscillation at the level of subgrade, μm (can be measured for a specific stretch or taken according to reference values); δ 1 , δ 12 are oscillation attenuation coefficient in vertical and horizontal planes, respectively, 1/m; δ 22 is surface waves attenuation coefficient, 1/m; δ 3 is the oscillation attenuation coefficient in the embankment body, 1/m; δ3 =

lg δ1 , 1/m 1.5m i

where mi is a gradient of slope i; hi is the height of slope i, m. ⎡

0 for |y| ≤ 0.5bst ⎣ h i = y − 0.5bst for |y| > 0.5bst mi where bst is the width of subgrade top, m; ⎡

0 for |y| ≤ 1.35 φ(y) = ⎣ |y − 1.35| for 1.35 < |y| ≤ 9 |y| > 9 7.65  0 for |y| ≤ 1.35 φ 1 (y) = y − 1.35 for |y| > 1.35 where Z, Y are the reference point vertical and horizontal coordinates in relation to a point located along the track centerline at the level of subgrade top. 2. The values of obtained amplitudes determine the values of the strength characteristics of clay soils that are induced to oscillations with amplitude Azy . Their reduction under the influence of vibrodynamic effects from passing trains taking into account with the following equations     Cdn = Cst K c + K c exp −K A zy −Ain , kN/m2

(2)

   ϕdn = ϕst K j + K j exp −K A zy , deg

(3)

where C dn , ϕ dn are the cohesion and internal friction angle of the soil induced to oscillations with Azy amplitude. C st , ϕ st are the cohesion and internal friction angle, upon the action of the static load; K c , K ϕ are minimum ratios of the characteristics of cohesion and internal friction angle

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Cmin Cst

(4)

φ K φ = min φst

(5)

Kc =

C min , ϕ min are the lowest values of cohesion and internal friction angle, respectively, determined in test with the highest vibrodynamic load; Ain is the initial amplitude of oscillations, at which the decrease in characteristics does not exceed 3–5% microns; K c , K ϕ are maximum values of strength characteristics relative decrease. Kc = 1 − Kc; K j = 1 − K j

(6)

K is coefficient of vibrational destruction during soil triaxial compression testing. The values of C min , ϕ min should be determined by testing the soils in a triaxial compression apparatus with a stress pulsation of at least 0.03 MPa. 3. For the slide curve, the stability coefficient is determined by the equation n K st =

i=1

1 1 tgφdn N i + Cdn li + Tir n i=1 Tis

(7)

where li is length of section i in the plane of displacement, m; N i is axial force of section i, kN; T ir , T is are respectively restraining and shearing force of section i, kN. Similar calculations are used to find the surface of possible slide with a minimum stability coefficient. Stability coefficient for the calculated sliding surface is compared with the tolerable value [K st ]. If K st < [K st ], then the activities for increasing the slope stability are to be appointed.

3 Determination of Clay Soil Massif Location for Stabilization by Electrochemical Treatment The width of the zone to be stabilized is appointed based on the optimal arrangement of the electrodes. The initial depth of the zone to be stabilized is taken from the condition that the calculated sliding surface intersects the stabilized massif. The slope stability coefficient is determined taking into account the strength characteristics of the stabilized soil massif. The values of strength characteristics of stabilized soil are taken according to the preliminary laboratory studies necessary to select the optimal composition of electrolyte and the mode of electric current transmission. It is possible to take the data shown in Table 1 as reference values. The

2.71

2.7

2.73

Heavy silty clay loam

Light silty clay loam

Heavy sandy clay loam

1.76

1.6

1.75

Specific Dry weight, unit g/cm3 weight

Soil

20.2

25.5

15.2

33.4

30.6

32.7

16.5

18.8

17.1

Maximum Plasticity moisture Limit Limit capacity of liq- of uidity plasticity

16.9

11.8

15.6

0.2

0.1

2.1

59.7

2

11.2

Plasticity Grain size distribution index Jp >2.0 mm 2.0–0.25 mm

Table 1 Physical and mechanical characteristics of soils subjected to electrochemical treatment

9.6

8

11.1

0.25–0.05 mm

2.3

61.5

15.8

0.05–0.01

6.1

18

30.7

0.01–0.002

22.1

10.4

29.1

< 0.002

Special Aspects of Railway Roadbed Stability Calculations … 393

0.09

0.005

15

Kϕ

K

A(μm)

0.45

10

0.01 5

0.015

0.10

0.13

>0.45

20

0.06

0.10

0.20

0–0.15

0.55

0.15–0.45

0–0.15

0.15

Clay loams

Clays

Name of soil and its moisture content

Kc

Description

7

0.011

0.40

0.50

0.16–0.45

Table 2 Physical and mechanical characteristics of soils subjected to electrochemical treatment

0

0.02

0.08

0.15

>0.45

25

0.006

0.07

0.1

Hard

Sandy loams

0

0.025

0.40

0.60

Plastic

30

0.003

0.05

0.10

Stabilized soil

394 V. Ganchits et al.

Special Aspects of Railway Roadbed Stability Calculations …

395

values of K c , K ϕ , K, An are also desirable to receive directly from laboratory studies, but the values from Table 2 can be used. If the obtained stability coefficient is less than the tolerable value, the calculation is repeated, increasing the width of stabilized zone. The depth of treated soil mass is to be determined from the condition of a soil displacement possibility absence along the surfaces passing through the bottom of soil being stabilized or lower. With the stability coefficient on the specified displacement surfaces less than tolerable, it is necessary to increase the depth of the treated soil or change the pattern of strengthening strips.

4 Conclusion The developed calculation method of roadbed stability stabilized by electrochemical treatment allows taking into account the strength characteristics reduction of soil under dynamic load from rolling stock [20, 21]. The described methodology is based on the data of field and laboratory studies which allow evaluating the actual levels of vibrodynamic impact on the roadbed soils from passing trains and the sensitivity of certain soils to this effect. It also provides a preliminary selection of the composition of the electrolyte and the modes of direct electric current passing in the laboratory conditions. This allows having a better consideration of the soil characteristics received after electrochemical treatment in the calculation. Application of this method allows determining the optimum zone in which the electrochemical treatment will give the best effect from the standpoint of ensuring the stability of roadbed.

References 1. Rebinder PA Structural and mechanical properties of argillous rock and modern concepts of physical and chemical colloids. In: Proceedings of the Meeting on engineering and geological properties of rocks and methods of their study, vol 1. Publishing House of the Academy of Sciences of the USSR, Moscow 2. Rachmasyah A (2002) Soil improvement with electroosmosis method. Research Report, Toray Foundation 3. Zhinkin GN (1966) Electrochemical soil stabilization in construction. Stroyizdat, Leningrad 4. Rachmansyah A, Zaika Y (2010) Model Test Perbaikan Tanah Dengan Metode Injeksi Elektrokimia, Konferensi Teknik Sipil 4, Denpasar, Bali, Juni 2010 5. Zhinkin GN, Sergeyenkova KK (1970) About some chemical processes occurring in clay soils when exposed to direct electric current. In: Proceedings of meeting on theoretical basics of technical soil reclamation. Publishing House of Moscow State University 6. Ganchits VV (2003) Use of phosphate electrolytes for electrochemical soil stabilization of railway roadbed. Adv Technol Railway Transp Ind 3 7. Correia AG, Momoya Y, Tatsuoka F (2007) Design and construction of pavements and rail tracks: geotechnical aspects and processed materials. Taylor and Francis, London

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8. Correia AG, Quibel A, Winter MG (2012) The work of ISSMGE TC3 (geotechnics of pavements) and how it links to earthworks. Geological Society Engineering, Engineering Geology Special Publications (EGSP) (26), pp 67–77 9. Esveld C (2001) Modern railway track. MRT Press, The Netherlands 10. Huang H, Tutumluer E (2011) Discrete element modeling for fouled railroad ballast. Constr Build Mater 25(8):3306–3312 11. Indraratna B, Salim W, Rujikiatkamjorn C (2011) Advanced rail geotechnology—ballasted track. CRC Press/Balkema 12. Indraratna B, Thakur PK, Vinod JS (2010) Experimental and numerical study of railway ballast behaviour under cyclic loading. Int J Geomech ASCE 10(4):136–144 13. Indraratna B, Ngo NT, Rujikiatkamjorn C, Vinod JS (2012) Behaviour of fresh and fouled railway ballast subjected to direct shear testing—a discrete element simulation. Int J Geomech ASCE (accepted, in press) 14. Lobo-Guerrero S, Vallejo LE (2006) Discrete element method analysis of railtrack ballast degradation during cyclic loading. Granular Matter 8:195–204 15. Lu M, McDowell GR (2006) Discrete element modelling of ballast abrasion. Géotechnique 56(9):651–655 16. McDowell GR, Harireche O (2002) Discrete element modelling of soil particle fracture. Géotechnique 52(2):131–135 17. Yang LA, Powrie W, Priest JA (2009) Dynamic stress analysis of a ballasted railway track bed during train passage. J Geotech Geoenviron Eng ASCE 135(5):680–689 18. Chai JC, Miura N (2000) Traffic load induced permanent deformation of low road embankment on soft subsoil. In: Proceedings of international conference on geotechnical and geological engineering. CD Rom, Paper No. DE0239 19. Ganchits V, Cherniaeva V (2017) Study of phosphates use in electrochemical treatment of water-saturated argillaceous soils. Procedia Eng 189 20. Dobry R, Vucetic M (1987) Dynamic properties and seismic response of soft clay deposits. In: Proceeding of international symposium on geotechnical engineering of soft soils. Mexico city, pp 51–87 21. Elias V, Welsh J, Warren J, Lukas R, Collin JG, Berg RR (2004) Ground improvement methods. Participant Notebook. NHI Course 132034. FHWA NHI-04-001. Washington D.C.

Features Transport Planning the Network of Municipal Roads in Northern Region Pavel Pegin, Alexey Ilyin

and Ksenia Semenova

Abstract The article briefly presents the rationale for the choice of the region in order to be able to use the existing parameters of the assessment of the network of municipal roads. To make the estimation of municipal highway network with consideration for geographical particularity (cold region) objective, we suggest a method with additional specifications. One of them is L  total highway working mileage, km. The proposed amendments to the existing assessment parameters will make it possible to estimate the state of the road network in researched region more effectively. Keywords Road network · Length of municipal and local roads · Assessment of the transport network · Density of the road network · Northern region

1 Introduction Leningrad region stretches approximately 320 km from the north to the south and almost 500 km from the west to the east. It is situated on the East European Plain. The largest uplands are: Izhora Upland, Lembolovo Upland, Lodeynoe Pole Upland, Veps Upland, and Tikhvin range. Lowlands are situated on the banks of the Gulf of Finland and Ladoga Lake, as well as in the valleys of large rivers [1]. Combination of mentioned above terrain and landscape influenced on the development of road network in Leningrad Region. Apart from historical and geographical factors, the formation of the road network was influenced by its location to St. Petersburg, which is a large transport multimodal center of land, river, sea, and air means of communication. Although average temperature in January in Leningrad Region is between −7 and −11 °C, statistics, based on annual researches, says that the least temperatures reached −50 °C, and the height of snow cover was about 50 cm (Fig. 1). P. Pegin · A. Ilyin (B) · K. Semenova Emperor Alexander I Petersburg State Transport University, Moscow Avenue 9, Saint-Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_41

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Fig. 1 Isotherms of January and bare minimum on Leningrad Region territory

Total railway mileage in Leningrad Region is 5 times longer than on an average in the rest of Russia, and is about 3000 km (2). Motorway density in western parts of Leningrad Region is higher in comparison with eastern parts, where average winter temperature is 2–3 °C less [2]. Motorway network density is 4 times higher than on the average in the rest of the country. To sum up all mentioned above, we should say that this region may be referred to cold regions with large railway mileage and motorway network density. Existing and proposed parameters for the evaluation of the municipal road network. To estimate municipal motorway network in northern regions, based on cooperation with other types of transportation (railroad, water, and air transport), represented in the region, we suggest using the following aspects: Highway mileage (both regional and federal) Railroad mileage Availability of navigable waters Presence of airports Presence of road-vehicle depose Presence of transport hubs. In existing methods of estimation of condition of transport network of a region, such aspects as the following ones are used:

Features Transport Planning the Network of Municipal Roads …

– – – –

399

density of means of communication (formula 1), density of network (formula 2), Engel coefficient (formula 3) [3], Golts coefficient (formula 4):

Ps =

L twm · 1000 s

(1)

L twm —total working mileage, km; S—square footage of a region. Pp =

L twm · 10000 H

(2)

where, P—population;

d=

L twm Ka = √ s·H

(3)

L twm + L rm + L w √ S×n

(4)

where, n—quantity of settlements; L rm —railroad mileage; L w —navigable waters mileage. To make the estimation of municipal highway network with consideration for geographical particularity (cold region) objective, we suggest a method with additional specifications. One of them is L twm total highway working mileage, km. In November 2013, Government of Leningrad Region accepted a state program “Development of motorways in Leningrad Region” [4], due to which number of settlements dealt with hard-surfaced highway network throughout the year must be increased. Today, the number is 72.8% (Fig. 2). 73 72.8

%

72.6 72.4 72.2 72 71.8 2013

2014

2015

2016

2017

Years

Fig. 2 Percent of settlements dealt with hard-surfaced highway network throughout the year in Leningrad Region

400

P. Pegin et al. 0.3 2017, 0.27

0.25

%

0.2 0.15

2014, 0.165

2015, 0.165

2016, 0.18

2016, 0.165 2017, 0.165

2014, 0.14

0.1 2015, 0.07

0.05 0 2013

2014

2015

2016

2017

2018

Years Fig. 3 Annual percentage growth of settlements dealt with hard-surfaced highway network throughout the year in Leningrad Region

Percentage growth of settlements dealt with hard-surfaced highway network throughout the year is annually increasing in average up to 0.5% (Fig. 3). This can lead to conclusion that during rather a considerable period of time, there will be no connecting motorways between roads with permanent and semi-prepared types of surfaces. According to existing classification of roads by type of surface, roads with nonhard surfaces are classified as transitional or lower roads. In case of construction technology and operation violation, traffic is difficult or completely impossible on such roads in spring and autumn. Therefore, for communication with settlements either other routes (if any) or alternative means of communication (water transport is used more often than air). In each district of the Leningrad Region, there are small settlements [5] with population of less than 50 people. In case of absence or difficulties of direct communication (water barriers) in spring–summer–autumn period, ferry or pontoon crossings are used for their transportation; in winter, with appropriate preparation, they use temporary routes—“winter roads”. To conclude, it can be said that highway network mileage, as well as navigable water mileage may vary in different periods of the year. Therefore, in order to assess its condition, in relation to the cold regions, it is necessary to introduce amendments to the total working mileage and navigable water mileage. We suggest replacing of L twm —total working mileage km with, where L twm = temp L total twm ± L twm are total working of permanent and temporary road, km. With the amendments, formulas 1, 2, 3 and 4 will look as follows temp

Ps =

L total twm ± L twm · 1000 s

Pp =

L total twm ± L twm · 10000 P

(5)

temp

(6)

Features Transport Planning the Network of Municipal Roads …

401

temp

Ka =

L total twm ± L twm √ s·P

temp

d=

(7) temp

total L total twm ± L twm + L rm + L w ± L w √ S×n

(8)

2 Conclusion The proposed amendments to the existing assessment parameters will make it possible to estimate the state of the road network in researched region more effectively. Based on the analysis, promising measures for increasing the capacity and mobility of the population should be developed, as well as traffic safety should be improved [6], which is very important for regions with severe weather and climate conditions.

References 1. Darinsky AV, Frolov AI (2008) Geography of Leningrad Region, 248 2. Pegin PA, Ilyin AA (2018) Article improving the network of municipal roads (on the Example of Leningrad Region). Infocommunicational and Intellectual Technologies in Transport, 154–156 3. Stroeva GN, Slobodchikova DV (2016) Provision the Transport availability of the population as an important direction of socio-economic development of the region. On-line scientific editorial «Scientific Notes of Tomsk State University», 673–679 4. About passing of State program of Leningrad Region “Development of Roads in Leningrad Region”, № 397 (2013) 5. Urbanism, Planning and Construction of Town and Rural Settlements. LR 42.13330.2011 Upto-dated constructional rules and regulations 2.07.01-89* (2018) 6. Pegin PA, Carev VF, Careva VV (2016) Providing traffic safety in difficult climate conditions, 212–215

Bearing Capacity of High Embankment Clay Soils in Terms of Heavy Axle Load Operation Alexey Kolos, Andrei Romanov, Evgeniy Shekhtman, Gennadii Akkerman, Anastasia Konon and Artyom Kiselev

Abstract The paper describes results of bearing capacity calculations for railway clayey embankment under new generation gondola cars with 270 kN axle load. Test stretch is situated at the eastern slope of Ural Mountains. The area has average year temperature of 1.7 °C. Vertical deformations were measured in October 2017–July 2018 for one control section and three test stretches made up with new generation cars and under regular freight trains. It was found that one test stretch had great residual deformations (up to 25 mm). Calculations were performed of critical load and total stresses on the top of the clay layer for summer and spring (period of thawing). For spring, when great deformation occurred, the safety margin was 1.08 times, while the average residual deformation of the subgrade top amounted 11.8 mm. This case study confirms the importance of special track preparations. It was obtained that clayey subgrade had 33% less critical load during the thawing period. It had lead to great deformations under cars with 270 kN axle load. Keywords Heavy axle load · Clayey subgrade · Critical load · Case study

1 Introduction Axle load increasing of freight rolling stock is a key development direction for railways in the world. Heavy axe load operation has become widespread on different continents. In Australia, the axle load of a freight car reaches 37.5 tons, and the train weight exceeds 48 thousand tons. North American railways introduced heavy traffic in the late 1990s. To date, the axial load in the USA is 32 tons, in some areas it amounts 36 tons, and the train weight exceeds 20 thousand tons. In the Republic of South Africa, trains weighing 40 thousand tons run with an axle load of 30 tons. Chinese railways are introducing the technology of driving trains weighing 30 thousand tons [1]. A. Kolos · A. Romanov · E. Shekhtman · G. Akkerman · A. Konon (B) · A. Kiselev Emperor Alexander I St. Petersburg State Transport University, Moskovsky pr., 9, St. Petersburg 190031, Russian Federation e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_42

403

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In Russia, the development of heavy axle load operation was carried out mainly by increasing the train length and maintaining twin trains. But for making up such a train, it is required to extend the receiving and departure tracks at the stations. It requires significant investments in the railway infrastructure modernization. New generation gondola cars produced by Research and Production Corporation “United Wagon Company” (RPC UWC) will allow trains with a total weight of 7100 tons to be launched, and over 11 thousand tons in some areas. It will be possible to transport 20% more cargo, preserving the unified train length of 71 car. In 2017–2018, tests have been conducted at the Sverdlovskaya Railway of new generation rolling stock produced by “United Wagon Company”. JSC Railway Research Institute (VNIIZhT), JSC VNIKTI, Emperor Alexander I Petersburg St. Petersburg State Transport University, Russian University of Transport (MIIT), Research Institute of Bridges and Flaw Detection and other leading institutes and testing centres took part in the tests. The test aims were: • monitoring the state of the infrastructure, • assessing the deterioration accumulation in the track superstructure and subgrade deformations, • developing standards for the design, operation, maintenance, diagnostics of the infrastructure, and train driving technologies.

2 Materials and Methods During tests, assessment of residual deformations accumulation was performed in the sections in the middle of continuous welded track string, in the middle of jointed track panel and at the joint section under cars with 230 and 270 kN axle load during October 2017–July 2018. The tests were carried out on four double-track electrified stretches: sections 1–3 were operated with traditional rolling stock formed of cars with 230 kN axle load and new generation cars with 270 kN axle load, and section 4 (control section) was operated only with traditional 230 kN cars. Continuous welded track has been laid with concrete sleepers and crushed stone ballast on the main track I of test sections 1–3. On the main track II, there is a jointed track on wooden sleepers and asbestos ballast. Main track I of section 4 is a jointed track on wooden sleepers and asbestos ballast. Main track II of section 4 is a continuous welded track on concrete sleepers and crushed rock ballast. The speed of the new generation and traditional rolling stock during the test period ranged from 30 to 70 kmph. To determine subgrade residual deformations, a geodetic reference height base was created at the test site. Within the railroad right of way, 12 bench marks were

Bearing Capacity of High Embankment Clay Soils …

405

arranged. Three marks were placed at each test section. The level net basis for determining the subgrade top settlement at each section was created by creating a complete levelling line on the bench marks. Each test section is equipped with 21 ground bench marks, installed on the subgrade top. For the ground bench marks installation, pits of at least 45 cm depth were constructed. An example of the layout of stamps is shown in Fig. 1.

Fig. 1 Installation of bench marks on test sections

406

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3 Deformations of Measurements Results for Subgrade Top and Discussion In the period of December 2017–July 2018, eight cycles of geodetic control of subgrade top deformations were carried out. Basing on test data, the following main results were obtained: 1. At the control section, where new generation cars do not run, there are no residual deformations. 2. Intense frosty swelling was observed at test sections 1 and 2 during the winter period. By the time of the last measurement, the subgrade was completely thawed. The average total accumulated deformation of subgrade top is comparable with the value for the control section. By the last measurement, the accumulation of residual deformations had almost stabilized. 3. At test section 3, an intense rise of residual deformations was observed, which accelerated during the subgrade thawing. By the time of the last measurement, the intensity of residual deformations accumulation of subgrade top has significantly decreased. The measurement results of residual deformations at test sections 1–4 are given in Table 1. At section 3 maximum deformations were observed in terms of new generation cars operation. Subgrade top stressed state measurements showed that the values of the maximum vertical stress in the underrail section at a speed of 30–40 kmph amounted to 87 kPa and exceeded the limiting stress of 80 kPa [2] on the track with concrete sleepers on crushed stone ballast at subgrade top (45 cm below the sleeper). The appearance of vertical stresses of more than 80 kPa induced by train impact at the subgrade top is a criterion for the occurrence of residual deformations of the clayey soil subgrade. Thus, vertical stresses appearance should be excluded exceeding clayey soil subgrade bearing capacity at railway lines operated with new generation cars with 270 kN axle load. The presence of clay soils in the subgrade can be a deterrent to bringing into service cars with increased carrying capacity due to significant changes of clay mechanical properties during periods of seasonal freezing and thawing.

4 Bearing Capacity Evaluation of Subgrade Clay Soils To determine the vertical stresses induced in clayey subgrade, the dependence obtained by G. G. Konshin is taken [3]. To prevent the plastic deformation occurrence, a subgrade in soils at a depth h of plastic (residual) deformations in subgrade, the total stresses from train load, the weight of the track superstructure and its soil weight should not exceed the critical load for the soil. The critical load is evaluated according to Puzyrevsky formula [4]:

0

Maximum

4 (control section)

3

2

0

Average

1

0 0

Maximum

0

Maximum

Average

0

0

Maximum

Average

0

Average

05.12

– 0.8

0.0

– 4.6

– 1.6

29.1

6.9

1.8

0.8

30.01

Measurement date

– 1.2

– 0.3

– 6.7

– 1.7

33.7

10.3

11.1

6.0

15.03

– 1.4

– 0.1

– 8.8

– 1.9

39.0

14.5

14

6.5

12.04

– 1.6

– 0.5

– 14.1

– 4.3

32.5

10.1

11.6

5.3

08.05

– 2.8

– 1.3

– 17.8

– 7.1

21.9

5.9

9.4

2.9

22.05

– 3.4

– 1.4

– 20.6

– 7.9

– 5.0

– 2.4

– 4.6

– 1.9

19.06

The difference in bench mark level, compared to initial value, measured on 05.12.2017, mm

Deformation type

Test section

Table 1 Measurement results of residual deformations

– 3.0

– 1.6

– 22.5

– 8.7

– 4.4

– 1.5

– 5.0

– 2.0

19.07

Bearing Capacity of High Embankment Clay Soils … 407

408

A. Kolos et al.

σh ≤ pcr =

π (c · ctgφ + γ h) + γh ctgφ + φ − π2

(1)

where σh —total vertical stress from train load, weight of the track superstructure and its soil weight in subgrade active area at the depth of h, m, under the sleeper, kPa; pcr —critical load for the given soil, kPa; c—cohesion of the soil, taken regarding the reduction due to spring thawing, kPa; ϕ—internal friction angle; γ—density of the soil upper the depth of h, kN/m3 . Clayey soil cohesion is calculated for the thawing period according to the equation [5]: cth =

c − Bf Kc

(2)

gde cth —cohesion of thawing soil, kPa; c—cohesion of thawing soil for summer and autumn obtained after laboratory tests, kPa; K c —coefficient of cohesion decrease after thawing due to dynamic load [5]; B—coefficient of strength reduction due to frost heave B = 70; f —frost heave intensity according Russian design standards. Tables 2, 3 and Fig. 2 present the calculation results of the critical load for all test sections where the innovative rolling stock has been run. Table 2 shows the calculation results of critical load for the summer period and period of thawing (spring). Table 3 shows a comparison of critical load, total stresses imposed to clay soils in the subgrade, as well as maximum values of the vertical residual deformations of the subgrade top of the main track I with concrete sleepers. Table 3 data analysis shows that in most cases, the critical load exceeded total stresses in clay soil. At test sections 1 and 2, safety margin was at least 1.5x and 1.2x during new generation rolling stock running along the main track I and II, respectively, and residual deformations did not exceed 2.5 mm. At test section 3, the safety margin was 1.08 times, while the average residual deformation of the subgrade top amounted 11.8 mm at the main track I during thawing period for new generation cars operation. The critical load on the clay soil and total stresses were close in value with a higher critical load (83 kPa and 77 kPa, respectively) during new generation cars operation with 270 kN axle load. This fact explains the great residual deformation of subgrade top at test section 3.

5 Conclusions This paper shows the case study that confirms the importance of special track preparations. It was obtained that clayey subgrade had 33% less critical load during the thawing period. It leads to great deformations under cars with 270 kN axle load.

25.0

16.7

15.7

2

3

19.7

18.3

16.7

0.7 0.75

0.75

156 124

123 1.30

1.10

1.14 70

70

70

B

0.028

0.028

0.027

f

Ks

pcr , kPa

Spring (period of thawing) h, m

S, kPa

ϕ, degree

Summer

Season

1

Test section

Table 2 Critical load on the top of the clay layer, pcr , kPa

10.1

13.2

20.0

C om , kPa

17.1

15.9

14.5

ϕ, degree

0.75

0.75

0.70

h, m

83

95

121

pkr , kPa

Bearing Capacity of High Embankment Clay Soils … 409

270

230

Test section 3

270

230

Test section 2

270

230

Test section 1

Axle load, kN

124

60

124

70

124

124

60

40

124

40

123

70

123

70

123

123

60

60

123

156

70

50

156

156

60

156

70

83

83

83

83

83

95

95

95

95

95

121

121

121

121

49

48

41

40

39

50

49

41

40

39

53

52

43

42

16

16

16

16

16

16

16

16

16

16

16

16

16

16

Stress from superstructure weight, kPa

Stress from train impact, kPa

Summer

Spring (period of thawing)

Operating total stress, σh , kPa

Critical load on the top of the clay layer, pcr , kPa

60

Speed, kmph

12

12

12

12

12

12

12

12

12

12

11

11

11

11

Stress from soil weight, kPa

Table 3 Critical load and total stresses for clay. Vertical residual deformations of the subgrade top

77

76

69

68

67

78

77

69

68

67

80

79

70

69

Total stress σh , kPa

pcr σh

1.61

1.63

1.80

1.82

1.87

1.57

1.59

1.78

1.81

1.83

1.94

1.97

2.22

2.25

Summer

Ratio

1.08

1.09

1.21

1.22

1.25

1.21

1.23

1.37

1.39

1.41

1.50

1.52

1.72

1.74

Spring (period of thawing)

11.8

2.5

2.5

Average residual deformation of subgrade top, mm

410 A. Kolos et al.

Bearing Capacity of High Embankment Clay Soils …

411

Fig. 2 Comparison of critical load and operating stress for clayey subgrade under cars with 230 and 270 kN axle load

Test results show that in some cases, clayey embankments and cuttings can be barrier sites for organizing heavy axle load operation. Operating these stretches with cars of 270 kN axle load and higher may lead to significant acceleration of residual deformations accumulation without measures to strengthen the subgrade [5–12].

References 1. Zakharov SM, Kharris U, Landgren D, Turne Kh, Eberson V (2015) Guidelines to best practices—management of the wheel and rail interface. USA 2. Technique for assessing the impact of rolling stock on the road in terms of ensuring its reliability. Moscow (2000) 3. Konshin G (2012) Subgrade performance under train impact. Training Center on education in railway transport, Moscow 4. Maslov NN (1982) Basics of engineering geology and soil mechanics. High school, Moscow 5. Kolos A, Konon A (2016) Estimation of railway ballast and subballast bearing capacity in terms of 300 kN axle load train operation. In: Zhussupbekov A (ed) Proceeding of the international conference on Challenges and Innovations in Geotechnics. Balkema, Rotterdam, Astana, 5–7 Aug 2016 6. Petryaev A, Morozova A (2013) Railroad bed bearing strength in the period of thawing and methods of its enhancement. Sci Cold Arid Reg 5(5):548–553 7. Vorster DJ, Gräbe PJ (2013) The effect of axle load on track and foundation resilient deformation under heavy haul conditions 8. Leng W, Mei H, Nie R, Zhao C, Liu W, Su Y (2018) Full-scale model test of heavy haul railway subgrade. J Vib Shock 37(4) 9. Li D (2018) 25 years of heavy axle load railway subgrade research at the Facility for Accelerated Service Testing (FAST). Transp Geotech 17:51–60 10. Kalay S, LoPresti J, Davis D (2011) Development of Enabling technologies for heavy axle load operations in North America. 9th World congress on railway research, Lille

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11. Giner IG, Alvarez AR, Sánchez-Cambronero García-Moreno S, Camacho JL (2016) Dynamic modelling of high speed ballasted railway tracks: analysis of the behaviour. Transp Res Procedia 18:357–365 12. Mei H, Leng W, Nie R, Liu W, Chen C, Wu X (2019) Random distribution characteristics of peak dynamic stress on the subgrade surface of heavy-haul railways considering track irregularities. Soil Dyn Earthq Eng 116:205–214

Research on Frost Protective Layers for Railways Vladislav Yurkhanov, Dmitriy Serebryakov, Evgeniy Shavrin and Anastasia Konon

Abstract Foam glass aggregates, a granular material made from recycled glass of various origins, are among these new products. Problems of managing glass residue have several origins: contamination from the recovery step, ineffective grading technology and low economic value of the final product. These problems limit the incentives to invest in the recycling of waste glass. Test study of frost protection layer structures was performed on Russian Railway Research Institute experimental track in Moscow. Cellular materials used for protection layers were FGA ballast and XPS panels. Obtained results show that FGA ballast can be used in protective layer. It is suitable for installing on wetted and less stiff subgrade sections (with a deformation modulus less than 50 MPa). Installation of geotextile at the top and bottom of protection layer is advised to achieve requires stability and water erosion tolerance. Keywords Foam glass aggregates · Frost protective layers · Water erosion

1 Introduction Russia is one of the most northern-situated countries in the world. Its geographical center is only 16 km to the South from the North Pole. About 65% of Russian Federation area is situated in the permafrost region. This region is characterized with extremely continental climate with long frosty winter and short hot summer, over moist and swamped territory and adverse geological conditions. Also, seasonal freeze-thaw of over moist subgrade top occurs, which may be followed with frost heaving and forming of ballast pockets and local slope deformations. These slope instabilities are associated with the division plane of thaw and V. Yurkhanov · E. Shavrin Materials and Structures Test Center, JSC RZD, Rybinskaya str., 4, St. Petersburg 192007, Russian Federation D. Serebryakov · A. Konon (B) Emperor Alexander I St. Petersburg State Transport University, Moskovsky pr., 9, St. Petersburg 190031, Russian Federation e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_43

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Table 1 Deformation moduli and thickness of substructure layers Layer type

Layer thickness, cm

Deformation modulus, MPa

Ballast

40

160–180

Crushed stone, gravel and sand mix (protective layer)

40

100–120

Frost protection layer (not more than)

50

80

130

60

50

40

Top of subgrade Bottom of subgrade

frozen soil. This effect introduces complications in railway maintenance. Railway operation in Russia and all over the world shows that frost protection layer is needed in substructure [1, 2]. Frost protection layers are constructed with XPS panels and geotextile according to JSC RZD requirements. Protective layers can also be constructed with granular soils [3]: gravel and medium sands, cobbles with sand, riddlings of crushed stone manufacturing. Sub ballast layers of railways can be constructed from sand and gravel mix with a natural grain particle size, crushed gravel, crushed stone with specific grain size, sand and gravel mix with optimal rain size according to JSC RZD requirements. At the same time, according to stress distribution in track substructure and superstructure, deformation modulus of substructure layers should increase from bottom to top, and layer thickness should decrease (Table 1). Provision of these parameters for operating lines is made during reconstruction. Bearing capacity of substructure layers depends significantly on the quality of the upper layer gutting during compaction. As ballast density rises (and porosity decreases), keying strength increases. Foam glass aggregate (FGA) can be used as a frost protection layer material because of good thermal insulating properties. A layer of foam glass aggregate also ensures good gutting after layer-wise compaction [4–9].

2 Materials and Methods Test study of frost protection layer structures was performed on Russian Railway Research Institute experimental track in Moscow. Cellular materials used for protection layers were FGA ballast and XPS panels. Test sections layout is shown in Table 2. Test section is a stretch of tangent line at least 250 m long (Fig. 1).

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Table 2 Test sections of subballast protection layer structures Structure type

Test stretch, m

Crushed stone ballast of 45 cm under the sleeper, XPS panels

50

Crushed stone ballast of 45 cm under the sleeper, FGA of 25 cm

50

Crushed stone ballast of 25 cm under the sleeper

50

Crushed stone ballast of 15 cm under the sleeper, 1500 sleepers per km

150

Crushed stone ballast of 45 cm under the sleeper, 1640 sleepers per km

50

3 Results and Discussion Specimens were taken from test sections after 600 millions tons of gross weight. Moisture content and deformation moduli of protection layer structures were assessed. Moisture content of material W, % was calculated with equation W =

mm − m 100, m

(1)

where m m is soil mass with water, g, m— mass of dry soil, g. Moisture content for test structures is shown in Table 3. Deformation moduli for test structures are shown in Table 4. Obtained results show that FGA ballast can be used in protective layer. However, since XPS panels are much softer (Table 4) and have a large water absorption value (Table 3), it is recommended to place them on a stiff subgrade (with a deformation modulus of at least 50 MPa) and in areas with a dry climate. Since the FGA ballast is stiffer than XPS panels material (Table 4) and has a lower water absorption value (Table 3), it is suitable for installing on wetted and less stiff subgrade sections (with a deformation modulus less than 50 MPa). However, it should be noted that construction of protection layers in these conditions also requires the mandatory measures to prevent water erosion. V cr is the critical scouring velocity to break the ballast layer and it is calculated with the Eq. (2):  Vcr =

2[Fc + mg f (cos α − sin α)] C x (Re)Sρ

where F c is ballast particles cohesive force, M—an average mass of ballast particle of used size, G—free fall acceleration (9,8 m/c2), f —static coefficient of friction for ballast particles, α—slope angle (degree),

(2)

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Fig. 1 Longitudinal section and cross-sections of tangent stretch with test protective structures

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Table 3 Moisture content for test structures Parameters

Test structures XPS panels

15 cm of FGA ballast

25 cm of FGA ballast

50 cm of FGA ballast with geogrid

FGA ballast on the border of 25 cm and 50 cm sections

Soil mass with water, g

62.65

69.76

417.09

187.41

157.27

Dry soil mass, g

49.17

62.03

383.85

175.88

143.50

Moisture content, W, %

27.42

12.46

8.64

6.56

9.60

Table 4 Deformation moduli of protection layer structures Protection layer structures

Deformation modulus, MPa Test results

Required

After soaking in water for 24 h

28 days

Crushed stone ballast (40 cm) Crushed stone, gravel and sand mix (25 cm) Bottom layer—sand (10 cm)

160

150–200

–

–

Crushed stone ballast (40 cm) FGA (25 cm) Bottom layer—sand (10 cm)

160

No more than 650

160

150

Crushed stone ballast (40 cm) XPS panels (4 cm) Bottom layer—sand (10 cm)

23.8

13–33.5

24.0

21.8

C x (Re)—particle drag force against water flow (Re—Reynolds number), for water flow C x (Re) = 1.4–1.6, S—cross-section area of ballast particle of used size, ρ—water density kg/m3 . It is needed to use ballast from produced hard rocks to construct a protection layer, which will be stable and tolerant to water erosion. Its particles with sharp facets will provide sufficient cohesion and static coefficient of friction. If protection layer is constructed of light particles (i.e., FGA), stability and erosion tolerance is achieved with increasing of ballast particles cohesive force F c . The standard design may include installation of geotextile at the top and bottom of protection layer. Geocells of 7.5–10 cm high may be placed over the lower layer of geotextile and filled with ballast of 20–40 cm grain size. At the top 3–4 cm of ballast is placed and processed with polymer binder.

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4 Conclusion Test study of frost protection layer structures was performed on Russian Railway Research Institute experimental track in Moscow. Cellular materials used for protection layers were FGA ballast and XPS panels. Obtained results show that FGA ballast can be used in protective layer. It is suitable for installing on wetted and less stiff subgrade sections (with a deformation modulus less than 50 MPa). Installation of geotextile at the top and bottom of protection layer is advised to achieve required stability and water erosion tolerance.

References 1. Kuznetsova E, Hoff I, Danielsen SW (2016) FROST—frost protection of roads and railways. Mineralproduksjon 7:B1–B8 2. Oiseth E, Aabøe R, Hoff I (2006) Field test comparing frost insulation materials in road construction. In: Conference proceedings http://www.vegvesen.no/_attachment/110441/binary/192536 3. National Standard GOST 25100-2011 (2011) Soils Classification. Russia, Moscow 4. Arulrajah A, Disfani MM, Maghoolpilehrood F, Horpibulsuk S, Udonchai A, Imteaz M, Du YJ (2015) Engineering and environmental properties of foamed recycled glass as a lightweight engineering material. J Clean Prod 94:369–375 5. Auvinen T, Pekkala J, Forsman J (2013) Covering the higway E12 in the centre of Ämeenlinna— Innovative use of foamed glass as light weight material of approach embankment. In: XXVIII International Baltic Road Conference. Vilnius, Lithuania 6. Frydenlund TE, Aabøe R (2002) Use of waste materials for lightweight fills. In: International Workshop on Lightweight Geomaterials. Tokyo, Japan 7. Frydenlund E, Aabøe R (2003) Foamglass—a new vision in road construction. In: Proceedings of the 22nd PIARC—C12 technical committee on earthworks, drainage and subgrade. Durban, South Africa 8. Øiseth E, Refsdal G (2006) Lightweight aggregates as frost insulation in roads—design chart. In: Proceedings cold regions engineering—current practices in cold region engineering. Orono, USA 9. Segui P, Doré G., Bilodeau J-P, Morasse S (2015) Innovative materials for road insulation in cold climates: foam glass aggregates. Innov Geotech Mater Eng

Design, Construction and Exploitation of Geotechnical Structures

Intensive Technology of Construction of Geotechnical Structures in Transport Taisiya V. Shepitko, Svyatoslav Ya. Lutsky, Vyacheslav A. Zabolotny and Igor A. Artyushenko

Abstract The scientific basis for the intensive technology of increasing the foundation and geotechnical structures stability on the massive layers of weak soils is outlined. The authors have this technology patented. It is intended for the construction of railways and highways in swampy and waterlogged areas. The stages and principles of intensive technology are described. The content and order of strengthening the weak base are considered. The effectiveness of the technological regulations application for strengthening the weak formation basis on the M-11 Moscow—St. Petersburg Highway is determined and the experience of this application is summarized. Intensive technology for strengthening the weak bases is implemented in conjunction with geotechnical research methods. The necessity of technological management of the construction machines operation modes in order to improve the strength characteristics of soils is shown. The solution is made using the finite element method (FEM). Technological management methods have been developed for maximum allowable loads. The conclusions presented in this article were made using the results of the weak basis hardening processes experimental study which took place in the experimental areas of geotechnical construction. Keywords Geotechnical structures · Weak soils · Construction · Technological control

1 Introduction Intensive technology has been developed, patented and implemented on the transport construction sites [9, 13] to ensure the reliability of weak bases and the compliance of geotechnical structures with the requirements of technical regulations and standards [1, 15, 17] at all stages of the life cycle. The fundamental academic writings T. V. Shepitko (B) · S. Ya. Lutsky · I. A. Artyushenko Russian University of Transport (MIIT), Moscow 127994, Russia e-mail: [email protected] V. A. Zabolotny LLC “Transstroymekhanization”, Moscow 119048, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_44

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and constructive-technological solutions [5, 14] are focused mainly (even at the construction stage) on the final structure, its design parameters and soil characteristics. The problem is that these characteristics start to change in the preparation period, as soon as the builders step into the right-of-way. Intensive technology (IT) is based on three interrelated principles: (1) applying the maximum allowable load; (2) management of technological processes; (3) monitoring of structure and environment stress–strain state in real-time. In this paper, the content and order of weak base hardening are considered using the example of roadbed sections construction on M11 Moscow—St. Petersburg Highway completed by machinery park of LLC “Transstroymekhanization” (TSM) [8, 10]. Those sections are located in the swampy areas. The management of technological processes is based on the gradual building and permanent monitoring of the system “weak soils—sand replacement massif, drilling and blasting technology—shock-pulse technology—vibration compaction of the upper zone” condition (Table 1). The alphabetical symbols: W —humidity, ρ—density, C—adhesion, ϕ—internal friction angle, E—modulus of soil deformation; e, Kd, Ky, Kst—coefficient of porosity, dynamic coefficient, coefficient of compaction and coefficient of stability of the base, respectively; Hc, L, Q—depth, distance between the bore holes, weight of the explosive, respectively; Pmt, Pkt, Pt—maximum allowable process load: from shock-pulse machines, from the roller and the load increase at the moment t, respectively; Sn, Sk—initial and final settlement; A, v—amplitude and frequency of the vibrator; Pp—pore pressure; Ut—degree of consolidation; Ld—the distance between the positions of the shock-pulse machine. Table 1 The intensive technology of massive layers of weak soils at the base of the roadbed strengthening stages 1. Purpose

2. Characteristics and parameters

3. Condition evaluation

Stage 1. Diagnosis

1.1 Base stability Evaluation and forecast

2.1 Characteristics of weak soils ρ, W, ϕ, C, e

3.1 Initial parameters: Kst, Sn

Stage 2. Replacement of the weak layer, drilling and blasting technology

1.2 Creation and landing of the sand massif on the bottom

2.2 Parameters of drilling and blasting technology: Hc, L, Q

3.2 Static sounding ρ, E, Pp

Stage 3. Shock-pulse compaction

1.3 Strengthening the sand massif

2.3 Load and parameters of the shock-pulse machine: Pmt, Kd, Ld

3.3 Geophysical research μt, Kyt, Ut

Stage 4. Vibrating compaction of the upper zone

1.4 Design density of the upper base zone

2.4 Load and parameters of a vibrating road-roller: Pkt, (A, v), Pt

3.4 Hydrogeological survey Wt, Kst, Sk

Intensive Technology of Construction of Geotechnical Structures …

423

The applied technology which consists in removal (squeezing) of peat and its replacement by sandy soil with landing on the mineral bottom by mechanical, hydromechanical and drilling and blasting methods [16] does not guarantee the stability of the base due to boundary conditions change and layer structure heterogeneity. There is a probability of residual deformations: (1) in the boundary layer between the mineral bottom and backfill; (2) in a loose sand massive during the compaction; (3) in the whole compacted base due to soil characteristics changes caused by changes in humidity and dynamic effects during the construction, especially for the unmanaged processes. For the massive weak base the piles with a grillage, including gravel and sand piles in a geotextile shell is used [2, 12]. This solution should provide an increase in the load capacity and a decrease in base settlement because the piles are expected to take some part of operational load normal stresses and transfer it to the mineral bottom. But even for this solution, it is necessary to check the stability of the weak space between the piles, taking into account the continuous changes in soil characteristics.

2 Analysis, Methodology, and Implementation For a directed increase in the degree of consolidation of a weak base the soils characteristics changes diagnostics is necessary. The diagnostics should be done while performing technological processes in real-time and taking into account pore pressure. To this end, IT strengthening of weak bases was carried out in conjunction with geotechnical research methods [6, 7] at the construction site of M11 highway next to Bologoye. The task was to control the progress of the gradual stabilization of the base: (1) after replacing weak soils with a sand massif using drilling and blasting methods; (2) after compaction of the sand massif using heavy machines of shock-pulse compaction and vibrating rollers. In accordance with the technical assignment of TSM LLC, a set of geotechnical methods for surveying the foundation of the M11 roadbed, made by Inzhgeofizika Research and Production Enterprise, included: – electrical survey by method of resistance in the geoelectric tomography modification; – seismic reflection using the method of refracted waves and data processing using seismic tomography; – hydrogeological survey. For hydrogeological survey, six bore holes were constructed with hydrostatic pressure sensors installed in various lithological rock varieties: a sand massif of embankment, weak clays and peats, loams and sandy loams. As a result of pore pressure monitoring after blasting operations, a downward trend in the static water level has been determined which indicates the process of excess pore pressure consolidation and dispersion in clay soils. At the same time, on certain

424

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sections of the M11 highway after the completion of drilling and blasting operations, dangerous phenomena were detected: the embankment settlement occurring as a result of movements connected with the bog bottom topography and the possible extrusion of “weak” fluidized clay soil. To confirm the assumption that the development of the embankment settlement relates to the movement of the embankment massif in the transverse and longitudinal directions along the bog bottom topography inclinometers were installed and inclinometric measurements were made. In such areas additional precisely focused explosions were performed to release compressed water (Fig. 1). The geophysical studies results analysis consisted in evaluation the degree of soil compaction by the base stabilization technology using explosion energy after CES Ohm*

Geoelectric section along profile 1, stage 1

(a)

Пк 3566+85

Пк 3567+30

Пк 3567+93

Пк 3568+35

180

H абс, м Пк 3568+50

Пк 3568+70

H абс, м

180

170

170

160

160

150

150 140

140 0

20

40

60

80

100 120 140 160 180 200 220 240

distance between observation points, m (b)

Fig. 1 a Geoelectrical cross-section, built on the results of geophysical works on the site of M11 highway; b Settlement, pore pressure reduction and release of squeezed water on the site of M11 highway after drilling and blasting

Intensive Technology of Construction of Geotechnical Structures …

425

the second IT stage (Table 1) based on changes in physical parameters—electrical resistance and elastic waves propagation speeds. Geoelectrical sections obtained using the electrical survey results characterize the distribution of electrical resistance (CES) in depth. Weak and liquid soils, generally, have a resistance of up to 50–60  * m, water-bearing sands and sands—up to 120– 150  * m, dry and slightly moist sands from 150–200  * m and above. Weak soils are also characterized by low propagation speeds of elastic waves. According to the geoelectrical cross-section (Fig. 1) and data from the bore holes with pore pressure sensors a low-resistance zone of water-bearing soils with high pore pressure was determined. The directed planning and execution of the second stage of drilling and blasting operations showed that the danger zone changed both the size and the configuration, which indicates that the water was redistributed in the cross-section. The low-resistance zone has significantly reduced. When comparing the results of electro-tomography at the first and second stages, it was concluded that there are significant changes in the resistance distribution by depth in the crosssection. In the middle and lower parts of the cross-section, from the level of 165 m to the level of 140 m, there is a significant increase in electrical resistance both throughout the whole section and at local levels. In general, the resistance of the cross-section increased, which indicates a reduction of weak and flowing soils. The third stage “Compaction of the trench backfill loose sand layer after replacing the soil mass” consists in developing technological regimes and reasoning of the parameters of intensive compaction of the loose sands layer with maximum allowable loads after replacing weak soils. The parameters and duration of the loads should be adjusted depending on the stability of weak soils. On the construction of the M11 highway, these works were carried out by TSM LLC using the Terra-mix shock and pulse compaction machine (SPM). During the process of its adaptation to the construction conditions, parameters and adjustable modes that affect the deformation and compaction (porosity) of soils of a weak base were determined. These include: location of machine positions Ld, diameter D and punch weight q, Im is the impact impulse, the dynamic factor Kd, the number of hits from each position N. Technological regulation consisted in choosing the parameters of the dynamic (shock) impact for and between the positions of the machine’s operation SPM. In accordance with the theory of shock-pulse interaction of a punch with a soil surface (prof. N. Ya. Kharkhuta) [3], the choice of parameters for shock compaction is proposed to be determined by the specific impulse per unit contact surface and the dynamic factor Kd, which allows to use the quasi-static load instead of dynamic impact in calculations. To determine the soils of the compacted zone characteristics an axially symmetric problem is solved in a mixed elastic-plastic formulation [10]. The solution is made using the finite element method (FEM). On the basis of stress-strain state numerical modeling, the deformations of the soil massif when it interacts with the hit punch are determined, as well as the change in the soil porosity. Calculations are made for three values of the punch diameter: 0.8, 1.5, and 2.0 m and for three values of the initial medium size sands density.

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The progress of the work performed is fixed by the SPM machine onboard computer in the form of a plan, on which each compaction location is plotted with GPS coordinates, and a report in which the number of compaction points, the exact position of the machine using GPS navigation, the date of work, the number of pulses, the value of the last settlement in cm, the total settlement of a given compaction point on this date and the total settlement of a given compaction point are indicated (Fig. 2). The study of the interaction of a shock-pulse machine with a sandy mass has shown: 1. The technological mode of the shock-pulse machine leads to the formation of a compacted area and the consequent growth of contact stresses, density, and dynamic coefficient. Its length (depth) increases, respectively due to the weight of soil attached to the bottom, and the porosity decreases (with slowing down). Managing of the technological regime should consist in establishing loads close to the ultimate strength of compacted sands [6];

IMPULSECOMPACTION DATA Moskau-st.Petersburg Customer: Transstroymechanisazia Realization from: 14.11.2013 Realization to: 15.01.2014

Project-Nr.: 130672 Name:

POINT-ID POINTDESCRIPT. X Y DATE BLOWS FIN.SET DEEP DEEPTOTAL STCO PASS LAYER 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3

4 5 6 7 8 9 10

10 20 30 40 50 60 70 80

360000015 7772912,98 8597406,95 20.11.2013 21 6 199 199 S 1 IV_Flaeche 31 16 12 11 11 11 8 8 8 9 8 7 8 7 6 7 7 6 6 6 6 360000016 7772910,31 8597405,58 20.11.2013 26 6 248 248 S 1 IV_Flaeche 37 18 13 12 12 9 9 10 8 8 8 8 7 8 8 7 7 7 7 6 6 6 7 6 6 6 360000023 7772908,99 8597401,54 19.11.2013 16 4 131 131 S 1 IV_Flaeche 22 11 10 9 8 8 7 7 7 6 7 6 7 6 6 4 360000024 7772906,32 8597400,17 19.11.2013 8 6 75 75 S 1 IV_Flaeche 22 11 9 8 8 6 5 6 360000025 7772914,33 8597404,27 20.11.2013 19 6 178 178 S 1 IV_Flaeche 33 15 12 11 10 9 9 8 7 8 7 7 6 6 6 6 7 6 6 360000026 7772911,66 8597402,9 20.11.2013 26 6 243 243 S 1 IV_Flaeche 30 17 13 12 11 10 10 10 9 9 9 8 8 8 7 7 8 7 6 7 6 6 7 6 6 6 360000027 7772906,25 8597406,87 19.11.2013 14 5 127 127 S 1 IV_Flaeche 25 13 11 12 9 7 7 7 7 6 7 6 6 5 360000028 7772903,58 8597405,5 19.11.2013 10 4 84 84 S 1 IV_Flaeche 19 12 8 8 6 6 7 6 6 4 360000029 7772911,59 8597409,61 20.11.2013 26 5 216 216 S 1 IV_Flaeche 30 15 11 10 10 9 8 8 7 8 7 7 6 8 7 6 7 6 6 6 6 7 6 5 5 5 360000030 7772908,92 8597408,24 20.11.2013 23 5 208 208 S 1 IV_Flaeche 30 16 12 10 9 10 8 9 8 8 8 9 8 7 8 6 7 6 6 7 6 5 5 360000037 7772907,64 8597404,21 19.11.2013 16 5 179 179 S 1 IV_Flaeche 49 20 12 11 10 8 8 8 8 8 7 6 6 5 6 5 360000038 7772904,97 8597402,84 19.11.2013 14 5 116 116 S 1 IV_Flaeche 28 10 6 8 8 7 7 6 6 6 6 7 5 5 360000045 7772913,09 8597393,52 19.11.2013 17 6 150 150 S 1 IV_Flaeche 32 12 10 10 8 8 7 7 7 6 6 6 6 7 5 6 6 360000046 7772910,42 8597392,15 19.11.2013 8 6 79 79 S 1 IV_Flaeche 28 11 8 7 7 5 6 6 360000051 7772917,85 8597387,52 19.11.2013 14 5 127 127 S 1 IV_Flaeche 24 14 10 10 9 8 8 7 8 6 6 7 5 5 360000052 7772915,17 8597386,17 19.11.2013 10 6 97 97 S 1 IV_Flaeche 26 14 8 8 8 9 7 6 6 6 360000054 7772920,53 8597388,88 20.11.2013 21 6 203 203 S 1 IV_Flaeche 34 18 13 12 10 9 10 9 9 8 8 7 8 8 6 6 6 6 6 6 6 360000055 7772918,43 8597396,26 20.11.2013 24 5 215 215 S 1 IV_Flaeche 34 15 13 10 10 9 8 9 8 7 7 8 8 7 6 7 6 6 6 7 6 6 6 5 360000056 7772915,76 8597394,89 20.11.2013 26 6 238 238 S 1 IV_Flaeche 31 16 14 12 12 10 11 9 8 8 8 8 7 7 7 6 7 7 6 7 6 7 6 6 6 6 360000057 7772912,5 8597384,81 19.11.2013 7 5 66 66 S 1 IV_Flaeche 23 10 8 7 6 6 5 360000059 7772915,71 8597401,61 20.11.2013 19 5 168 168 S 1 IV_Flaeche 26 13 11 11 9 9 7 8 8 7 7 7 6 7 7 6 6 6 5 360000060 7772913,04 8597400,24 20.11.2013 19 6 175 175 S 1 IV_Flaeche 25 16 13 11 11 9 9 8 8 7 8 8 6 6 7 6 6 6 6 360000065 7772910,37 8597398,87 19.11.2013 13 6 120 120 S 1 IV_Flaeche 24 14 11 10 8 8 7 8 6 7 5 6 6 360000066 7772907,7 8597397,5 19.11.2013 9 5 80 80 S 1 IV_Flaeche 20 13 9 8 7 6 7 5 5 360000067 7772911,72 8597396,19 19.11.2013 18 5 161 161 S 1 IV_Flaeche 30 12 12 10 8 8 8 7 7 8 6 7 7 8 6 8 5 5 360000068 7772909,05 8597394,83 19.11.2013 11 7 95 95 S 1 IV_Flaeche 22 11 9 8 7 6 6 8 6 5 7 360000069 7772917,06 8597398,93 20.11.2013 18 5 173 173 S 1 IV_Flaeche 33 15 12 10 10 10 8 7 9 8 8 7 7 6 6 6 6 5 360000070 7772914,39 8597397,56 20.11.2013 17 6 172 172 S 1 IV_Flaeche 33 18 15 12 10 10 8 8 8 7 7 7 7 6 6 6 6 360000077 7772909,77 8597390,15 19.11.2013 11 5 94 94 S 1 IV_Flaeche 23 11 9 7 7 7 7 6 7 5 5

Fig. 2 The report of the SPM machine onboard computer on the settlement and the number of impulses N at each position during the compaction of the road formation\base (fragment)

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2. Along with the formation of compacted area, there are horizontal stresses (decreasing while the distance from the contact increases) caused by the lateral expansion of the ground and compact the zone between shock-pulse positions. Managing consists of determining the distance between the SPM machine positions at which the maximum possible compaction occurs; 3. The process of compaction is characterized by heterogeneity—the soil resistance against the deformations in direction of the vertical load is higher than the one in horizontal direction. The results of FEM calculations regarding the formation of a compacted area of a sand massif are consistent with the fundamental writings on soil mechanics [18] and soil compaction mechanics [3]. At the same time, the pulse-impulse method does not ensure the design density and stability of weak soil in the upper active zone of the base. The structural diagram (see Table 1) provides vibrating compaction of the upper layer with a dense grillage construction, which distributes the load and makes it possible to equalize the stresses between the shock positions of the machine to the standard density value. To form the compacted upper zone, the fourth IT stage is proposed—an intensive mode of vibrating rollers equipped with an automated density control system (VR). The technological requirement is to determine and maintain the maximum allowable (in terms of safety factor) load from the roller [2]. The dynamic load from a vibratory roller in a sandy massif should not exceed the safe limit:   Pkt (At , Vt , υt ) ≤ min Ppr , Pb, Pts t

(1)

where Pkt —load, depending on weight, velocity V t , amplitude At , frequency υ of the vibrating roller and contact stiffness of the compacted layer in the t period of intensive technology; Ppr —ultimate strength of the sand layer, taking into account the dynamic factor Kd; Pb—safe load for the upper layer of the sand shear; Pts — maximum thixotropy vibration load. Values Ppr , Pb and Pts depend on the depth of the layer and the strength characteristics of the soil, which vary in each layer of the base during the technological cycle. The technological mode of compaction of the upper unstable base layer by a vibrating roller requires two checks: (1) The load from the weight of the vibromodule and the driving force of the roller should not exceed the maximum allowable load. Managing parameters when choosing a vibrating roller are its weight, mode (static at first passes, shock pulse with high or low amplitude, oscillation); (2) The magnitude of the acceleration of oscillations during the operation of a vibrating roller (starting from a low amplitude) propagating in the ground should not exceed the critical acceleration [3]. Monitoring of the subgrade base condition at the fourth stage of the shock impulse compaction also included a geotechnical survey of complex sections of the road formation using seismic tomography. The transition from the parameters of wave processes (longitudinal and transverse waves propagation velocity) to the characteristics of a compacted massif was completed according to the method [16, 19] based on the

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building of cross-sections with a field of Poisson ratio μ change. For technological control, such a transition is useful because of the following reasons: 1. The Poisson ratio is expressed in terms of longitudinal and transverse waves velocities in the seismic tomography of the soil massif, that depend on humidity, density, pore pressure and change during compaction. The stability changes, respectively, so it is necessary to diagnose its condition in real-time and to manage the technological load; 2. The value of the Poisson ratio is correlated with the characteristics of the soil stress-strain state [5]: G = E/2(μ + 1), where E, G—deformation modulus and shear modulus of the soil. The lithological composition, porosity, and humidity have the defining influence on the velocity values of elastic waves in soils. After the vibrating compaction of the upper zone of base at the fourth IT stage, elastic waves velocities in the crosssection increased, which was reflected in the results of seismic survey. A change in the Poisson ratio and an increase in the filtering ratio of soils has shown that they were compacted according to a drained pattern, accompanied by the release of water from the pores of the soil with a simultaneous increase in shear modulus and the transfer of clay soils of the lower layer to a state with a higher filtration coefficient. The final compliance of the road formation base with the design requirements was confirmed by the results of static sounding.

3 Discussion The interrelation of technological strengthening processes in all zones of the base makes it necessary to clarify the rules [15] for calculating the effective shear stresses τ, namely, to take into account the changes in technological loads dynamics at the moment t: τt = (σt − Ppt ) tgϕt + Ct ,

(2)

where σt, Ppt —the value of the total normal stress and pore pressure in the boundary layer; C t , ϕt—strength characteristics of soils of the boundary layer at the moment t. To forecast changes in parameters dynamics during IT, impulse compression onboard computer data processing is necessary (see Fig. 2). Statistical analysis in the program Statistika, 3D (235 data points, with good agreement R2 = 0.938) allowed to determine general regressive correlations of current settlement S (Y ) when changing the number of hit (x) in the shock pulse machine position from first to last: (1) Y = 32.736x−0.449 ; R 2 = 0.9259; correlation taken in the range of impacts 1–24;

(3)

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(2) Y = 24.262x−0.477 ; R 2 = 0.9129;

429

(4)

correlation taken in the range of impacts 21–46. Regressive correlations show the rate of decrease in current settlement when the hit number changes. They are intended for the forecast calculation of the required number of hits to obtain the design settlement Sk and for planning of the operation schedule for the SPM machine on the construction site. The conclusions made as a result of an experimental study of the weak bases strengthening processes in the experimental areas of geotechnical construction are listed below.

4 Conclusions • The concept of intensive technology consists in the organization of diagnostics, strengthening and consolidation of massive layers of weak soils in three different areas with different properties (upper protection zone, replacement sand massif, weak boundary layer). The managing of technological processes is based on the formation and monitoring in real-time of the technologically safe system with adaptive blocks “weak soils—sand replacement massif, drilling and blasting technology—shock-pulse technology—vibration compaction of the upper zone”. • Two methods for the technological managing of the maximum allowable load have been developed: (a) by the strength limits of the soil and critical acceleration in the active zone of shock-pulse compaction machines and vibrating rollers operation; (b) by the safe load, taking into account the weight of the sand massif, the dynamic effects of machines and pore pressure in the lower boundary layer. • The results of geophysical studies have confirmed a consistent increase in stability and consolidation of the base in stages of intensive technology. According to the results of electrical exploration, changes in the soils resistance distribution were revealed. In general, there is an increase in resistance values, which indicates an increase in the degree of compaction and a decrease in soil humidity, as well as a reduction of weak and liquid soils areas at the base of the embankment. • To protect against thixotropy during the process of the sand massif upper zone compaction, it was proposed to manage the magnitude of the vibrations acceleration from the vibratory roller by: (a) changing the frequency and amplitude (starting from the static mode with the vibrator off); (b) adjusting the parameters of the roller during the final passes, completing with the oscillation mode.

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References 1. DIN EN 1997-1-2014 (2014) Eurocode 7. Geotechnical design. Part 1. General rules 2. Kempfert HG, Stadel M, Zaeske D (1997) Berechnung von geokunststoffbewehrten Tragschichten über Pfahlelementen. Bautechnik 74(12):53–61 3. Kharkhuta NY, Vasilyev YM (1975) Strength, stability and compaction of the subgrade soil roadways. Transport, Moscow 4. Konshin G (2007) Diagnostics of the road bed of railways. GOU UMTs, Moscow 5. Kramarenko VV (2017) Soil science. Studme, Moscow 6. Liu J, Peng L (2009) Experimental study on the unconfined compression of a thawing soil. Cold Reg Sci Technol 58:92–96 7. Lutsky SY (2005) Recommendations for intensive technology and monitoring the construction of earthworks on weak grounds. TIMR, Moscow 8. Lutsky SY, Sakun AB (2015) Intensive technology of hardening weak foundations of the road bed. Transp Constr 8:20–24 9. Lutsky SY, Shepitko TV (2009) Construction of communication lines in the North. LATMES, Moscow 10. Lutskiy SY, Shepitko TV, Shepitko ES (2017) Geotechnical structures foundation stabilization technological processes control. In: Proceeding of 2016 ieee conference on quality management, transport and information security, information technologies. Sankt-Petersburg, pp 398–400 11. Pescatore M, Roma V (2005) Environmental impact caused by high speed train vibrations. Proc Int Geotech Conf 1:407–414 12. Raithel M (2006) Geotextile-encased columns (GEC) for foundation of a Dyke on very soft soils. In: Proceedings 7th international conference on geosynthetics. Nizza, pp 1025–1028 13. Lutsky SY, Ashpiz ES, Dolgov DV (2005) Roadbed and method of its construction: US Pat. 2273687 Ros. Federation. No. 2005104907103 (006247) 14. Shakhunyants GM (1987) Railway track. Transport, Moscow 15. SP 22.13330. Foundations and foundations (2016) 16. SP 45.13330.2017 (2017) Earthworks, foundations and foundations 17. Technical regulations on the safety of buildings and structures: Federal Law of the Russian Federation of December 23, No. 384-FL (2009) 18. Tsytovich NA (1983) Soil mechanics. Higher School, Moscow 19. Voznesensky EA, Kovalenko VG (2005) Dilution of soils under cyclic loads. MGU Publishing House, Moscow

Slope Failure Status and Analytical Results of Slope Stability from Fracture Orientations. Case Study in 3B Highway in Xuathoa Area, Backan Province, Vietnam Truong Thanh Phi Abstract This paper presents the slope failure status and analytical results of slope stability by using rock slope engineering of Hoek and Bray (Rock slope engineering. Taylor & Francis Group, London and New York, p 431, [3] along the 3B highway in Xuathoa area, Backan province, Vietnam. The analytical results from 3813 fracture measurements from 33 survey sites have shown that the plane failure, wedge failure and toppling failure can occur on the rock slope surface at most survey locations along the road. Especially, the plane failure phenomenon can occur with the largest percentages: 35.0%, 41.0%, 36.0%, 41.8%, 45.7% belong to the sections in the directions of E–W, N–S and NW–SE at the survey locations: BK-27, BK-30, BK41, BK-59 and BK-72; the wedge failure phenomenon can occur with the largest percentages: 49.6%, 40.7%, 62.1%, 53.9%, 38.5%, 41.7%, 40.0%, 39.9%, 36.7% belong to the sections in the directions of E–W, N–S and NW–SE at the survey locations: BK-52, BK-53, BK-57, BK-63, BK-66, BK-68, BK-72, BK-75 and BK80; the toppling failure phenomenon can occur with the largest percentages: 10.9%, 12.7%, 11.6%, 13.7% belong to the sections in the directions of the NW–SE and N–S at the survey locations: BK-79, BK-80, BK-81 and BK-83. Keywords Plane failure · Wedge failure · Toppling failure

1 Introduction The slope failure occurs quite commonly along roads in the mountainous provinces of Vietnam. Their occurrence not only affects the economic activities but also threatens the lives of people, impact negatively on the environment. The slope failure along the road is one of the most important problems that the localities in the mountainous provinces of Vietnam are facing. The slope stability researches in Vietnam have been conducted since the early 2000s and it is concentrated mainly at the Institute of Geology-Vietnam Academy of T. T. Phi (B) Hanoi University of Natural Resources and Environment, Hanoi, Vietnam e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_45

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Science and Technology; Vietnam Institute of Geosciences and Mineral Resources; Institute of Transport Science and Technology. However, almost studies were conducted on the basis of processing satellite image data, terrain and geomorphology to build the zonation map and forecast risk of landslide. Truong et al. [8] used the remote sensing image data of Landsat satellite 5 through ArcGIS 9.3 software applications to build the landslide risk map for predicting in Danang City. Nguyen et al. [5] have integrated a hierarchical model (AHP) in GIS to establish a landslide risk map in Quang Tri province. Tran et al. [7] used the statistical modeling analysis method with the help of GIS software with the parameter overlap of slope, aspect, lithology, geomorphology, precipitation… to build the zonation map of landslide potential to support for sustainable urban development planning, as well as to provide measures to prevent landslides for Backan city. Recently, Bui et al. [1] used GeoStudio software with SLOPE/W module to audit the slope stability. The study results are the basis to propose the slope stability design. Recently, the other authors of Vietnam have developed the Block Theory of Goodman and Shi [2] to analyze slope stability based on fracture orientation and slope surface direction [6]. In this paper, the author presents the field survey data and analytical results of slope stability along the 3B highway in Xuathoa area, Backan province, Vietnam by using Hoek and Bray’s application [3] to support for design and tunnel construction in the future.

2 Materials and Method 2.1 Materials Topographic map of scale 1:10.000; Geological map of scale 1:200.000. The geological investigation of rock slope stability was carried out at 84 sites on the rock slope surface along 3B highway in Xuathoa area, Backan province, Vietnam. In which, 33 sites measured 3813 fracture orientations. The data collection is carried out randomly by using compass with all fractures at each survey site. The map of survey sites in study area is shown in Fig. 1. Where: D2–3 th: Tam Hoa formation: polymictic conglomerate, gritstone, limestone shale; D1 ml 2 : Mia Le formation: clayish siltstone, limestone shale; D1–2 nq1 : Na Quan formation: Limestone shale; D1–2 nq2 : Na Quan formation: Shale interbedded with limestone.

2.2 Application for Slope Failure Analyses The analyses of plane failure, wedge failure, toppling failure and circular failure were carried out by Hoek and Bray [3], based on the fracture orientation. The analytical

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Fig. 1 Geological map, minimized from scale 1:200.000 and survey locations [4]

results will indicate the types of plane failure, wedge failure, toppling failure and circular failure on the rock slope surface and shown in Figs 2 and 3.

Fig. 2 a Plane failure, b wedge failure, c circular failure and d toppling failure (according to Hoek and Bray [3]

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Fig. 3 a Plane failure, b wedge failure and c toppling failure (according to Hoek and Bray [3]

3 Slope Failure Status Along 3B Highway 3.1 Landslide on Weathered Layer Along the 3B highway in Xuathoa area, Backan province, Vietnam, the component of rocks included limestone clay, shale and siltstone. The thickness of weathered layers varies from 40 cm to 6 m at different survey sites, covering the bedrock and in the fracture zones. The field survey results showed that almost weathered layers of the clayish siltstone are land sided (BK-03, BK-04, BK-09, BK-11, BK-13, BK-37, BK-44, BK-45, BK-45, BK-44, BK-45). The typical landslide points are shown in Fig. 4.

(a)

(b)

Fig. 4 a The landslide point on the weathered layer with the size of 14 m wide, 30 m high at the field survey location BK-43; b the landslide point on the weathered layer with the size of 7 m wide and 20 m high, which is controlled by two fracture systems 005/70 and 150/80 at the survey location BK-49

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3.2 Slope Failure on Fractured Surfaces The 3B highway in Xuathoa area, Backan province, Vietnam cut through the ancient rocks of the Devonian system which are mainly limestone shale, intercalation among them are weathered layers. These rocks are heavily broken formed many fracture systems with different orientations, occurred the plane failure at the survey sites: BK-07, BK-08, BK-10, BK-15, BK-19, BK-28, BK-35, BK-34, BK-35, BK- 62, BK-65, BK-67, BK-68, BK-73, BK-76, BK-78, BK-79, BK-80, BK-82; the wedge failure at the survey sites: BK-16, BK-25, BK-29, BK-30, BK-31, BK-36, BK42, BK- 62, BK-68, BK-73, BK-74, BK-77, BK-80, BK-81; the toppling failure at the survey sites: BK-59, BK-78, BK-82. The typical slope failure photos and the analytical results are shown in Fig. 5.

(a)

(b)

Fig. 5 a Wedge failure of conjugate fractures with the orientations 320/45 and 040/45 on the slope surface of strike 010/75 at the survey site BK-65; b plane failure of fracture orientation 070/35 on the slope surface of strike 060/80 at the survey site BK-67

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4 Analytical Results The analyses of the slope stability on the rock slope surfaces along 3B highway in Xuathoa area, Backan province, Vietnam is carried out at each survey site according to Hoek and Bray’s application [3] with the input parameters as the fracture orientation, the rock slope surface direction and friction angle. In this case, the friction angle for the limestone shale is determined to be 25°. The analyses and statistics of slope stability are carried out at each survey location, shown in Figs. 6 and 7. The statistical results of failure potential blocks of the plane failure, wedge failure and toppling failure in Figs. 6a and 7a, b are recorded in Table 1. The analytical results of percentage of plane failure, wedge failure and toppling failure in Table 1 are plotted in Fig. 8.

(a)

(b)

Fig. 6 a Map of fracture orientation contour at each survey location; b map of survey sites can occur the plane failure according to analyzing the fracture orientations by Hoek and Bray’s application [3]

Fig. 7 a Map of survey sites can occur the wedge failure; b map of survey sites can occur the toppling failure according to analyzing the fracture orientations by Hoek and Bray’s application [3]

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Table 1 Statistical results of the number and percentage of the fractures can cause slope failure at the survey sites along the 3B highway in Xuathoa, Backan province, Vietnam No.

Survey locations

Number

Percentage (%)

No

Survey locations

Number

Percentage (%)

1

BK-01

13

17.81

18

BK-61

7

4.24

2

BK-15

5

3.94

19

BK-62

6

7.89

3

BK-17

4

3.88

20

BK-63

3

4.62

4

BK-21

0

0.00

21

BK-66

0

0.00

5

BK-26

1

0.86

22

BK-68

10

8.33

6

BK-27

3

2.46

23

BK-69

6

5.83

7

BK-28

5

5.21

24

BK-72

2

2.86

8

BK-30

4

2.92

25

BK-74

4

3.36

9

BK-34

9

9.38

26

BK-75

10

10.10

10

BK-35

7

6.67

27

BK-76

12

9.38

11

BK-41

2

1.06

28

BK-78

09

5.92

12

BK-50

10

7.35

29

BK-79

17

10.97

13

BK-52

1

0.88

30

BK-80

20

12.66

14

BK-53

7

5.19

31

BK-81

20

11.63

15

BK-57

1

1.41

32

BK-82

21

9.77

16

BK-58

7

7.78

33

BK-83

14

13.73

17

BK-59

5

6.33

Fig. 8 Graph of fracture percentage can occur the plane failure, wedge failure and toppling failure at each survey site along the 3B highway in Xuathoa, Backan province, Vietnam

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The slope failure analyses are conducted on the basic of the statistical percentage of fracture orientations which can occur the plane failure, wedge failure and toppling failure at each survey site along the 3B highway in Xuathoa, Backan province, Vietnam. In Fig. 8, the fracture percentage lies within the region that can occur the plane failure, varies slightly among the survey sites. The largest percentage values are 35.0%, 41.0%, 36.0%, 41.8%, 45.7% belong to the survey sites: BK-27, BK-30, BK-41, BK-59 and BK-72, in the directions of E–W, N–S and NW–SE; similarly, for the wedge failure, the largest percentage values are 49.6%, 40.7%, 62.1%, 53.9%, 38.5%, 41.7%, 40.0%, 39.9%, 36.7% belong to survey sites: BK-52, BK-53, BK57, BK-63, BK-66, BK-68, BK-72, BK-75, BK-80 in the directions of E–W, N–S and NW–SE; for the toppling failure, largest percentage values are 10.9%, 12.7%, 11.6%, 13.7% belong to the survey sites: BK-79, BK-80, BK-81 and BK-83, in the directions of the NW–SE and N–S.

5 Conclusions The field survey results along the 3B highway in Xuathoa area, Backan province, Vietnam have identified that most weathered layers occur landslide on the slope surfaces. The analytical results of 3813 fracture orientations at 33 survey sites on the limestone shale of Devonian system have indicated that plane failure, wedge failure and toppling failure can occur at almost survey sites. The plane failure phenomenon can occur with the largest percentages: 35.0%, 41.0%, 36.0%, 41.8%, 45.7% belong to the sections in the directions of E–W, N–S and NW–SE at the survey sites: BK-27, BK-30, BK-41, BK-59 and BK-72; the wedge failure phenomenon can occur with the largest percentages: 49.6%, 40.7%, 62.1%, 53.9%, 38.5%, 41.7%, 40.0%, 39.9%, 36.7% belong to the sections in the directions of E–W, N–S and NW–SE at the survey sites: BK-52, BK-53, BK-57, BK-63, BK-66, BK-68, BK-72, BK-75, BK-80; the toppling failure phenomenon can occur with the largest percentages: 10.9%, 12.7%, 11.6%, 13.7% belong to the sections in the directions of the NW–SE and N–S at the survey sites: BK-79, BK-80, BK-81 and BK-83. These results have important significance to support for the highway design and tunnel construction. Acknowledgements This research is supported by the Project of “Research on the application of Block Theory to assess the risk of slope failure along the highway. Case study from km 0 to km 80 on the 3B highway”, Code: TNMT.2018.03.18 of Ministry of Natural Resources and Environment, within the time 2018–2020.

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References 1. Bui TV, Nguyen SH, Nguyen HT (2016) Assessment of slope stability in a landslide area in B’LaoWard, Bao Loc city, Lam Dong province and solutions to prevent landslides. Sci Technol Develop 19:76–85. (In Vietnamese) 2. Goodman RE, Shi GH (1985) Block theory and its application to rock engineering. Prentice-Hall INC, p 337 3. Hoek E, Bray JW (2004) Rock slope engineering. Taylor & Francis Group, London and New York, p 431 4. Nguyen KQ, Dinh TT, Tran VT, Dao DT, Le VC, Nguyen DD, Nguyen TV, Nguyen, VH, Pham VH, Phan CT, Tong DT, Tran TT, Trinh D, Vu K (2000) Geological and mineral resources Map of Vietnam on 1: 200.000: BacKan (F-48-XVI). Department of Geology and Minerals of Vietnam, Ha Noi 5. Nguyen T, Nguyen DD, Uong DK (2012) Integration of analytical hierarchy process model (AHP) into GIS to establish a landslide hazard map of Quangtri province. Hue University J Sc, 74B(5):143–155. (In Vietnamese) 6. Nguyen QP, Phi TT (2014) Rock slope stability analysis using block theory and probabilistic approach: an application at national road No 6, Vietnam In GeoInformatics for SpatialInfrastructure Development in Earth & Allied Sciences GIS-IDEA, pp 209–217. ISBN: 978604-80-0917-5 7. Tran ML, Nguyen QH, Nguyen TK, Hoang, DT, Bui BT (2013) Forecast the risk and intensity of landslide in the Backan city area Vietnam institute for building science and technology (IBST) no. 3 + 4 (2013). (In Vietnamese) 8. Truong PM, Nguyen TD, Tran TA, Nguyen VN (2011) A study on landslides in Danang city by using remote sensing and GIS technology. In: Proceeding GIS 2011 conference, pp 230–237. (In Vietnamese)

Pile Testing Regarding ASTM and Kazakhstan Standards A. S. Tulebekova , Askar Zhussupbekov , Serik N. Nurakov and Ye. Ashkey

Abstract The late year’s globalization of the world economic and social fields implies a development of unified, acknowledged foundations for integration. In the economic field, such foundations are the norms and standards which allow participants of the production process in different countries to speak the same technical language and to apply identical requirements for the products and services produced in different countries. The reform concept of the system of technical regulation in the construction industry was approved by the Government of the Republic of Kazakhstan, as well as in many other countries. The testing of piles according to the ASTM (USA) standard and the GOST (Kazakhstan) standard was discussed. The methods of testing piles by these standards have some differences. The Kazakhstan standard has not changed since 2012. By contrast, the ASTM standard has been updated and accounts for the latest technological developments and methodics of tests including different equipment. The paper includes recommendations on the future modernization of Kazakhstan standards for pile testing and installation. The most relevant issue today is to update the national standards, harmonizing with international standards. Keywords Standard · Test · Pile

A. S. Tulebekova (B) · A. Zhussupbekov · S. N. Nurakov L.N.Gumilyov, Eurasian National University, Astana, Kazakhstan e-mail: [email protected] A. Zhussupbekov e-mail: [email protected] S. N. Nurakov e-mail: [email protected] Ye. Ashkey KGS, LTD, Astana, Kazakhstan e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_46

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1 Introduction As world practice shows construction development directly reflects the economical position of state in the whole world, it is one of the relevant fields for the future advance and development as a whole. The first and the main of them is that the application of the international practice which improves the quality, safety and reliability of construction [1, 2]. The causes of numerous disasters occurred at different times on construction sites in different countries of the world were analyzed and considered in the latest version of standards. Some aspects in international standards balanced system make construction easier, faster and more economical. The international relations expansion including investments of domestic companies in construction abroad, and foreign companies in the construction projects in the Republic of Kazakhstan, entry into the Eurasian Union and the World Trade Organization requires contingence of the normative base, including designing, construction and operation of buildings and structures [3, 4]. In this relation, the harmonization of the construction codes and regulations used today by the construction industry in the Republic of Kazakhstan is being carried out.

2 Field Tests Methodologies 2.1 Dynamic Load Test in Construction Site «Main Mosque» Regarding Kazakhstan Norms Field dynamic tests of driven piles C8-30 with dynamic load at the construction site of the main prayer hall (Haram) of the main mosque object with volume of 30,000 people in Astana. The purpose of the test is to determine the possible depth of the piles and their bearing capacity. Field tests were performed in accordance with the requirements of GOST 5686-2012 “Soils. Methods of field testing piles” [5]. Sixteen test piles were driven in the amount of 16 pieces in the area of the main prayer section of the mosque (Haram). When driving test piles, the “Junttan PM25” pile driver with a hydraulic hammer NN-7A with a mass of percussion part of 7000 kg with a headboard and a weight of 990 kg was used. The completion of trial piles was made in the amount of 16 pieces by a pile-driving installation, which was used for driving piles. The C8-30 piles with a length of 8.0 m and a section of 30 × 30 cm immersed in the ground to a depth of 7.5 m were subjected to dynamic load tests. Field tests of C8-30 piles with dynamic load were conducted at the construction site of the main prayer unit (Haram) of the Main Mosque for 30,000 people in Astana city facility. The test piles C8-30, № 1–16, submerged in the ground to a depth of 7.5 m to the absolute level of the pile bottom 340.41–341.61 m were subjected to dynamic tests.

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Table 1 Results of driving of piles No. of test pile

Abs. marks of the bottom of pile, m

Depth of pile driving, m

ReinforcementRefusal of pile at driving, cm

Refusal of pile, cm

Bearing capacity of pile, kN

№ 12

341.16

6.2

0.42

0.40

0.27

960

№ 13

340.83

6.2

0.43

0.40

0.30

№ 15

341.61

5.8

0.37

0.40

0.30

№ 16

340.71

6.4

0.36

0.50

0.43

№1

340.57

7.3

0.36

0.40

0.34

№2

340.17

7.5

0.53

0.50

0.36

№3

340.88

7.1

0.40

0.40

0.27

№8

340.69

7.1

0.38

0.40

0.23

№9

340.80

7.5

0.50

0.40

0.23

№ 10

341.41

5.9

0.36

0.40

0.28

№7

341.05

6.7

0.38

0.40

0.22

№5

340.60

6.8

0.40

0.40

0.30

№4

341.41

6.5

0.40

0.50

0.38

When driving piles inside the metal cap, wooden liners were used to prevent the pile head from being destroyed. In the process of testing, counting the number of hammer blows on each meter of pile driving was carried out, and on the last meter for every 10 cm of diving, the drop height of the percussion part of hammer was recorded at the same time [6]. The failures of the piles during their driving, on the last dive meter with an impact energy of 40–45 kJ ranged from 0.36 to 0.50 cm (see Table 1). Piling was done by equipment that was used during pile driving with two consecutive pledges of three and five blows, after 20 days from the end of the pile driving. Before pilling, a measuring tape was glued to the pile with a graduation price of 1 mm. Supervision over piling was carried out with the help of a theodolite [7]. Failures of piles at their trimming with impact energy of 25–30 kJ ranged from 0.22 to 0.43 cm. The bearing capacity of piles shipped to a depth of 7.5 m to the absolute level of the bottom of the piles is 340.17–341.71 m, according to the results of dynamic tests amounted to 960 kN. Permissible load on the pile, taking into account the safety factor γ k = 1.4 according to SNiP RK 5.01-03-2002 «Pile foundations» [8] should be taken equal to 685 kN.

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2.2 Field Static Load Test in Construction Site “Grand Astana” Regarding Kazakhstan Norms The construction site (Grand Astana) is located in the capital of the Republic of Kazakhstan Astana city, on the left bank of the Yesil River. The city’s territory is located on the Kazakh shield and does not have tectonic movements, therefore its territory is not considered as seismic [9]. The building sites in the territory of Astana city are taken as the research objects characterizing typical engineering-geological conditions of this region. For each allocated engineering-geological element, private values of parameters of physical–mechanical properties, tests by laboratory methods, characteristics of soil presented in Table 2. Field static load tests were carried out for CFA piles no. CFA1, CFA2, with diameter of 600 mm. Under GOST 5686-12, the equipment of the soil testing unit with static loading should include the following (see Figs. 1 and 2): device for loading piles (typically this consists of jacks); a supporting structure for receiving reactive Table 2 Soil investigation Bottom of soil layer, m Depths

Ground level

Thickness of soil layer, m

Description of soil layer

Physical–mechanical properties of soil E, MPa

C, kPa

ϕ

ρ, g/cm3

0.4–0.8

345.76–346.08

0.4–0.8

Clay

15

40

14

1.95

13.3–12.7

333.26–333.78

12.3–12.5

Hard clay

26

57

18

2.00

22.3–22.9

323.58–324.26

9.0–10.2

Sand with gravel

32

2

38

2.60

26.0

320.76–321.16

3.4–3.5

Sand

34

2

40

2.66

Fig. 1 Field static load test of CFA1 on construction site “Grand Astana” (Building 3)

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Fig. 2 Field static load test of Casing 2 on construction site “Grand Astana” (Building 5)

forces (typically this is a system of beams with anchor piles); a device for measuring pile movements during testing (typically this consists of a system of benchmarks with suitable measuring devices). The distance between the testing piles till anchoring pile is 5d < L 1 > 2.5 m. Reloading was conducted in stages 800 and 400 kN (see Table 3, Fig. 3). Table 3 Soil investigation No. of test pile

Length of pile, m

∅ pile, mm

Reinforcement

Concrete type

Absolute levels of pile, m

Pile length of in soil, m

CFA1

10.5

600

8∅ 20A-III

B25

347.06

346.56

336.56

10.0

CFA2

10.5

600

8∅ 20A-III

B25

347.06

346.56

336.56

10.0

Casing1

10.5

630

8∅ 20A-III

B25

347.06

346.56

336.56

10.0

Casing2

10.5

630

8∅ 20A-III

B25

347.06

346.56

336.56

10.0

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Settlemen t, mm

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

400

800

1200

1600 2000

2400 2800

3200 3600

4000 4400

Casing1 (10 m) CFA1 (10 m) CFA 2 (10m) Casing2 (10m)

Fig. 3 Diagram of load dependence of pile head settlements to determine bearing capacity of CFA and Casing piles

2.3 Pile Testing in Construction Site “KPC Gas Debottlenecking Project” Regarding ASTM The construction site (KPC Gas Debottlenecking Project) is located in the Karachaganak Field. Reaction system for load test piles is presented in Fig. 4. Figures 5 and 6 show the results of pile test. Safety factors are equal two regarding requirements ASTM [10]. 1. Main beam H = 736 mm, L = 6510 mm; 2, 3. Reaction beam H = 708 mm, L = 5620 mm; 4. Reaction transfer tube; 5. Hydraulic jack 250 t; 6. Load cell; 7. Metal plate; 8. Concrete block 600*600*1200 mm; 9. Test pile; 10. Anchor pile;

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Fig. 4 Reaction system for load test piles d = 600 mm

Fig. 5 Data of static load test [11]

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Fig. 6 Graphics for testing pile

11. Reference system; 12. Screw metal piles for reference systems; 13. Clamp; 14. Wooden lining; 15. Rebar L = 900 mm.

3 Geotechnical Specificity of ASTM and Kazakhstan Standards After comparing the methods of soil testing with piles according to the American standard, it was noticed that more detailed requirements are presented, most of which are not mentioned in the state standard. The Kazakhstan standard considered two measurements. But ASTM regulated six measurements (see Table 4). However, the Kazakhstan standard does not take into account the fact that when two or more jacks are used, each must be equipped with a manometer. There is only one common feature on the manifold. It allows for monitoring the work of the jacks and prevents possible irregularities in their operation, thus avoiding failure in the tests [13].

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Table 4 Principal differences of American Standard and Kazakhstan norms [12] Kazakhstan Standards

ASTM

The parameter of experimental stand for test The distance between the testing pile till anchoring pile

5d < L 1 > 2.5 m

3d < L 1 > 1.5 m

The distance between testing pile till

5d < L 2 > 2.5 m

L2 < 2 m

Devices and equipment For loading

Jack

Jack with Spherical prop

Measurement of load on top pile

Manometer

Manometer

–

Dynamometer fixed for each jack

–

Tensometer

Measurement of load on all length pile

Experience has shown that tests conducted according to the American standard make them more accurate and reliable. The experience that has been gained using the ASTM standard during tests facilitates obtaining test results with maximum reliability.

4 Conclusions The process for adaption of international standards to Kazakhstan ground and construction conditions must be gradual. The first step was to adapt the foreign technical documentation to the national technological environment, to develop appropriate methodology for assessing conformity to educate builders and designers to develop appropriate training programs, handbooks and manuals, translation to the official language. Recommendations for adaptation international standards in pile testing to Kazakhstan ground and construction conditions regarding investigations as follows: more detailed requirements are designed for the control equipment which are used in static tests.

References 1. Akhmetov NS, Tulebekova AS, Kozhakhmet M (2017) Factorial analysis as a basis for reducing the risk of an investment project. Int J Econ Res 14(9):89–94 2. Tulebekova AS, Zhussupbekov AZ, Mussabayev T, Mussina S (2019) Features of investigation of soil according to Kazakhstan norm and International Standards. In: Hemeda S, Bouassida M (eds) Contemporary issues in soil mechanics. GeoMEast 2018. Sustainable Civil Infrastructures. Springer, Cham, pp 142–148

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3. Kodsi SA, Oda K, Awwad T (2018) Viscosity effect on soil settlements and pile skin friction distribution during primary consolidation. Int J GEOMATE 15(52):152–159 4. Awwad T, Mussabayev T, Tulebekova A, Jumabayev A (2019) Development of the computer program of calculation of concrete bored piles in soil ground of Astana city. Int J GEOMATE 17(60):176–182 5. GOST 5686-2012 (2012) Methods for field testing by piles. Research Institute of Bases and Underground Structures, Moscow, Russia (2012) 6. Zhussupbekov AZ, Tulebekova AS, Awwad T, Mussabayev T, Tuleubayeva A (2019) Geotechnical specification of American and Kazakhstan Standards in pile testing. Int J GEOMATE 17(63):157–163 7. Zhussupbekov AZ, Muzdybayeva TK, Lukpanov R (2013) Comparative analysis of methodics of testing pile by ASTM and GOST standards. Geotechnical and Geophysical Site Characterization 4. In: Proceedings of the 4th international conference on site characterization 4, ISC-4, pp 134–138 8. SNiP RK 5.01-03-2002 (2002) Pile foundations 9. Zhussupbekov AZ, Tulebekova AS, Lukpanov R, Zhumadilov IT (2016) Comparison analysis of features in Eurocode and Kazakhstan norms requirements. Challenges and Innovations in Geotechnics. In: Proceedings of the 8th Asian young geotechnical engineers conference, 8AYGEC. Springer, pp 251–257 10. Standard Test Method for Deep Foundations Under Static Axial Compressive Load, ASTM D8169/ D8169M–18 11. Report № 2. KGS, LTD: KPC Gas Debottlenecking Project (2018) 12. Tulebekova AS (2015) Control equipment for pile test according to American and Kazakhstan standards. Mod Appl Sci 9(6) 13. Smolin BS, Zaharov VV, Puzanov VV (2010) Features pile load test by ASTM. International Symposium, Russia. pp 12–16, Tom 4

Effective Structure for Strengthening the Road Embankments on Unstable Mountain Slopes A. A. Piotrovich, T. F. Mirzoev and A. N. Magdalinsky

Abstract The paper deals with the issues of effective protection against rock landslides in the cold regions of the Russian Far East. On the mountainside at the base of the road embankment, there is a possibility of sprawling blocks of fractured rocks. The authors describe the original structure for strengthening the foundations of road embankments on unstable mountain slopes. The design of the structure redistributes the vertical loads from the embankment. As a result, the soil mass is compacted compensating for the landslide pressure of the soil. The paper presents the results of design calculations of the structure elements. A new spatial scheme of the soil mass under the embankment increases the reliability of the road structure. Keywords Landslides · Embankment · Strengthening · Structure

1 Introduction Unstable slopes, namely landslides, are one of the most common hazardous geological processes. During the construction, they interfere and prevent the important large areas which are often located near or on the slopes from being used successfully. In this regard, the issue of developing the most effective technological solutions for the construction of landslide protection structures is very relevant. The immediate causes of landslides are both natural and man-made (earthworks, ground vibration from transport, blasting). Up to 70% of landslide movements occur to one degree or another in connection with human activities [1]. During the construction of roads in the mountainous northern regions of the Far East of Russia, engineers widely used explosive methods for the development of rocks and permafrost soils [2] which led to an increase in the fracture of the slopes and foundations of the subgrade. Under the conditions of permafrost, watering of slopes, and seismic phenomena characteristic of the Far Eastern North, the landslide A. A. Piotrovich (B) · T. F. Mirzoev · A. N. Magdalinsky Far Eastern State Transport University, Khabarovsk, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_47

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hazard on railways and highways increases after a considerable time interval as a result of rock cracking. The paper showcases such a landslide hazard. There are various approaches to dealing with landslides depending on the needs, risks, availability of funds, and the degree of a landslide hazard. Specific measures are grouped according to the chosen option of a landslide mitigation strategy. These options include such approaches as “Avoidance” (or “Bypass” in Russian practice), “Do nothing,” “Maintenance,” “Selective stabilization,” and also “Conventional stabilization” [3]. The latter approach has virtually no alternatives for the reconstruction of the existing road. Currently, there are a significant number of methods to prevent landslide hazards [4]. They include monitoring of the development of hazardous geological processes, drainage and drainage of landslide formation zones, redistribution of soil masses, an artificial change of soil properties, and measures to retain and fix the landslide massif. Performing each event separately does not eliminate all the causes that lead to landslide phenomena, therefore it is necessary to apply them in combination. The core of such a complex is a holding (supporting) structure. The modern process of improving the structures of holding facilities is aimed at increasing their efficiency and reliability taking into account the specific features of particular landslide sites [3, 4]. The original approach of the authors to designing holding facilities for the roads on unstable rock slopes allowed them to design a new structure which is described below.

2 Methods and Materials: The Main Idea One of the most effective supporting structures for rock landslides is spaced pile walls [1, 4, 5, 8] which create mechanical resistance to the movement of landslide masses. If necessary, various methods of anchoring pile walls in anti-landslide structures are used as a method to compensate for significant horizontal loads on the supporting structures [5–8]. The authors of this paper analyzed the existing project of stabilizing the roadbed on an unstable rock slope in order to develop more efficient structures for landslide protection. The reconstruction site is located in the Neryungri district of the Republic of Sakha (Yakutia) and is part of the Amur–Yakutsk Railroad (AYM). The length of the deformable section is 0.22 km. The existing transverse profile of the considered area is a mound on a shelf with changing slopes (Fig. 1a). In the example, considered blocks of a fractured rock spread at the base of the roadbed. This geological process is a landslide in rocks and refers to the so-called rock landslides. The reason for the activation of the landslide was the cracking of rocks as a result of the use of explosive methods of work in the construction of the shelves in the rock slope.

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Fig. 1 An example of a landslide slope on a mountain site (Neryungri District, Russian Federation): a is a transverse profile of a site with a retaining wall of bored piles; b is a photo of a landslide crack opening

During the operation of the road, seismic effects, intermittent exposure to groundwater, frost erosion, and vibro-dynamic loads from railway rolling stock led to the spread of rock blocks composing the base of the railroad bed and the counter dam to the right of it. There are two sliding surfaces of the landslide massif on the territory shown (Fig. 1a). The formation of the lower surface was the result of man-made processes (blasting during construction, vibration from transport), as well as periodic exposure to groundwater and seismic effects. The surface to the right of the roadbed (upper) was formed as a result of a large slope of the counter dam slope. Destroying the slope, the landslide created a specific landslide topography on this site with opening cracks within the main site of the roadbed and the surface of the counter-bunket (Fig. 1b). Thus, the landslide massif is divided into two zones: the active landslide zone (upper zone in Fig. 1a) and zones with the rockslide potential (lower zone). As a prototype, there was adopted a construction designed for this particular site. To stabilize the roadbed, the design organization proposed a set of anti-deformation measures, the main of which is the construction of a retaining wall of bored piles

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in the cracking zone to hold the railway embankment on the slope (Fig. 1a). Such constructions are widely used for stabilizing mountain landslide sites [4]. There are a number of features of the slope behavior that can lead to serious concerns in terms of the reliability of its fixation. As stated by engineering-geological surveys, deformations of the base of the roadbed occur due to the inflow of groundwater along fractures. The inflow of the underground water in the winter period is associated with tectonic disturbances, which were provoked by construction work. It is in winter that the further opening of cracks in the rock mass is activated. If we predict the further development of landslide processes, then, combined with seismic and man-made effects, the spread of blocks below the retaining wall will continue. Taking it into account, the design of the pile retaining wall became quite massive. Bored piles with a diameter of 800 mm are located along the sole of the existing roadbed with a pitch of 1800 mm. The piles are interconnected by a reinforced concrete grillage 800 mm wide and 600 mm high. The drilling of wells was done on weakened soils, and piles with a length of 12.0 m were fixed in a solid rock foundation. Such a supporting wall is distinguished by a high bearing capacity and in combination with drainage measures ensures the stability of the landslide slope. However, when choosing the best design for strengthening landslide slopes, one should proceed not only from a technical result. When evaluating a design and technological solution in these cases, a number of factors, both technical and economic, should be taken into account [8]. A special role for transport facilities is played by both construction costs and associated costs in the operation of a transport facility. The development of an alternative to the proposed solution was carried out as a result of the experience that the authors gained while using the methodology of a system development of design and technological solutions [9]. The techno-genesis of the process of designing such solutions goes through certain phases of development under the influence of the external environment (super-system). The development goes in a spiral, on each turn i of which the phases of the life cycle of the process Gi –L i –T i –Ri are repeated, where Gi is goal setting (research and setting tasks); L i —restrictions for development (identification of obstacles to the achievement of a result); T i —solving problems at a technical level (technical capabilities as a product of engineering creativity); and Ri —achieving the result (development of design and technological documentation, implementation at the sites). The use of the system development methodology presented in this paper is illustrated by a description of the progress in developing more effective structural and technological solutions for the construction of a landslide protection structure. The goal of G2 was set to improve the design of the structure to stabilize the landslide slope in the conditions of operating train traffic. A number of economic considerations were taken into account. First, as the experience of the construction shows [4], pile walls have a high cost. The volume and therefore the cost of work on the construction of the pile wall are quite large, which is typical of such a huge structure. Therefore, a reduction in the scope of work is relevant for any stabilization measure. Secondly, as a result of the above-mentioned factors, the duration of construction work along the embankment increases. Carrying out such work along the existing

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railway line will require stopping traffic and so-called technological “windows.” Therefore, the project implementation time affects not only the costs of the contractor, but also the additional costs incurred by the railroad owner, caused by interruptions in traffic and reduction of the speed in the reconstructed section. Consequently, the problem of reducing the volume and duration of construction was formulated as obstacle L 2 , which required the interruptions in the train traffic. At the creative stage of the formation of technical capabilities (T 2 ), the internal elements of the structure and the corresponding technology were improved. As an alternative version of the supporting structure for the road embankment, we have developed a new type of design for stabilizing the foundations of earthworks, namely “Ground balcony.” From the technical point of view, the landslide area below the pile wall is an active landslide, and the massif in front of the wall has the so-called rockslide potential. The proposed construction contains a supporting structure in the form of a triangular frame made of bored piles connected on top with special rods in the shape of flexible rods (Fig. 2). The pairing of the inclined pile with the frame elements is made as a swivel. The plane of the frame is perpendicular to the axis of the railroad. The vertical frame stand is located on the upland side, and the inclined one is under the embankment.

Fig. 2 Schematic diagram of the proposed design: a cross section; b 3D model of the frame structure; 1—vertical pile; 2—inclined pile; 3—transverse thrust; 4—longitudinal links between frames

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In its turn, the adjacent racks of frames are connected by rods. The distance between the frames is determined by calculation. Loads from the road embankment are transmitted through the traction (flexible, for example, steel rod) to the fractured ground inside the frame. As a result, sedimentation and spreading of rock blocks may occur. The sliding blocks are wedged between the piles, trying to push them apart. But on the other hand, the same loads from the embankment on the horizontal rod are redistributed causing horizontal forces in the piles arising from sagging thrust. These horizontal forces are directed inside the frame and cause compression of the fractured mass or a compression effect. As a result, landslide pressure is compensated for the soil, and the soil massif inside the frame will be compacted and stabilized. It is worth noting the fact that thanks to the vertical rack this design makes it possible to hold blocks of fractured soil “inside itself,” preventing it from moving out. The magnitude of the embedment of the vertical rack in the carrier layer is determined by calculation. This construction is intended for the construction and reconstruction of road sections of the roadbed, the base of which consists of rocky fractured blocks. An essential condition for the application of the structure is the presence of a strong mountain slope on one side (Fig. 2). As a result of the work done, an application for the grant of a patent for inventions was drawn up and filed.

3 Results As a result of the system development of construction R2 , the design and technological documentation has been completed for the construction of an “unpaved balcony.” Below are some of the design parameters. The calculation was based on the critical combination of loads when the soil of the active part of the landslide to the right of the inclined pile slid down. As a possible dangerous situation, tearing off a structure with a “ground balcony” from the rest of the array, i.e., exfoliation of the vertical pile from the rock massif of the mountain slope was considered. For the fissured dolomite massif, the limiting values of frame pitch B are taken from the characteristics of the irregular blocking of the array [8] from 1.0 to 3.0 m. The model was calculated in the software complex Lira-SAPR 2013 using the finite element method [10] under the following initial conditions: frame pitch B = 1.0–3.0 m; embedment depth he = 6.0 m; the depth of attachment of the inclined pile ha = 3.0–6.0 m; diameter of a vertical pile is 600 mm; and diameter of inclined pile 200 mm. The choice of this particular software complex is determined by the fact that it implements the calculations regulated by the documentation of the Russian Federation in the field of design of responsible structures [11, 12]. Calculations on the model allowed us to determine the main design parameters of structural elements.

Effective Structure for Strengthening the Road Embankments …

M, tm

250 200 150

457

embedment depth 3m embedment depth 4 m embedment depth 5 m embedment depth 6m

100 50 0

1

2

3

frame pitch, m

Fig. 3 Diagrams of dependences of efforts (moments of force) in a vertical

Figure 3 shows the values of moments in the most loaded structural element, i.e., a vertical stand in a critical situation. Significant values of bending moments at critical combinations of loads in a vertical pile caused its large diameter and thick reinforcement in comparison with an inclined pile. It should be noted that the values of the moments of effort above 200 tm are not acceptable because of the excessive reinforcement of the structure which must be used to avoid unacceptable movements of the frame elements. At certain values of the loads and a combination of local factors (for example, the presence of fractured rock soil behind the pile), there is a possibility of anchoring the vertical pile into a slope. In this case, the useful effect of the anchor pile, “soldier pile” [4, 5, 7], is used, which increases the stability of the structure to bending forces. The vertical pile will have a diameter of 200 mm. Anchoring will provide an opportunity to increase the width of the subgrade of the road embankment. In the new design, the following results R2 are obtained, which are useful from the point of view of goal G2 . 1. The size and number of piles are smaller than in the original version. The diameter of the vertical pile is 600 mm. Length is 7.0 m due to the location above the sliding surface (Fig. 2). The pitch between the frames is several times larger than the pitch of the piles when constructing a vertical pile wall. The total volume of reinforced concrete was 159.4 m3 versus 830 m3 ; the volume of drilling work was 1022 rm against 1476 rm. Hence, there were savings in the volume of work and the cost of construction. 2. Accordingly, the construction time and the amount of associated costs connected with interruptions in the movement of trains have been reduced. 3. “Ground balcony” in the presence of one solid surface (wall) reduces the level of anthropogenic impacts on the foundations of structures on a “potential landslide.” 4. The created computational model gives the opportunity to choose the design option for various conditions of fracture of the array (block sizes) under similar conditions. For the customer and the contractor, the ability to set “the optimum level of work” [8, p. 284] is important, when choosing the option of supporting construction in the complex of landslide control.

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5. The model allows to modify the dimensional parameters of the structure to suit the technical equipment of the contractor. 6. The use of the anchor version of the design opens up a wide range of opportunities to apple the “ground balcony” in potential landslide massifs in order to build highways, individual buildings, etc. 7. The application of the developed design instead of massive supporting walls on narrow soil shelves makes it possible to construct a roadbed of normal width.

4 Conclusion The technical tasks solved by the proposed new structure are the following: expanding the scope of application, improving the efficiency of strengthening rockslide massifs, shortening the project implementation timeframe, reducing construction labor intensity, and reducing the cost of work. The principle of “compression” of a fractured rock mass within the frame structure expands the boundaries of the design of landslide protection measures, especially for potential rockslides caused by man-made loads. The application of the proposed structure is directed against the sudden massive collapse of the massif along a single line. The developed model for calculating the structure allows designers to choose the dimensional parameters of the structure for various characteristics of the rockslide massif (fracture, block size, etc.) under similar conditions. For the contractors, it is important to choose the dimensional parameters of the structure suitable for their own technical equipment.

References 1. Drannikov AM (1956) Landslides. Types, causes of formation, control measures. Kiev 2. Makartsev MK (ed) (1991) The Baikal-Amur railway: technical report on surveying, design and construction (1974–1989). Moscow 3. Machan G (2006) Landslide mitigation. In: Engineering geology and geotechnical engineering symposium. Logan UTm Portland, Oregon 4. Cornforth D (2005) Landslides in practice, investigation, analysis, and remedial/ preventative options in soils. Wiley, Hoboken, New Jersey, USA 5. Nikitenko M, Boiko I, Sernov V, Chernoshey N, Sikorae N (2013) anchorage of retaining walls and antilandslide structures. In: 11th international conference on modern building materials, structures and techniques, (Procedures engineering) MBMST 2013, vol 57. Vilnius, Lithuania, pp 808–803. https://doi.org/10.1016/j.proeng.2013.04.102 6. Jones CJFP (1996) Earth reinforcement and soil structures. Thomas Telford edition published, London 7. Piotrovich A, Yang G, Su D (2013) Experience in accounting for horizontal lateral deformations when designing reinforced ground structures on the railways of the PRC. Trans Constr 10:20–23

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8. Willie DC, Mah CW (2005) Rock slope engineering: civil and mining, 4th edn. Spon Press, Taylor & Francis, London and New York 9. Piotrovich AA (2018) Some results of systemic study of design and technological solutions for stabilizing ground structures. In: International multi-conference on industrial engineering and modern technologies. IOP Publishing, IOP conference on series: materials science and engineering, 463. 022059.https://doi.org/10.1088/1757-899X/463/2/022059 10. Official website of LiraLand, https://help.liraland.ru. Last Access 13 Jan 2019 11. Loads and impacts (2016) The main provisions. Ministry of Construction of Russia, Moscow 12. Concrete and reinforced concrete structures (2011) The main provisions. Minregion of Russia, Moscow

Complex Analysis of Bored Piles on LRT Construction Site in Astana Askar Zhussupbekov , Abdulla Omarov , Nurgul Shakirova and Daria Razueva

Abstract At the present time, Astana city is going on works by construction public transport system light railway transport (LRT). The article considers the project of LRT on problematical soils of Astana. The foundation of bridge created from bored piles with cross-section diameter of 1.0–1.5 m and length of 8–55 m. Design bearing capacity of each bored piles are from 4500 to 9500 kN. This paper presented results of integrity test (by ASTM D6760-08) and static load tests (by GOST 5686-94) of bored piles. In those conditions it is very important cases to control the integrity of concrete body of each bored piles. For checking the integrity which applying a Cross-Hole Sonic Logging method. Currently the non-destructive testing method are a cross-hole sonic logging offers the most reliable technique for assessment the integrity of bored deep pile foundation on construction site. Integrity inspections performed after installation are often the most reasonable alternative available to assess the shaft quality. The results used for interpretation the data of real site. Finally, some recommendations are presented for testing methods suitable for problematical ground conditions of Kazakhstan. Keywords Pile · Cross-Hole analyzer · Integrity · Champ · Field test

1 Introduction A first phase of Astana LRT construction project starts from Astana International Airport and ends at the new railway station. Length of LRT is 22.4 km with 18 stations (see Fig. 1) [1]. The foundation of bridge is created from bored piles with cross-section diameter of 1.0–1.5 m and length of 8–55 m. The foundation of each bridge pear design 4 or 6 bored piles, which depended to vertical loads from upper structures. Design bearing capacity of each bored piles are from 4500 to 9500 kN. Widths between piers of LRT are 30 m. A strength quality of concrete of foundations is B40. A. Zhussupbekov (B) · A. Omarov · N. Shakirova · D. Razueva L.N. Gumilyov, Eurasian National University, Astana City, Kazakhstan e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_48

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Fig. 1 Perspective view of LRT near new railway station of Astana, Kazakhstan

Fig. 2 A plan of required pile lengths for LRT project

Figure 2 introduces a map of locations of foundations and the required pile lengths of LRT (from the New Nazarbayev Airport to new railway station).

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2 Engineering Environment of Construction Site The proposed site is located in the South part of Astana city and in the middle-upper part of diluvia Plain of Ishim River. It is flat in general, but low in South–West and slightly high in North–East. The ground elevation is about 345–360 m. The climate of Astana is typical continental with cold, long, and snowy winter; generally, it starts to snow in middle of November, the winter period lasts 130– 140 days, and the average temperature in January is minus 25 °C. According to the detailed investigation report, the stratum in the site, according to cause and age, can be classified into four main categories, i.e., artificial layer, alluvium and diluvium in quaternary, Carboniferous stratum, and Devonian stratum, and it may be further classified into 7 major layers and sublayers according to formation lithology. Lithologies, characteristics, and distribution regularities of all soil layers from up to down successively are: silt layer, silty clay layer, silty sand and coarse sand layer, clay layer, weathered sandstone layer, and slightly weathered sandstone layer. This exploration ends up with Devonian bedrock. When clay layer is used for the soil layer of pile foundation sidewall, the side friction is superior to that of sandy soil of quaternary deposit and may be adopted as supporting layer of pile side. When weathered sandstone layer is adopted as the soil layer of pile foundation sidewall, the side friction is superior to that of gravel soil of quaternary deposit and may be adopted as supporting layer of pile side. When slightly weathered sandstone layer is adopted as supporting layer of pile tip on rock-socketed pile. This layer is favorable supporting layer of pile tip on pile foundation. According to the evaluation results, the shallow soil in the site has moderately corrosive influence on concrete structure while has weakly moderately influence on the bar in reinforced concrete structure. The buried depth of water level is 1.50– 6.00 m. Based on the evaluation results, the underground water in the proposed site is strongly corrosive to the concrete structure; in the case of long-term water immersion, it is slightly corrosive to the bars in reinforced concrete structure, while in the case of alternation of wetting and drying, it is moderately corrosive to the bar in reinforced concrete structure. Freezing-thawing environment. The proposed site is within the severe cold section; as for members within the frozen soil depth range, the concrete frequently contacts the underground water containing chloride salt, and the effect grade of freezing-thawing environment may be considered as D3; as for members below the frozen depth, the effect grade may be considered as D2; as for concrete members of building and structure above ground, in case the concrete frequently contacts water, the effect grade of freezing-thawing environment may be considered as D2, in case the concrete is in water-saturated state for long term, the effect grade of freezingthawing environment may be considered as D3.

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According to the comprehensive analysis based on the survey in combination with regional geological conditions, unfavorable geological actions affecting the site do not exist.

3 Static Load Pile Testing Static load testing of bored piles was conducted in construction site of LRT in Astana, Kazakhstan. This test is used for measuring the axial deformation to determine the bearing capacity of deep foundations. Static load test (further SLT), one of the more reliable field tests for analyzing the pile bearing capacity. In this case SLT test used for to get the settlement data. The measured relationships between the pile head load, L and the head settlement, S of the test piles are shown in Fig. 4. The bored piles have diameters (diameter or D) of 1000–1200 mm and from 23.6 to 29 m depths. Testing platform performed itself as a system from steel, which consists of support beams and platforms located on equidistant distances from the center of main beam (see Fig. 3). Standard—SNIP RK 5.01-03-2002 [2]—ultimate value of settlement of the tested pile is determined as and depending on category of construction is equal to 16 or 24 mm. The last argument shows conditional character of SLT method. According to Kazakhstan, standard 1% of constructed piles on construction site must be tested by SLT, but at least 2 SLTs in a site must be done. Field soil testing with piles on the territory of Kazakhstan and CIS countries is carried out in accordance with the requirements of GOST 5686-94 [3]. Static soil testing for bored piles starts after reaching the strength of concrete more than 80% of the project. According to the professional standard “Code for Durability Design on Concrete Structure of Railway” (TB 10005-2010) [4], the environment of concrete structure is classified into 6 types, i.e., carbonized environment, chloride environment, chemical corrosion environment, sulfate physical attack environment, Fig. 3 Static load test of bored pile in construction LRT in Astana, Kazakhstan

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Fig. 4 Load–settlement diagram of static load tests by GOST

freezing-thawing environment, and abrasion environment. The effect grades of various types of environment are classified according to the conditions of the project and in combination with the design conditions [4]. For SCL was used following equipment such as: – device for pile loading(jack); – Support structure or platform for perception reaction forces (cargo platform); – device for measuring the displacement of the pile during the test (the reference system with measuring instruments) [5]. A device for loading piles must provide coaxial and central transfer loads to the pile, the possibility of transferring loads to feet, and the constancy of pressure at each loading step. The distance from the axis, the full-scale pile test to anchor the pile must be at least 3 diameter of pile, but not less than one and a half meters. Instruments for measuring deformation (displacement) of piles (deflectometer) should ensure the measurement accuracy of 0.1 mm. The number of devices installed symmetrically at equal (no more than two meters) distance from the pile under test must be at least 2 units. The deflectometer is used a steel wire of 0.3 mm diameter. Before beginning the test, wire must be pre-stretched two days with load of at least four kilograms. During the test, the load on the wire should not be more than one and a half kilograms. The loading of piles produces uniformly without shocks with load steps, which value are established by the test program, but is taken no more than 1/10 of the programmed maximum load on pile. At the end of the full-scale burial piles in coarse soils, gravelly and dense sands and clay soils of hard consistency allowed the first three stages of the load is taken equal to 1/5 of the maximum load specified in the program. On each loading the full-scale pile removed the reports from all devices for measuring deformation as follows: zero report—before loading the pile, the first report immediately after application of the load, the field of this series of four reports at intervals of thirty minutes and then every hour until the conditional stabilization of deformation. As criteria of the stabilization tests of soil for SCL test takes speed of settlement of piles on a given loading level not exceeding 0.1 mm in the last 60 min of observation, if at the lower end of the pile lie sandy soil or

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Table 1 Results of field piling static loading tests #

Pile #

Pile L, m

Pile D, m

Load, kN

S, mm

Static load test 1

Pile-1 (PR3-3)

27.5

1.2

9372.41

10.87

2

Pile-2 (A-B/5-2)

24.6

1.2

7411.04

4.18

3

Pile 3 (GR18-2)

29.0

1.2

8561.1

2.94

4

Pile 4 (CR18-2)

23.6

1.0

8275.73

8.4

clay soils from hard consistency to low-plastic consistency, as if under the lower end of the pile rest to the clay soils from high-plastic to fluid consistency, then two o’clock observation. Test load full-scale pile should be brought to the point where the total settlement of pile is not less than 40 mm. At the end of the full-scale bored piles in coarse dense sand and clay soils of hard consistency, load must be reduced to the value provided by test program, but not less than one and a half the value of pile carrying capacity determined by calculation or calculated resistance of pile depended to materials. Unloading piles produce stepwise after reaching maximum load equal to twice (in one-step) values of the steps of loading each stage delayed at least 15 min. Reports for measuring deformation are removed immediately after each stage of discharge and within 15 min of observation. After complete discharge (zero) observations of elastic displacement, piles should be done within 30 min at the sandy soils rests below the lower end of the pile and 60 min with clay soils. Results of soil test of pile are made “load-settlement” and “strain-time” by steps of loading and unloading. Table 1 presents a comparative analysis of the bearing capacity of piles, obtained by different methods.

4 Cross-Hole Sonic Logging Test “Cross-hole sonic logging” (CSL) is a testing method for the determination of pile integrity in accordance with relative change of such acoustic parameters as sonic time, frequency, and amplitude attenuation when actual measured sound wave transmitted in the concrete media, shooting, and receiving sound waves among pre-buried sonictesting tubes of the pile (ASTM D6760–08 (2008)) [6].

4.1 Pile Testing Procedure By sending ultrasonic pulses through concrete from one probe to another (probes located in parallel tubes), the CSL procedure inspects the drilled shaft’s concrete homogeneity, and extent and location of defects, if any. An arrival time of pulse at the receiver probe and signal strength is affected by the concrete or lack there.

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For equidistant tubes, uniform concrete provides consistent arrival times with wave speed 3500–4500 m/s and signal strengths. Non-uniformities such as contamination, soft concrete, honeycombing, voids, or inclusions exhibit delayed arrival times with reduced signal strength (Recommendations on Piling (2013)) [7]. The CSL testing should initially be performed with the transmitter and receiver probes in the same horizontal plane in parallel tubes unless test results indicate potential defects, in which case the questionable zone may be further evaluated with offset tests (source and receiver vertically offset in the tubes). CSL testing performs between all adjacent perimeter access tube pairs and across at least the major diagonals within the drilled shaft. Prior to actual testing, all the access tubes were first checked to ensure that the tubes are not contaminated or blocked, and that they are reasonably straight, clean, and free from any internal defects for the clear passage of the probes. This is done using a dummy probe to test access and at the same time record length of each tube. The access tubes are identified in the field as numbers 1, 2, and 3. These are numbered sequentially in the clockwise direction. Prior to the test, the tubes are filled to the top with clear water. To ensure good acoustic coupling between the probes and the water in the tubes, the probes are cleaned and made fully saturated before each immersion. The transmitter and receiver probes are then inserted inside the first two selected tubes for logging. If all the tubes are clear (not blocked), the tests normally start from the bottom progressing to the top. On the other hand, if any or all the bottoms of the tubes are blocked (i.e., bottoms are not in same elevation), then tests are conducted starting from the top to bottom. A specific scan would then stop at the higher elevation of the two tubes being used, and this will now be reflected as the bottom of the specific record (but does not necessarily be the bottom of the pile). Measured pile length will therefore be shorter than actual. The cables of the probes are running for depth encoding. When the testing method of low-strain reflected wave method or cross-hole sonic logging is used, the concrete strength of tested pile shaft should not be less than 70% of the designed strength, and the strength of pile shaft should not be less than 15 MPa. The classification of pile integrity for every test pile shall be presented during the assessment of testing of pile integrity. It shall conform to Table 2.

4.2 Field Pile Integrity Test by Cross-Hole Sonic Logging The ultrasonic integrity tests have been carried out using cross-hole analyzer on June 2, 2017. Piles PR4-4, PR5-3, PR6-2, and PR7-2 have been tested. In Table 1, the data of the test piles are summarized. The diameter of the test piles was given as 1.2 m, the concrete strength of B40. The test piles have been installed with reinforcement cages containing steel tubes of diameter 42 mm. Ultrasonic measurements were executed at all distances available between the access tubes with a vertical resolution of 5 cm. In Fig. 5, the test situation at site and the location of the test pile are shown.

468 Table 2 Classification table of pile integrity

A. Zhussupbekov et al. Classification of pile integrity

Classification principle

Type I

Complete pile shaft

Type II

Slight defect on the pile shaft

Type III

Obvious defect on the pile shaft

Type IV

Serious defect on the pile shaft

Note Type I and Type II are acceptable piles for Type III, it shall be studied by both the construction unit and the design party to determine if it can be used, or a remedy proposal is confirmed for Type IV, it is unqualified

Fig. 5 Cross-hole sonic Logging test on construction site LRT in Astana

Table 3 summarizes the results for each measurement distance between the access tubes for all test piles. The measured depth is a result of the free accessible tube length less than the length of the measurement probe (transmitter and receiver). The following Figs. 6 and 7 show the results of the ultrasonic integrity tests. Deviations from the concrete continuity or homogeneity (in the scale of decimeter) are found by relevant changes in speed or energy absorption, and the transmitted waves are shown in Fig. 7.

5 Conclusions Results of CSL testing presented following concluding remarks: the defects had different issues as well as low quality of concrete (strength is not reach to the project), non-observance of the work of production technology or soil ingress into the concrete pouring into the drilling shaft. The soil condition of construction site affected to the

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Table 3 Results of ultrasonic integrity tests Pile No.

Direction between access tube no.

Space between access tubes (m)

PR 4-4

1–2

0.756

6.96

2–3

0.682

8.12/6.15

3–1

0.763

6.96

1–2

0.665

10.17

2–3

0.780

10.17

3–1

0.680

10.20

1–2

0.747

11.63

2–3

0.715

11.62

3–1

0.746

11.60

1–2

0.752

8.17

2–3

0.775

8.11

3–1

0.637

8.12

PR 5-3

PR 6-2

PR 7-2

Length measured (free accessible tube length) (m)

Results/comments

Homogeneous concrete, no anomaly detected, tube 1 only accessible to a depth of approximately 7 m Homogeneous concrete, no anomaly detected Detected, between 1.35 and 1.40 m lower arrival time in all 3 measurement directions, (reduction of AT is vimax .

where ai vi vmin vmax

weight coefficient of the digraph; real value of the factor (e.g., temperature, pH of water, freezing depth); the minimum value of factor; the maximum value of the factor.

For the analysis of meteorological parameters, it is possible to use different interpolation methods [9] or double exponential Gumbel distribution. The last makes it possible to determine the value of the parameter and, as a consequence, the value of a certain type of factor depending on it at any lifetime period: xi (t) = x¯i +

σxi (ln t − y¯ ), σy

(2)

where x¯i arithmetic mean of the ith meteorological parameter; standard deviation of the ith meteorological parameter; σxi y¯ , σ y dimensionless quantities that depend on the sample data and define the Gumbel tables. Modeling changes of factors values (V i ) included in the oriented graph is performed on steps S = 1, 2, …, n. In this research, it is assumed that one step is equal to 10 years. The value of the factor at the vertex i of the digraph at the step S is determined by the equation [10]: Vi(S) = Vi(S−1) +

n 

a ji · V j (S−1) ,

(3)

i, j=1

where V i(S−1) , V j(S−1) i, j aji n

value of factors on the step S − 1; vertex numbers; weight coefficient; number of factors included in the calculated factor, factors having a direct impact on this factor.

The method of pulse process establishes relation of damaging effect of factors and age of the engineering structure. In common case, the obtained relation has the form of a monotonically increasing exponential curve, which makes it difficult to determine the critical lifetime of engineering structure. In this regard, it is proposed to analyze the results by cluster analysis.

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2.2 Cluster Analysis Cluster analysis is an accompanying quantitative method of system analysis. To determine critical lifetime of engineering structures, its ages are grouped into clusters (the sum of homogeneous elements). Elements within one cluster have a high degree of similarity. The result of cluster analysis is a dendrogram, on the basis of which the critical lifetime is determined by the allocation of clusters. Clustering is based on the minimum distance in Euclidean space. Between each two values of the damaging effect of factors corresponding to two different steps, the distance in Euclidean space (d s ) is calculated [10]: Vn(si) − Vn.av. Vn(si+1) − Vn.av. ds = − , V V n.d.

(4)

n.d.

where V n(s) V n.av. V n.d.

value of damaging effect of factors on steps i and i + 1 derived from the pulse process; average value of damaging effect of factors; deviation of value of damaging effect of factors.

The result of calculations is a matrix by which the minimum distance for each value of damaging effect corresponding to a certain step is determined. Allocation of clusters is carried out by successive comparison obtained values of minimum distances with the criteria: 0.25; 0.5; 1.0; 1.25, etc. (these criteria are postponed along the ordinate axis). For example, if the resulting d s value is less than 0.25, it is clustered at 0.25, otherwise compared with the subsequent criteria. The cluster uniting the greatest number of steps (ages) is accepted for critical lifetime.

3 Results The obtained critical lifetime of the engineering structure is compared with the normative service determined by the technical documents. The calculated critical lifetime may be less than (I) or greater than the normative service lifetime (II). In case of exceeding the normative service lifetime over the critical (I), it is recommended to conduct a technical inspection of the object order to make a decision on further operation. Vilches et al. [11] in work also offer a life cycle methodology as a tool for the reconstruction of buildings and structures. Other authors [12] estimate the durability and cost of increasing the life cycle of transport facilities. As a rule, the critical lifetime of the object, according to the literature, exceeds the normative (II). When exploitation period of object approaching to the critical lifetime is recommended to take additional measures. Next, the strength reserve is determined as the difference between the critical and normative service lifetime.

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Now, many engineering constructions come nearer to normative service lifetime. For example, authors [13] predict the loss of bearing capacity of structures by 2050.

4 Conclusion Thus, the authors propose a methodological approach to assess the critical lifetime of engineering structures in cold regions. The practical significance of the work lies is possibility of using the methodology proposed by the authors, by both the state supervisory bodies and educational institutions within the carrying out research. In the future, it is planned to test the proposed approach on real objects. Acknowledgements The presented research was financially supported by the Russian Science Foundation (grant no. 17-77-30006).

References 1. Kronik YA (2010) Anti-theft soil stabilization to improve the reliability and security of the buildings and constructions. Vestn MGSU 4(2):284–290 2. Sato T, Sutoh A, Maruyama O, Kanekiyo HT (2017) Deterioration situation of road infrastructure (bridge and tunnel) in cold region. In: Life-cycle of engineering systems: emphasis on sustainable civil infrastructure. Taylor & Francis Group, London, pp 2247–2255 3. Niu FJ, Liu MH, Cheng GD, Lin ZJ, Luo J, Yin GA (2015) Long-term thermal regimes of the Qinghai-Tibet Railway embankments in plateau permafrost regions. Sci China Earth Sci 58(9):1669–1676 4. Lepage JM, Doré G (2016) Experimentation of mitigation techniques to reduce the effects of permafrost degradation on transportation infrastructures at Beaver Creek experimental road site (Alaska Highway, Yukon). Doctoral dissertation, Université Laval 5. Grebenets VI, Isakov VA (2016) Deformation and stabilization of motor and rail roads within the Norilsk-Talnakh transportation corridor. Kriosfera Zemli 2:62–68 6. Vimal K, Gurumurthy A (2017) Modelling and analysis of sustainable manufacturing system using a digraph-based approach. Int J Sustain Eng 1–15 7. Gothwal S, Raj T (2016) Performance evaluation of flexible manufacturing system using digraph and matrix/GTA approach. Int J Manuf Technol Manage 30(3–4):253–276 8. Titova T, Akhtyamov R, Nasyrova E (2017) Wear degree assessment of low-pressure earth dams within urban landscape. Procedia Eng 189:215–220 9. Afanasev I, Volkova T, Elizaryev A, Longobardi A (2014) Analysis of interpolation methods to map the long-term annual precipitation spatial variability for the republic of Bashkortostan, Russian Federation. WSEAS Trans Environ Dev 10:405–416 10. Titova T, Akhtyamov R, Nasyrova E, Longobardi A (2017) Lifetime of earth dams. Mag Civ Eng 1(69):34–43 11. Vilches A, Garcia-Martinez A, Sanchez-Montañes B (2017) Life cycle assessment (LCA) of building refurbishment: a literature review. Energy Build 135:286–301 12. Ugwua OO, Kumaraswamya MM, Kungb F, Nga ST (2005) Object-oriented framework for durability assessment and life cycle costing of highway bridges. Autom Constr 14(5):611–635 13. Hjort J, Karjalainen O, Aalto J, Westermann S, Romanovsky VE, Nelson FE, Etzelmüller B, Luoto M (2018) Degrading permafrost puts Arctic infrastructure at risk by mid-century. Nat Commun 9:5147

The Determination of Soil Cutting Force Applied with Bucketless Bottom Rotor with Account of Speed and Runout Serik N. Nurakov , T. Awwad , A. Kaliyev

and A. S. Tulebekova

Abstract The advantages of throwing machine with bucketless bottom unloading rotor (BBUR) for application in transport construction have been given. The rotor runs from up to down toward the bottom and has high speed, carries out cutting significant force which allows working out firm soil. And a built-in thrower in the rotor picks loose earth up and throws it away for a long distance. The calculation procedure of rotational component for BBUR has been suggested based on previous received calculated formula for a process of cutting soil with pointed tooth of sideway cutting, where the influence of cutting speed and teeth runout with extra kinetic factor in the excavation process are taken into account. Keywords Bucketless rotor · Bottom unloading · Rotor thrower · Sideway cutting tooth · Runout · Cutting speed

1 Introduction The huge volumes of earthwork in the transport construction are carried out at the present time, which are done in the most difficult mining-and-geological, soil and temperature climatic conditions where new effective machines are required. Significant amounts of work are performed in the areas of seasonal freezing of soils, despite the difficulties of their development. For example, opening, tearing out pits, trenches, channels, holes, creating wells, etc. Various machines and technical equipment are available and continue to be improved and working bodies for their use. Mechanical methods of destruction of frozen soils are more useful although they are very energy-intensive. Watch them should be particularly noted way to develop S. N. Nurakov · A. Kaliyev · A. S. Tulebekova L.N. Gumilyov, Eurasian National University, Astana, Kazakhstan T. Awwad (B) Emperor Alexander I St. Petersburg State Transport University, St. Petersburg, Russia e-mail: [email protected] Damascus University, Damascus, Syria © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_50

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cutting. Despite the intensive development of this area, its main problem is high energy intensity and dynamic workflow. Among the new developments in this direction should be highlighted research and the creation of the most effective cutting elements of oblique cutting of various designs for rotary working bodies. The problem of cutting of freezing soil ground has been studied by many scientists like Bakakin V. P., Zelenin A. N., Vakhidov U. Sh., Alimov O. D., Khmara L. A., Tarasov V. N., Ryu B. N., Bahr J., Gartner K., Pasper I., Karlov V. D. and et al. [1–10].

2 The Bucketless Bottom Unloading Rotor (BBUR) One of such kind of machines is a working attachment as a rotor thrower for layer soil excavation which allows excavating hard soil ground and it can work at a high speed and can be used in ground laying in inaccessible places in the process of excavation, fill formation, etc. The bucketless bottom unloading rotor (BBUR) with sideway cutting elements and built-in thrower complies with the requirements. The average component values for cutting force on a rotor thrower equipped with the full set of teeth Z z , may be determined with consideration of previously extracted dependences for a single cutting element with account of speed and runout. Accordingly, the average value of the cutting force tangential within the rotor’s one turn may be disclosed if the unfolded form:

(1)

where β 1 cutting angle, degrees; Z z number of teeth on a rotor, pcs. In a similar way, the average value for the cutting force end component will depend on the chippings variable thickness ai = a0 sinβ i :

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481

(2)

In the same manner, we derive an expression for the cutting force normal component: (3)

Based on the abovementioned dependence related to the tangential force on a rotor (1) the formulae recommended by Dr. of Tech. Sc. Volkov D. P., may be used to calculate dynamical load (tangential force and torque moment on a rotor) over the rotor thrower and excavator’s metalwork elements [11]: k

V Pmax = PkV( mid) +

−

γ =1

2 PkV(mid) ( K D − 1)

γπ

cos γπ sin γω t

and

(4) k

V M max = M cV +

− γ =1

2 M kV(mid) ( K D − 1)

γπ

cos γπ sin γω t ,

where V Pmax

maximum values for the tangential force with account of speed effect, kN; maximum values for the torque moment on the rotor axis with account of speed effect, kN m;

V Mmax

ω

t KD γ κ

=

π Zn p 30

external load periodic variation’s frequency (frequency of teeth facing the bench), c−1 ; time, s; coefficient of rotor’s digging tangential force dynamics, determined by experiment; coefficient, indicating the number of composed Fourier’s series; number of Fourier’s series components, providing acceptable accuracy of the external load approximation, usually does not exceed κ = 3–4.

The analysis of the above derived formulae for calculation of the tangential, end and normal forces on the thrower rotor (1, 2, 3) indicates to the forces contributing to reduce the cutting resistance of the soil under chippings separation by the least energy-consuming diagonal semi-free cutting with the BBUR cutting element shaped as a deteriorated diagonal wedge performing a complex movement; improve the BBUR’s work stability and explain the best dynamic properties compared to the rotors of other design. We will consider the features of BBUR cutting force components.

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Thus, the particular importance is given to the direction of the tangential component of the resistance force Rnx “bottom-upwards”, which unloads the thrower’s running gear and influences on the coupling and traction properties of the unit. Besides, it has been determined that the dynamic effect of this force is connected to the frequency of the teeth facing the bench and the impact effect when the teeth face the bench, that is significantly reduced due to the design of diagonal wedge and simultaneously is extinguished by significantly greater mass of the machine and does not cause its oscillations. The damping of possible vertical oscillations is also contributed by the friction force on the tooth rear edge which is constantly in contact with the bench surface (ψ = 0). Such complex influence contributes to increase the effectiveness of rotor excavator’s work member under working on the firm grounds. Also, the dependences were derived for the first time to determine the end and normal cutting forces with account of the speed and runout, so as they were previously admitted as parts of the tangential force, and did not reveal the influence of cutting speed and tooth runout for their formation. Besides, a very important new identified factor is the presence and influence of “tightening” components of the forces Rny and Rnz , which contribute to the stable operation of the work member and reduce energy costs for the end feed. The calculation shows that load dynamics and oscillations of diagonal multistage cutting rotor under practically applied speeds up to 5–9 m/s will be minimal and will not significantly affect the rotor’s operation and the machine altogether.

3 Features of Determination of the Soil Cutting Force Further, we may proceed to the determination of the soil cutting force by diagonal multistage cutting bucketless rotor thrower with account to the speed. The cutting force by the bucketless bottom unloading rotor PpV consists of the V wit account to the speed factor and clean cutting force (chippings extractions) Pmid additional force Pd.p. to impart the kinetic energy of the chippings extracted from the soil massive by the cutting elements from the moment of cutting until its extraction from the tooth surface and transition to the thrower’s blades. Thence the rotor’s cutting force may be written down as follows: (5) V is determined in accordance with the above-derived where the clean cutting force Pmid dependence (1). The additional force Pd.p. for chippings acceleration on a single tooth may be derived from the following assumptions (Fig. 1). The chippings movement along the tooth surface may be divided into two periods. During the first period after splitting the chippings element extracts from the soil massive and immediately reaches the tooth front edge where it attains the speed

The Determination of Soil Cutting Force Applied with …

483

Fig. 1 Forces scheme on the diagonal multistage cutting rotor’s teeth

equal to the speed of the rotor’s cutting edges V p , but moves along the tooth surface oppositely to the rotor rotation being pushed from behind by the next chippings element split from the massive after the previous one. The considered chippings element slides along the tooth surface, suffering, besides the pushing force, braking effect from the friction force against the tooth metal. Next elements being extracted, the movement of the considered chippings continues, but under gradual speeding down. At a given period of time, under the friction, weight and the ceasing pushing forces of following elements the chippings stop due to their loosening, the relative speed equals to zero, but at the same time it attains the speed of the tooth and changes its direction to the opposite, turning with the rotor under-speed V p [12]. For the considered case we use a theorem related to movement quantity changes in a shape of a theorem related to the amount of impulses relating to one second volume of chippings: 1 Q − Q1 =

Fdt = F · 1c, 0

where

(6)

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Q − Q 1 changing of movement quantity, kN s; F force, N. We get from the formula (6): F = Q − Q0 = mc V − mc V 0,

(7)

where mc one second chippings mass, kg; V 0 and V chippings initial and final speed on the tooth, m/s. By projecting an Eq. (7) on the direction of the tangential cutting force and thus neglecting the angle of chippings elevation along the front surface of the tooth, equal to the cutting angle αp, we may write down: Fk = m c V0 − (−mV ) + m c V0 + m c V.

(8)

Since the initial V 0 and final speeds of the chippings are equal to the rotor speed V p , we obtain Fk = 2m c V p .

(9)

Consequently, the additional force Pdp. , consumed in the process of cutting by the tooth to impart kinetic energy of the chippings during its presence on the front surface, will be equal to: (10) Thence the cutting force may be written down with account of formula single tooth and additional force Pdp (10):

for a

(11)

4 Conclusions Thereby, the derived dependence considers the speed and runout influence not only to the clean cutting process but considers the speed influence on the chippings acceleration along the tooth surface as well. The suggested methodology of calculating

The Determination of Soil Cutting Force Applied with …

485

the additional component shows its value is twice higher than the value of the kinetic energy, calculated by the well-known formula: (12) In order to determine digging force by a rotor with a full set of teeth within one full turn, the one-second quantity of chippings qc is found by using the methodology of Dr. of Tech. Sc., Professor Serik N. Nurakov [13–16]: (13) where V n rotor’s end feed speed, m/s; γ ob soil bulk weight, kg/m3 . Within a tooth one turn from β 1 to π (Fig. 1) the formula appears as: (14) Thence the additional force to accelerate the chippings along the cutting elements surface within the rotor’s full turn will become: (15) where Z z number of teeth on the rotor’s shell, pcs. Consequently, the common formula (5) to calculate the digging force by bucketless bottom unloading rotor for diagonal multistage cutting may be written down with account to the additional kinetic component Pd.p. (15) and dependence (1) for in the unfolded form [13–15]: tangential force considering speed and runout

(16)

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Thus the methodology which considers the cutting speed and the teeth runout effects with account to the additional kinetic component during the digging process has been suggested to calculate the tangential component for the BBUR.

References 1. Bakakin VP, Zelenin AN (1963) Development of frozen soils. In: Reports at the international permafrost conference, Moscow, pp 145–156 2. Vahidov USh (2014) Machines for the development of ice, snow and frozen ground Nizhny Novgorod, Published by NSTU. p 175 3. Alimov OD (1963) Machines for cutting frozen ground with chain tools. J Tomsk Polytech Inst 4. Khmara LA, Dakhno OA (2017) Optimization of the process of digging a single-bucket excavator with a telescopic working equipment. Constr Road Build Mach 4:12–21 5. Tarasov VN, Boyarkina IV (2017) Justification of the tables of specific energy intensity of the process of digging of soils with an excavator bucket backhoe. Constr Road Build Mach 1:7–12 6. Ryu BN (2014) Deformation characteristics of the water supply pipelines during ground freezing factors and behavior. Ph.D. thesis, Incheon National University, South Korea 7. Bahr J, Freiberg (1965) Die dynamische Krafte Beim Abtragen schweren Bodens mit Schaufelradbaggern. Bergbautechnik 5:270–287 8. Gartner K (1956) Schaufelradbagger als Baugerat. Fordern und Heben 6:56–64 9. Pasper I, Schokz K (1969) Bemerkenswert Kontinuirlich arbeitendes Ezdbaugerat fur den Chasma Ihelum Link Kanal, pp 1–10 10. Karlov VD (2007) Foundations on seasonally frozen heaving soils. St. Petersburg, p 362 11. Volkov DP, Cherkasov VA (1969) Dynamics and strength of multi-bucket excavators and stackers. Moscow, p 449 12. Awwad T, Mussabayev T, Tulebekova A, Jumabayev A (2019) Development of the computer program of calculation of concrete bored piles in soil ground of Astana city. Int J GEOMATE 17(60):176–182 13. Nurakov S, Awwad T (2019) Investigation on soil cutting by non-bucket bottom rotor end chisels. Int J GEOMATE 16(53):231–237 14. Awwad T, Gruzin A, Gruzin V (2019) Upgrading of the technologies of soil preparation and construction of foundations for structures of oil and gas industry. In: Shehata H, Das B (eds) Advanced research on shallow foundations. GeoMEast 2018. Sustainable civil infrastructures. Springer, Cham, pp 220–227 15. Nurakov S, Awwad T (2019) The frozen grounds processing with a bucketless bottom rotor, selected issues. In: MATEC web of conferences, vol 265, p 04006 16. Awwad T, Gruzin V, Kim V (2019) Sustainable reconstruction in conditions of dense urban development. In: Weng MC, Lee J, Liu Y (eds) Current geotechnical engineering aspects of civil infrastructures. GeoChina 2018. Sustainable civil infrastructures. Springer, Cham, pp 13–23

Analysis of the Settlement of New Construction Drill-Injection Pile with Broadening at the End in Silty-Clayed Soils Mikhail Samokhvalov , Andrei Geidt and Aleksandr Paronko

Abstract The article presents a new «soft-injection» technology of the foundation strengthening in silty-clayed soils. This technology is based on re-design drillinginjection pile producing with using a metal pipe and the rubber membrane cup at the end. When mortar is injected, the membrane increases in size (stretches) in the soil massif and widens to the predicted diameter on the lower end. This article contains the algorithm for determining the nonlinear settlement of drilling-injection pile in clay soils under static loading and the method of calculations settlement broadening at the end of pile. According results of the pilot study to present graphics showing susceptibility settlement of building from loading. Also given comparative analysis this data with calculated and regulatory values. On the basis of the analysis of the results of field tests and the existing methods for the prediction of interaction of the formed body of the pile with soil, we compute the principal design-basis parameters. We propose an algorithm for the evaluation of settlement of the drillinjection pile with controlled broadening taking into account both the variations of the characteristics of the compacted zone of soil near the pile and the influence of residual stresses. Keywords Drilling-injection piles (micropiles) · Controlled broadening at the end of pile · Dusty-clay soils

1 Introduction There are a significant number of foundations of buildings in need of renovation. The purpose of these researches is to ensure the development of underground space. Additional underground space can be used for locating engineering networks and transport infrastructure. From technical point of view, foundations of buildings are main structures to ensure the normal service building and its durability. Invention M. Samokhvalov (B) · A. Geidt · A. Paronko Industrial University of Tyumen, St. Volodarsky 38, Tyumen 625000, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_51

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Fig. 1 Schematic illustration of drill-injection pile installation with the controlled broadening: 1— borehole, 2—injector tube, 3—clamp, 4—membrane cup, 5—rubber sleeves, 6—hose, 7—packer, 8—concrete plug, 9—compressed zone of soil massif

of a new technology for reinforcement foundations of buildings is a topic of considerable relevance. Solution of the problem is complicated by two factors. The first is related to the implementation of works in the cramped conditions of the central part of the existing urban development. Second is related to soil conditions represented mainly by weak silty-clay soils. The search for possible solutions has shown that good technologies are the most “soft” technologies (micropiles: «gewi», «titan inchebeck», «TK-ASF» «MAI», etc.). These technologies make it possible to perform work without shock, mechanical, and dynamic effects. This is very important for cultural heritage buildings. The “soft” technology is the upgraded design of the drill-injection pile. It consists of a metal tube that performs the function of injection, and controlled broadcasting on pile end, formed in the process of injection of the cement mortar (Fig. 1). Results of experimental studies have given construction pile details presented in articles [1, 2]. For the industrial implementation of this design, it is necessary to develop an algorithm for determining its settlement in silty-clayed soils.

2 Initial Data for Calculations Performed engineering and geological surveys at a construction playground in the city of Tyumen made it possible to determine the following characteristics of clay soil (Table 1).

Analysis of the Settlement of New Construction Drill-Injection … Table 1 Physico-mechanical characteristics of clay soil

489

Parameters

For soil beyond broadening

For soil around the pile shaft

z, m

3.0

0–2

2–3

γ,

kN/m3

19.1

17.8

19.1

W

0.3

0.18

0.3

Sr

0.91

0.65

0.91

e

0.76

0.81

0.76

IL

0.63

0.16

0.63

ν

0.34

0.31

0.34

ϕ, degree

17.1

18.0

17.1

c, kPa

21.1

26.1

21.3

G, MPa

4.8

4.8

5.0

E com , MPa

2.4 (7.8)

3.3 (18.7)

2.4 (7.8)

E, MPa

2.9

3.2

2.9

E 50 , MPa

6.1

5.9

6.1

K, MPa

12.8

12.4

12.6

Note Brackets show the value of the modulus of deformation of soil E com , corrected by multiplying by the factor moed , accepted according to requirements SP 22.13330

3 Determination of Nonlinear Settlement of Drilling-Injection Piles at Static Loading In order to evaluate the feasibility using of the drill-injection pile with controlled broadening on the lower pile end in clayed soil under static loading need to learn how to correctly predict change strain-stress state ground mass under the foundation building in determining his settlement. The settlement of the structure value depends on the estimated resistance of the basement soil modified in the process of the producing drill-injection pile, both on the lateral surface and under the lower end.

3.1 Settlement of Controlled Broadening Elastic-plastic model [3–7] allows you to determine the sediment caused by the movement of the soil to the sides of the boundary of the compacted core around the controlled broadening, radius Rcom1 by the formula (1): 

τ∗

γ (r ) = τ G(r ) · τ ∗ −τ1 (r ) , ) γ (r ) = − ds(r dr

(1)

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where γ (r) (m)—angular deformation; G (kPa)—shear modulus of soil (p.7.4.2 SP 24.13330 formula 2); τ (r) (kPa)—shear stress in the soil from the pressing load N (formula 3); τ *1 (kPa)—limit value shear stress (formula 4); and s(r) (m)—settlement of controlled broadening. E , 2 · (1 + ν)

G=

(2)

where E (MPa)—modulus of deformation and ν—Poisson ratio. τ (r ) = τu1 ·

(rc + u 1 ) , r

(3)

where τ u1 (kPa)—shear stresses arising at the boundary of the broadening contour and the soil (formula 5); r c —initial borehole radius which is adopted depending on the diameter of the screw drilling equipment, r c = 0.04 m; and u1 —radial displacement of the wall of the membrane cup, m. τ1∗

= γcR · Rbro

     1 + sin ϕ cos ϕ com + 2 · Ccom1 · , = γcR · σr · 1 − sin ϕ 1 − sin ϕ

(4)

where γ cR = 1.3—factor of working conditions of the soil massif under broadening (SP 24.13330); Ryx —the value of the estimated resistance of the basement soil in the zone of formation of controlled broadening; σ com r1 (kPa)—radial stress (formula 6); ϕ—the average value of the angle of internal friction of the soil, in the zone of formation of controlled broadening, an assumption is introduced that the value of the internal angle of friction is constant; and C com1 (kPa)—intercept cohesion in the formation zone of broadening. This parameter changes from a change in void ratio in the process of soil compaction during the formation of controlled broadening (formula 7). N π · (rc + u 1 )2

(5)

σr1com = plim 1 + σ01 ,

(6)

τu1 =

where plim1 (kPa)—critical pressure (formula 8); σ 01 —horizontal active lateral pressure of soil (formula 9). ecom1 =

kw1 · W0 · ρs , Sr · ρw

(7)

where k w1 —factor taking into account the change in the initial soil water content (W 0 ) in the consolidation zone (Rcom1 ). ρ s (g/cm3 )—density of soil solid particles; S r (d.e.)—saturation ratio; and ρ w = 1 g/cm3 —distilled water density.

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4 · (σ0 · sin ϕ0 + c · cos ϕ0 ) (1 − w − sin ϕ0 (3 + w))   ν + γ p · z 2 · γ p · z · 1−ν (2 · σh + σz ) = = 3 3 plim 1 =

σ01

(8) (9)

The solution of the system of Eq. (1) leads to the expression: s(r ) = −

τu · τ ∗ G

=−

  τ∗ ·

dr r (rc +u 1 )

− τu



  τ∗ τu · (rc + u 1 ) · ln · r − τu + D, G (rc + u 1 )

(10)

D—constant of integration, which should be determined from the boundary conditions of the solution of task:   τ∗ τu · (rc + u 1 ) (11) · ln · Rcom1 − τu s(r = Rcom1 ) = 0 ⇒ D = G (rc + u 1 ) To get the final expression to determine the precipitation broadening, substitute value D formula (11) and value τ u1 formula (5) in the expression (10):  N s1 = · ln π · G · (rc + u 1 )

τ∗ (rc +u 1 )



· Rcom1 −

τ∗ −

N π·(rc +u 1 )2

N π·(rc +u 1 )2





(12)

Graphs of the settlement are from the load s = f (p), built on the results of experimental data, and calculations according to the proposed methodology and regulatory requirements are shown in Figs. 2 and 3. On the graph in Figs. 2 and 3, line No. 2 has the greatest convergence with experimental values. The difference of the line of dependence s = f (p) No. 2 from No. 3 is in changing the summand (characterizing the stress-strain state of a consolidation soil massif within the formed broadening) in formula (12):  s1 =

N · ln π · G com1 · (rc + u 1 )

∗ τcom1 (rc +u 1 )

· Rcom1 −

 τ∗ −

N π·(rc +u 1 )2

N π·(rc +u 1 )2



(13)

1. G is replaced by Gcom (formula 2) with change the value deformation modulus E com1 , which can be defined by known methods [8–14]; 2. τ *1 changing to τ *com1 (formula 4) with a change in the value of radial stresses and taking into account residual internal stresses, remaining in the soil massif after the formation of a controlled broadening at the end of the pile [15–17]:

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Fig. 2 Settlement-load comparative diagrams s = f (p) for drill-injection piles with the controlled broadening cubic capacity 30 l

(14) Settlement of a broadening can be determined by the requirements of regulatory documents (p.7.4.2 SP 24.13330): sbro =

0.22 · N G com · 2 · (rc + u 1 )

(15)

3.2 The Sediment of the Pile Shaft For the calculation settlement of the pile shaft (without the influence of controlled broadening at the end of the pile and hydraulic fractures along its trunk), write the expression when r = (r c + u2 ):

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493

Fig. 3 Settlement-load comparative diagrams s = f (p) for drill-injection piles with the controlled broadening cubic capacity 40 l

 τu2 · (rc + u 2 ) · ln s= G

· Rcom2 − τu2  ∗  , τ2 − τu2

f lat (rc +u 2 )

(16)

where u2 (m)—radial displacement of the inner surface of the well during the formation of the pile shaft, (formulae 17–18); Rcom2 (m)—radius of soil compaction zone along the pile shaft (formula 19); f lat , (kPa)—the calculated value of soil resistance on the lateral surface of the pile shaft (formula 20); and τ u2 —shearing stresses from the pressing load (formula 21). u 2 = ( pin2 − σ0 ) · (A21 + ·A22 · (1 + w)) ·

1 E

1−α+β

u2 =

(17) 1+β

1 − kr2 1 1 − kr2 1 1 β · A · plim2 · kr2 + · M · − ·N· E E 1+β −α E 1+β

(18)

Rcom2 = (rc + u 2 ) · kr2

(19)

  τ2∗ = f lat · γcf = γcf · σr2com · tgϕ + Ccom ,

(20)

where γ cf —condition load effect factor (γ cf = 0.7 p.7.6 SP 24.13330); σ com r2 (kPa)— radial compression of the soil mass, [18–24] (formula 22); C com2 , (kPa)—specific

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cohesion, determined by substituting the value airspace ratio compacted soil on the lateral surface of the pile shaft ecom2 , and factor’s k w2 = 0.8, taking into account the reduction of moisture on the pile shaft (on average 20%); τu2 =

N 2 · π · (rc + u 2 ) · l

(21)

where l—length of drill-injection pile, m. (22) where plimp2 , (kPa)—critical pressure on the inner surface of the well wall (formula 23) and σ 02 —the lateral pressure of soil (formula 24). plim =

−2(σ0 · sin ϕ0 + c · cos ϕ0 ) (w + 2) sin ϕ + w

(23)

σ02 = γsoil · z · ν/(1 − ν)

(24)

Thus, substituting in the formula (16) the value τu2 of the formula (21), we write the final expression to calculate the piles shaft:  N s= · ln 2·π ·l ·G

τ2∗ (rc +u 2 )



· Rcom2 −

τ2∗ −

N 2·π·(rc +u 2 )·l

N 2·π·(rc +u 2 )·l



(25)

The settlement of the pile shaft can be determined according to the requirements of regulatory documents (p.7.4.2 and the application D SP 24.13330):  s1 = 0.17 · ln

kν · G 1 · l G2 · d

 ·

N G1 · l

(26)

G1 (kPa)—modulus of shearing soils in the area of widening, G2 (kPa)—modulus of shearing soils on the pile shaft; and k ν —factor depending on the average value of the transverse deformation factor: kν = 2.82 − 3.78 · ν + 2.18 · ν 2

(27)

A comparison of the values of the pile shaft settlement according to the proposed method and regulatory requirements is shown in Fig. 4.

Analysis of the Settlement of New Construction Drill-Injection …

495

Fig. 4 Settlement-load comparative diagrams s = f (p) for drill-injection piles without the controlled broadening

3.3 Determination of Settlement of Drilling-Injection Piles To determine the settlement of the drilling-injection piles with controlled broadening, combine the following formulas (12) and (25):

s=

N · ln π · (rc + u 1 ) · G 1 + 2 · π · l · G 2

where τu =

  com1 τ ∗ · rRc +u + 1

Rcom2 rc +u 2

(τ ∗ − τu )



− τu

(28)

N . π·(rc +u 1 )2 +2·π·l·(rc +u 2 )

       com 1 + sin ϕ cos ϕ end + 2 · Ccom · · + τ2 = γcR · σr + σr τ = 1 − sin ϕ 1 − sin ϕ   com (29) + γcf · σr2 · tgϕ + Ccom ∗

∗ τcom1

Settlement of the drill-injection pile can be determined according to the requirements of regulatory documents (p.7.4.2 and application D SP 24.13330):

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sc =

kν · G 2 · l N · 0.17 · ln G2 · l G1 · d

(30)

4 Conclusion According to the results of numerical calculations carried out by the formula (28) and according to the technique described in SP 24.13330, it is possible to determine with a significant margin the settlement of the drilling-injection pile with controlled broadening. To more accurately determine the settlement value by the formula (28), the following parameters must be taken into account: residual stresses and changes in mechanical characteristics in the formation of a compacted soil zone.

References 1. Samokhvalov MA, Geidt AV, Paronko AA (2018) Results of the calculated prediction for interaction of drilling-injection piles, having controlled broadening, with dust-clay ground basis. 9:484–496 2. Samoxvalov M, Zazulya Y, Kajgorodov M (2017) Results of a study of stress-strain state of the soil massive around the resulting broadening at the end drill-injection pile. Russ J Build Constr Archit M 36:50–57 3. Gotman AL, Gotman NZ (2011) Strengthening of the foundations of a building under construction at a commercial complex in ufa. Soil Mech Found Eng 48:2–7. https://doi.org/10. 1007/s11204-011-9134-8 4. Polishchuk AI, Maksimov FA (2018) Engineering method of calculating the settlement of twobladed screw pile in clayey soil. Soil Mech Found Eng 54:377–383. https://doi.org/10.1007/ s11204-018-9484-6 5. Ter-Martirosyan Z, Sidorov V (2018) Settlement and bearing capacity of the circular foundation. In: MATEC web conference, vol 196, p 03019 (2018). https://doi.org/10.1051/matecconf/ 201819603019 6. Bakholdin BV, Yastrebov PI, Parfenov EA (2007) Peculiarities in settlement calculations for foundations formed from cast-in-place piles. Soil Mech Found Eng 44(6):199–204. https://doi. org/10.1007/s11204-007-0037-7 7. Polishchuk AI (2000) Assignment of the design resistance of bed soils for foundation of buildings to reconstruction. Soil Mech Found Eng 37(3):71–77 8. Il’ichev VA, Mangushev RA, Nikiforova NS (2012) Development of underground space in large Russian cities. Soil Mech Found Eng 49(2):63–67. https://doi.org/10.1007/s11204-0129168-6 9. Osama FEHD, El Naggar MH (2014) Axial monotonic and cyclic compression behaviour of hollow-bar micropiles. Can Geotech J 52:426–441. https://doi.org/10.1139/cgj-2014-0052 10. Polishchuk AI, Tarasov AA (2017) CFA pile carrying capacity determination in weak clay soils for renovated-building foundations. Soil Mech Found Eng 38–44. https://doi.org/10.1007/ s11204-017-9430-z 11. Alnuaim AM, El Naggar MH, El Naggar H (2015) Performance of micropiled raft in clay subjected to vertical concentrated load: centrifuge modeling. Can Geotech J 52:2017–2029. https://doi.org/10.1139/cgj-2014-0448

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12. Stepanov M, Melnikov R, Zazulya J, Ashihmin O (2017) Generation of stress-strain state in combined strip pile foundation beds through pressing of soil. In: MATEC web conference, p 02011, 1–8 13. Polishchuk AI, Maksimov FA (2016) Improving the design of screw piles for temporary building foundations. Soil Mech Found Eng 53:282–285. https://doi.org/10.1007/s11204-0169399-z 14. Valeri E, Richter E (2005) Electrical discharge (explosions) in geotechnical engineering. In: ˇ Vaniˇcek I et al (eds) XIII ECSMGE, CGtS, Prague, Session 4 «Foundations in urban areas», pp 413–418 15. Hakam A, Asmirza MS, Andriani HP (2018) Additional bearing capacity of piles due to time delay of injection. Int J GEOMATE 15:151–157. https://doi.org/10.1002/fld.1650100605 16. Rybicki J, Atefi-Monfared K (2018) A novel numerical study of reservoir-induced subsidence and upheaval effects on bearing capacity of offshore piles. Geotechnical Special Publications, 2018 Mar, pp 242–251. https://doi.org/10.1061/9780784481578.025 17. Georgiadis K, Georgiadis M, Anagnostopoulos C (2013) Lateral bearing capacity of rigid piles near clay slopes. Soils Found 53(1):144–154. https://doi.org/10.1016/j.sandf.2012.12.010 18. Mangushev RA, Konyushkov VV, D’yakonov IP (2014) Analysis of practical application of screw-in cast piles. Soil Mech Found Eng 51:227–233 (2014). https://doi.org/10.1007/s11204014-9281-9 19. Kam N, Seidman J, Lim RM (2018) Examining auger cast-in-place piles in difficult ground conditions. In: IFCEE 2018, pp 428–439 20. Ma L, Wang Y, Wang W, Xu X, Li S (2017) An analysis method for nearshore laterally loaded rigid pile in cohesive soil. Mar Georesour Geotechnol 0618. https://doi.org/10.1080/1064119x. 2016.1255689 21. Sun L, Wang Y, Guo W, Yan S, Chu J, Liu X (2017) Case study on pile running during the driving process of large-diameter pipe piles. Mar Georesour Geotechnol 0:1–13. https://doi. org/10.1080/1064119x.2017.1386742 22. Gabrielaitis L, Papinigis V, Sirvydait˙e J (2012) Assessment of different methods for designing bored piles/Skirting˛u Metod˛u Vertinimas Projektuojant Gr˛ežtinius Pamatus. Eng Struct Technol 4:7–15. https://doi.org/10.3846/2029882x.2012.676326 23. Gabrielaitis L, Papinigis V, Žaržojus G (2013) Estimation of settlements of bored piles foundation. Procedia Eng 24. Bayesteh H, Sabermahani M (2018) Full-scale field study on effect of grouting methods on bond strength of hollow-bar micropiles. J Geotech Geoenviron Eng 144:04018091. https://doi. org/10.1061/(asce)gt.1943-5606.0001983

Numerical Analysis Using Elastic–Plastic Soil Model for a Single Pile in Clay Layer to Examine the Effect Surcharge Loading on the Distribution of Skin Friction T. Awwad , S. Al Kodsi , V. Ulitsky, A. Shashkin and L. Awwad

Abstract Loading the ground surface next to the pile head is the main reason for the soil layers’ settlements. According to the relative movement between the pile and soil, skin friction along the pile’s shaft is distributing. In this paper, a numerical modeling will be carried out using finite elements technique to examine the pilesoil loading combination on the distribution of skin friction. The model is elastic– plastic relationship between stress and strain and is first validated by comparing the numerical results with the ones obtained from a full-scale loading field test. A parametric study will be conducted herein using different cases of loading on both pile and the ground surface. The value of the surcharge load and the type of loading will be discussed and their effect on the location of neutral plane; point of equilibrium will be examined. Keywords Neutral plane · Skin friction · Single pile · Parametric study · Elastic–plastic model

1 Introduction Pile foundations are traditional form of foundations in bad subsoil conditions. Friction pile is usually installed in a compressible soil layer beyond the reach of any incompressible bearing strata at its tip, thus it transmits the loads to the surrounding soil mainly through the pile’s shaft. A relative movement between pile and the soil T. Awwad (B) Damascus University, Damascus, Syria e-mail: [email protected] S. Al Kodsi Osaka University, Osaka, Japan T. Awwad · V. Ulitsky · A. Shashkin Emperor Alexander I St. Petersburg State Transport University, St. Petersburg, Russia L. Awwad Saint Petersburg State University of Architecture and Civil Engineering, St. Petersburg, Russia © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_52

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leads to mobilize shear stresses along the interface between pile and adjacent soil. Moreover, the excessive settlement associated with the down drag can cause vital damages to the superstructure of a building [1]. Terzaghi and Peck [2] assumed full mobilization of shear strength along the pile-soil interface up to the pile toe for a single pile, or along the perimeter of pile group. Therefore, the neutral point (point of zero shear stress) is assumed to be located at the bearing stratum of the pile. Indraratna et al. [3] suggested that in order to minimize the negative skin friction, piles may be driven few weeks, or a month later after the surcharge load is applied on the ground surface. Poorooshasb et al. [4] studied the case of a single pile of circular cross-section considering an axisymmetric problem with a surcharge pressure on the underlying clay layers. Hanna and Sharif [5] conducted a study on piles driven into clay and subjected to indirect loading through the surcharge applied symmetrically on the surrounding area. The study was based on a numerical model using finite element technique and the soil was assumed to follow a linear elastic-perfectly plastic stress–strain relationship, which defined by Mohr–Coulomb failure criterion. The objective of this paper is to study the factors affecting the distribution of NSF along the pile length besides the examination of the access of pore water pressure and the change in NPL. Field tests of a single pile in clay layers will be presented herein to compare the field measurements with the analytical modeling.

2 Model Validation 2.1 Soil Constitutive Model The soil was modeled to behave as a linear elastic-perfect plastic material, and its yield function is defined by Mohr–Coulomb criterion. The model is used usually because of its reasonable accuracy, simplicity and widely used in practice. The basic parameters required for the elastic perfectly plastic model includes Modulus of elasticity (E), Poisson ratio (υ), Cohesion (c ), angle of internal friction (θ  ) and dilatancy angle (ψ) (Fig. 1). Fig. 1 Failure envelope of Mohr–Coulomb

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Table 1 Soil mechanical properties Soil type

Depth (m)

γ (kN/m3 )

E (MPa)

θ

C (kPa)

Clay

1.86

18.4

4.61

24.5

8.7

Mud clay

2.54

18.3

7.55

8.4

6.3

Clay

4.86

20.0

9.39

37.3

16.7

Silt

5.70

19.0

10.01

15.6

21.0

Silty clay

8.70

18.2

6.08

14.7

15.3

Silty sand

20.00

19.5

28.25

4.0

20.0

Table 2 Pile material properties Material

Length (m)

Diameter (mm)

γ (kN/m3 )

E (GPa)

Pile

1.86

18.4

4.61

24.5

Note υ = 0.3

2.2 Loading Test in Changsha, China Lu et al. [6] carried out a field test in Changsha city in China to investigate the negative skin friction. Groundwater level was at 0.6 m and a cast in place concrete pile was used with 43 m in length and 1 m in diameter. A (5 m) layer of embankment was constructed in the field test site. The mechanical properties for the soil profile are shown in Table 1. The properties of the pile material are shown in Table 2. The analytical model is shown in Fig. 2. A comparison between the field test measurements and the numerical model results for the skin friction distribution is shown in Fig. 3.

3 Study Model The study model is a driven concrete pile in two types of clay layers. The upper layer is a soft clay while the bearing is a stiff clay layer. Tables 3, 4, 5, 6, 7 and 8 show the soil and pile properties for the study model (after Azizul Hoque [7]).

4 Parametric Study The parametric study will be based on changing the surcharge load (Table 9). Surcharge Load (q) is the distribution load applied on the upper soil surface near to the pile which mobilize the negative skin friction along the pile length. Figure 4

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Fig. 2 Analytical model of the field test

shows the distribution of skin friction along the pile length and Fig. 5 shows the changing in the location of neutral plane versus the changing in surcharging.

5 Conclusion In this paper, finite element technique was used to carry on the parametric study to simulate the case of a single driven pile in clay layers. The ground surface next to the pile is under surcharging and according to the parametric study results, it can be concluded that the location of the neutral plane goes deeper when the surcharge load, increases. It is recommended not to overloading the ground surface next to the pile with a long term surcharging when the NSF is expected.

Numerical Analysis Using Elastic–Plastic Soil Model … Fig. 3 Comparison between field test measurements and analytical results

503

Skin fric on (Kpa) -25 -20 -15 -10 0

-5

0

5

10

15

-10

Depth (m)

-20

-30

-40

Field test

Numerical model

-50 Table 3 Properties of the clay used for Mohr–Coulomb (cohesion ratio 0.2)

Table 4 Properties of the clay used for Mohr–Coulomb (cohesion ratio 0.3)

Soil type γunsat

(kN/m3 )

Soft clay

Medium stiff clay

14

–

γsat (kN/m3 )

15.5

19

c (kPa)

10

50

φ

15

20

E (kPa)

5000

38,000 0.25

ν

0.2

k x (m/day)

8.0 × 10−4

4.0 × 10−4

k y (m/day)

8.0 ×

10−4

4.0 × 10−4

Soil type

Soft clay

Medium stiff clay

γunsat (kN/m3 )

14

–

γsat

(kN/m3 )

15.5

19

c (kPa)

15

50

φ

15

20

E (kPa)

6000

38,000

ν

0.2

0.25

k x (m/day)

7.5 × 10−4

4.0 × 10−4

k y (m/day)

10−4

4.0 × 10−4

7.5 ×

20

504 Table 5 Properties of the clay used for Mohr–Coulomb (cohesion ratio 0.4)

Table 6 Properties of the clay used for Mohr–Coulomb (cohesion ratio 0.5)

T. Awwad et al. Soil type

Soft clay

Medium stiff clay

γunsat

14.5

–

γsat (kN/m3 )

16

19

c

20

50

(kPa)

φ

15

20

E (kPa)

7000

38,000

ν

0.2

0.25

k x (m/day)

7 × 10−4

4.0 × 10−4

k y (m/day)

7×

10−4

4.0 × 10−4

Soil type

Soft clay

Medium stiff clay

γunsat (kN/m3 )

14.5

–

γsat

Table 7 Properties of the clay used for Mohr–Coulomb (cohesion ratio 0.6)

Table 8 Properties of the pile material

(kN/m3 )

(kN/m3 )

15.5

19

c (kPa)

25

50

φ

15

20

E (kPa)

8500

38,000

ν

0.2

0.25

k x (m/day)

6.5 × 10−4

4.0 × 10−4

k y (m/day)

6.5 ×

10−4

4.0 × 10−4

Soil type

Soft clay

γunsat

(kN/m3 )

Medium stiff clay

15

–

γsat (kN/m3 )

16.5

19

c (kPa)

30

50

φ

15

20

E (kPa)

10,000

38,000

ν

0.2

0.25

k x (m/day)

6.0 × 10−4

4.0 × 10−4

k y (m/day)

6.0 × 10−4

4.0 × 10−4

Material

Pile

Length (m)

30

Diameter (mm)

500

γ (kN/m3 )

24

E (kPa)

30,000,000

ν

0.3

Numerical Analysis Using Elastic–Plastic Soil Model … Table 9 Parametric study cases

Fig. 4 Distribution of negative skin friction along the pile

Fig. 5 Changing in the location of neutral plane versus the changing in surcharge load

505

Case

Value

Surcharge load (q)

14–112 kN/m2

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T. Awwad et al.

References 1. Brand EW, Luangdilok N (1975) A long-term foundation failure caused by dragdown on piles. Proceedings of the Fourth Southeast Asian Conference on Soil Engineering, Kuala Lumpur, pp 4.15–4.24 2. Terzaghi K, Peck RB (1948) Mechanics in engineering practice. Wiley, New York 3. Indraratna B, Balasubramaniam AS, Phamvan P, Wong YK (1992) Development of negative skin friction on driven piles in soft Bangkok clay. Can Geotech J 29:393–404 4. Poorooshasb HB, Alamgir M, Miura N (1996) Negative skin friction on rigid and deformable piles. Comput Geotech 18(2):109–126 5. Hanna A, Sharif A (2006) Negative skin friction on single piles in clay subjected to direct and indirect loading. Int J Geomech (ASCE) 6. Lu WT, Leng W, Wang Y-H (2005) In-situ tests on negative friction resistance of abutment piles in soft soil. Chin J Geotech Eng 27(6):642–645 7. Azizul Hoque M (2006) Coupled consolidation model for negative skin friction on piles in clay layers. A thesis in the Department of Building, Civil an Environmental Engineering, Concordia University, Montreal, Quebec, Canada

Underground Construction in Cold Regions

Ventilation Shafts Freezing Protection Under the Influence of Negative Temperatures Evgenii Kozin, Dmitrii Burin, Alexander Lediaev, Alexander Konkov, Yuri Filonov and Anatolii Novikov

Abstract In the winter operation process of the subway ventilation shaft freezing of the lining may occur, which during the long-term operation leads to its increased wear or even destruction with the soil release into the shaft. This article is devoted to the development of the foam glass concrete thermal insulation jackets design and methods of their construction, which allow carrying out ventilation shaft lining insulation along with its strengthening. In the course of the research, design solutions were developed, the necessary material properties were determined, and mathematical and physical modeling of the structure was performed. The studies were carried out for the conditions of St. Petersburg, but the experience gained in the framework can be used in ventilation shafts freezing protection operated in more severe conditions. Keywords Ventilation shaft · Foam glass concrete · Thermal insulation

1 Introduction One of the most acute problems associated with the ventilation shafts operational reliability in negative temperatures is freezing of the lining. The winter air temperature can drop to −25 °C and below, which leads (in the mode fresh air ventilation) to freezing of both the lining and the soil along its contour. When soil and water freeze in the space behind the lining, it is experiencing significant additional loads. This leads to significant ventilation shaft structural wear, deformations, and damage of liner plates, up to their destruction and release of water and ground masses, i.e., to emergency situations.

E. Kozin · D. Burin St. Petersburg Metro SUE, 28 Moskovskiy Prospekt, St. Petersburg 190013, Russian Federation A. Lediaev (B) · A. Konkov · Y. Filonov · A. Novikov Emperor Alexander I St. Petersburg State Transport University, 09 Moskovskiy Prospekt, St. Petersburg 190031, Russian Federation e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_53

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This article is devoted to the development of the foam glass concrete thermal insulation jackets design and methods of their construction, which allow carrying out ventilation shaft lining insulation along with its strengthening. The studies were carried out for the conditions of St. Petersburg, but the experience gained in the framework can be used in ventilation shafts freezing protection operated in more severe conditions.

1.1 Description of Ventilation Shafts Technical Condition in St. Petersburg The winter air temperature can drop to −25 °C and below, which leads (in the mode of fresh air ventilation) to freezing of both the lining and the soil along its contour. The majority of ventilation shafts in St. Petersburg are laid in the weak watered soils of quaternary deposits. When soil and water freeze in the space behind the lining, the lining experiences significant additional loads. This leads to significant wear of the ventilation shaft design, increase in the rate of corrosion processes, deformations, and damage to the liner plates, up to their destruction and release of water and ground masses into the shaft, i.e., to emergency situations (Fig. 1).

Fig. 1 Destruction of liner plates because of the water freezing behind the lining

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1.2 Goals and Objectives of the Research The aim of the research was to develop the foam glass concrete thermal insulation jackets design and methods of their construction, which allows preventing ventilation shaft lining freezing along with its strengthening. The following studies were performed: – the comparative analysis of different reinforcement and lining thermal insulation variants was made; – the required foam glass concrete parameters for making thermal insulation jackets were obtained using mathematical modeling method; – foam glass concrete composition selection with the set characteristics and their test for thermal conductivity, strength and water resistance was made; – the thermal insulation shirt physical full-scale model simulation and the technology of its device was carried out; – the basic technological requirements for materials and work production revealed during full-scale physical model construction were developed.

2 Variants of Ventilation Shaft Capital Repair Decisions To analyze the state of the problem and for further research the cast iron liner plate ventilation shaft design was adopted.

2.1 Reinforced Concrete Insulation Jacket with the Polymer Waterproofing Membranes In recent years, reinforced concrete jackets are used for ventilation shafts repair to enhance the damaged lining. At the same time, the issue of thermal insulation remains unresolved. The implementation of reinforced concrete insulation jacket precedes the lining corrosion cleaning, replacement of bolted connections, and filling liner plate cells with mortar or fine concrete. At the next stage, the internal waterproofing is arranged. Waterproofing is made of PVC membranes. Subsequently, a reinforced concrete insulation jacket is installed. The advantage of this method is the use of standard technologies for insulation jacket made of monolithic reinforced concrete with hydro-insulation and high structural strength. Among the disadvantages are as follows: a significant number of technological operations, long construction time, high cost of waterproofing works, and the complete lack of thermo insulation.

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Fig. 2 Reinforced concrete jacket with non-removable thermal insulation formwork design

2.2 Reinforced Concrete Jacket with Extra Insulation There are various options for shaft thermal insulation associated with the installation of thermal insulation panels of different materials. The option with fixed formwork and thermal insulation material shown in Fig. 2 deserves the greatest attention [1]. Lining preparation technology, waterproofing, and concreting are the same as reinforced concrete jacket option, and the only difference is the non-removable formwork made of heat-insulating material. The thermal insulation properties of such structure are questionable since it is difficult to achieve reliable thermal insulation at a formwork thickness of 50–75 mm, and the materials with the lowest heat conductivity coefficient does not match the necessary structural strength sufficient for the loads perception during concreting. If the same non-removable heat-insulating formwork of a considerable thickness (150–250 mm or more) is used, invalid shaft cross-section reduction can occur.

2.3 Reinforced Concrete Jacket with Special Concrete Types with High Thermal Insulation Properties This option is the most expedient as the strengthening and heat insulation functions are combined into a single structure on the basis of special types of concrete [2–4]. It

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is assumed that in this case, the insulation jacket concreting occurs with the simultaneous filling of the liner plates, and thus, a sufficiently time-consuming operation is excluded. In the course of the research, the analysis of concrete types with significant thermal insulation properties which would simultaneously have sufficient structural strength was carried out. As a result of the analysis, it was established that the most rational option is the use of foam glass concrete [5–12]. Foam glass is unique eco-friendly insulation with almost unlimited service period. Foam glass retains its physical properties throughout the structure exploitation period. The main foam glass granules properties are the following: – excellent thermal insulation properties; – complete environmental safety; – incombustibility, vapor impermeability, and water resistance. Thus, the use of foam glass granules in the form of a filler to create a special concrete with thermal insulation properties is the optimal solution. As a result of the comparison above, the design of a reinforced concrete jacket made of foam glass concrete was adopted.

3 Foam Glass Concrete Insulation Jacket Design Calculation and Experimental Research 3.1 Mathematical Models Research To determine the necessary foam glass concrete jacket thermal insulation parameters, a calculation model shown on Fig. 3 was developed. Cast iron lining ventilation shaft with outer diameter 5490 mm, the lining inner diameter of 5100 mm, and the liner plate cross section of 195 mm was considered. The soil mass temperature at the 60–70 m average shaft depth increases in depth from about +5 to +12 °C. The calculation model average soil mass temperature is +8 °C. The maximum air temperature inside the shaft was taken as −25 °C. To simplify the calculations, it was assumed that this temperature is presenting in the shaft constantly. According to the calculation and theoretical studies results, it was found that at thickness of 300 mm, foam glass concrete thermal conductivity coefficient should be less than 0.2 W/(m K).

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Fig. 3 Shaft insulation calculation model

3.2 The Composition Selection for Foam Glass Concrete Insulation Jacket Based on the objectives, to form a thermal insulation jacket inside the underground railway ventilation shafts, it is required to use a material with the following technical characteristics: • • • •

not less than 7.5 MPa compressive strength not less than F100 frost resistance not more than 0.2 W/(m K) thermal conductivity not less than W6 water resistance.

The selected parameters are determined on the basis of existing national standards and are sufficient to ensure the load-bearing capacity and thermal insulation efficiency. In order to solve this problem, the mineral origin lightweight composite material (foam glass concrete) development was performed. The optimal composition selected during the tests was used for concreting the shaft model.

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Fig. 4 Full-scale model scheme

3.3 Full-Scale Physical Model Experimental Study The study of chosen insulating composition ability was performed on a special physical model in 1:1 scale. The model represents a section of ventilation shaft made of cast iron liner plates with 5.5 m outside diameter with foam glass concrete reinforced jacket operating at variable temperatures. The full-scale model scheme is shown in Fig. 4. The model was established in the following sequence: 1. 2. 3. 4. 5.

Construction of cast iron liner plates simulating the insulation shaft section. Liner plates inner surface waterproofing construction. Reinforcement installation. Temperature sensors and recording equipment installation. Insulation jacket concreting (Figs. 5 and 6).

For research conduction, a special climate system which allows maintaining temperature inside of the freezing chamber in the range of −25 to −30 °C was arranged. A general view of the climate system is presented in Fig. 7. During the experiment, the model temperature was recorded at different levels of temperature effects at different depth points—on the inner surface of the insulation jacket, at the level of the first and the second row of reinforcement metal, at the level of liner plates ribs and back, and behind the lining in the soil massive. The measurements were carried out for three weeks.

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Fig. 5 Temperature sensors installation and preparation for concreting

Initially, in the inside of the freezing chamber an average temperature was about −23 °C for one week. During this time, the temperature in the level of the first row of reinforcement metal fell to −14 °C, in the level of the second row—to −2 °C, and in other levels, the temperature decreased slightly (from +6 to +8 °C to +4 to +6 °C). In the second stage, the temperature rise was modeled. Inside the freezing chamber, the average temperature was maintained at about −7 °C for one week. During this time, the temperature at the level of the first row of reinforcement metal increased to −3 °C, at the level of the second row—up to +3 °C, and in other levels, the temperature returned to the initial values (+6 to + 8 °C). In the third stage of the simulation, the maximum possible average cooling temperature (for this freezer) of −27 °C for 11 days was maintained in the freezing chamber. During this time, the temperature in the level of the first row of the reinforcement metal dropped to −17 °C, in the level of the second row—to −6 °C, and in other levels, the temperature reached values +2 to + 4 °C. It should be noted that at the time of exposure to cold air with a temperature below −25 °C for 11 days (which exceeds the maximum recorded period of such temperatures according to weather observations in St. Petersburg—7 days), there was no lowering of the temperature in the level of the ribs and the back of the lining, as well as in the model of the soil massive below the temperature of 0 °C. Thus, it is possible to acknowledge that the design of a heat-insulating jacket meets the

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Fig. 6 Model after formwork removal

requirements and is suitable for protection of ventilating shafts from freezing. The results are presented in Fig. 8.

4 Results of the Research 1. To ensure the ventilation shafts, operational reliability in the conditions of negative temperatures composition of the insulating material with characteristics that provide for shield from freezing with simultaneous increase of the structure bearing capacity was selected. The material has passed a set of necessary tests for strength, frost resistance, and water resistance in accordance with applicable regulations. 2. When the temperature inside the chamber was below −10° (including up to − 25 to −30°) lasting 24 days, complete insulation jacket freezing did not happen; 3. At the contact of the lining, outer contour and watered soil temperature have not dropped to the freezing temperature of water; 4. According to the results of the experiment, the temperature at the contact of the cast iron lining and the soil was higher than the results of mathematical modeling. This is because in the mathematical model that was used, worst case scenario

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Fig. 7 Test bench general view

Fig. 8 Measurement results

was the impact of −25 °C infinite negative temperature. The realistically possible period of maximum negative temperatures was not considered. 5. The concept of ventilation shaft insulation in the form of foam glass concrete insulation jacket proved its viability and effectiveness. 6. The developed thermal insulation design can be recommended for operated ventilation shafts.

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Acknowledgements We thank Konkov S. A. from Baltic State Technical University «VOENMEH» named after D. F. Ustinov for the technical translation.

References 1. Lediaev AP, Kavkazskii BN, Chumov MB, Sokornov AA, Patent № 2655712 Russia, IPC E21D 1/16, E21D 5/08, E21D 11/10, E21D 11/38. Method of reconstruction of the shaft with lining plates, (RU) – 2017126002 2. Liu WV, Apel DB, Bindiganavile VS (2011) Thermal characterization of a lightweight mortar containing expanded perlite for underground insulation. Int J Min Miner Eng 3(1):55–71 3. Liu WV, Apel DB, Bindiganavile VS (2014) Thermal properties of lightweight dry-mix shotcrete containing expanded perlite aggregate. Cement Concr Compos 53:44–51 4. Elrahman MA, Chung S-Y, Stephan D (2019) Effect of different expanded aggregates on the properties of lightweight concrete. Mag Concr Res 71(2):95–107 5. Ivanova SM, Chulkova IL (2005) Composite foam glass concrete. Build Mater 2005(10):22–28 6. Saulin DV, Rozhkova AV (2017) Research of alkali-silicate interaction of foam glass fillers with cement binder. Bull Perm Nat Res Polytech Univ Chem Technol Biotechnol 1:89–105 7. Komkova AV, Rachynskaya MP (2012) Foamglass and its application in Russia. Mod Sci Res Innov 5(13):18–20 8. Minko N, Beam OV, Evtushenko EI, Arzew VM, Sergeev SV (2013) Foam glass is a modern and effective inorganic insulating material. Fundam Res 6–4:849–854 9. Osipov AN (2013) Energy-efficient, fireproof thermal insulation material - foam glass. Roof Insul Mater 2:17–18 10. Dementev EG, Skvortsov DA (2015) Foam glass as an energy-and resource-saving thermal insulation material. In: Regional economy: current issues and new trends. Collection of scientific papers, 2015, Ulyanovsk State Technical University, Ulyanovsk, pp 230–232 11. Ivanova MS, Ivanenko AV (2017) Foam glass - a promising material of our time. Univ Sci 2(4):58–60 12. Barysheva OB, Giniyatullin AA (2017) Foam glass - modern effective inorganic thermal insulation material. In: The quality of the urban environment: construction, architecture and design. Materials of the all-Russian scientific and practical conference, 2017, Irkutsk National Research Technical University, Irkutsk, pp 35–40

Justification of Engineering Solution on Rebuilding Severomuysky Railway Tunnel Ventilation Simon G. Gendler

and Mikhail R. Belov

Abstract The purpose of this study was to develop proposals on upgrading heating and ventilation systems of the Severomuysky Railway tunnel with respect to rolling stock’s traffic increase. Field studies of operating heating and ventilation systems were performed in winter to this end. Field studies included measurements of the velocity and air temperatures distribution lengthwise of the tunnel during absence period train and in the period of train moving. The main factors determining heating and ventilation regimes were defined and technical solutions were proposed for further development of the existing systems. On the basis of theoretical and empirical data, the upgrade solutions of the heating and ventilation systems were justified in the event of double increase of rolling stock traffic. Keywords Railway tunnel · Ventilation · Heat regime · Unit-heater · Amount of traffic · Piston effect · Air consumption · Automatic gate · Equivalent equilibrium volumetric activity of radon

1 Introduction Severomuysky railway tunnel (SMT), built-in 2003, is the longest tunnel in Russia [1]. In order to ensure safe operation of the tunnel, a ventilation system is used that provides an adequate air supply during an annual period and distributes the air over the traffic tunnel, service tunnel, shafts, shaft sidings and crossings and functions alongside with an outdoor air system in winter until positive temperature establishes [1, 2]. The requirements towards the heating and ventilation systems determined the possibility of icing and fogging prevention [3] as well as the decrease of volumetric activity of radon in air of mining workings [4].

S. G. Gendler (B) · M. R. Belov Saint-Petersburg Mining University, 21-ya liniya VO, 2, 199106 Saint-Petersburg, Russia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_54

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Trains pump large amounts of cold outdoor air into the tunnel due to a piston effect [5–9], such that the air travels considerable distances in the direction of train movement from each tunnel portal. Additionally, tunnel’s air is cooled as a result of heat exchange with train surfaces temperature of which equals outdoor air temperature. Since it was impossible to eliminate or mitigate the piston effect of a moving train and in order to maintain positive temperature in the tunnel, an approach compensating for the cold pumped by trains was used when there were no trains travelling [1, 2]. Air is supplied into SMT’s mine workings by main ventilation fans, which are installed in a crossing that connects the ventilation shaft and traffic tunnel, alongside fans used for distributing air between the traffic and service tunnels [1]. An important element of the ventilation system is portal gates that are used to control air flows [2]. Geometry of the SMT mine workings is available in [1]. During the winter season the outdoor air entered the tunnel by means of the natural draught [10–13] or/and fans as well as the piston effect from the trains through the tunnel portals and it was removed through the ventilation shaft. During the initial period of operation of the SMT, outdoor air heating was performed by unit-heaters located in ventilation buildings next to the tunnel portals and by additional unit-heaters installed in dedicated chambers 250–300 m away from the west and east portals. In spite of the fact that without trains the temperature of the air being heated by unit-heaters reached 35–45 °C, this air moving towards the ventilating shaft brought cold air into the tunnel caused by trains at distances from the portals exceeding 3000 m. Regular cross direction movement of the trains created in the middle of the tunnel an area of lower temperatures compared to those after unit-heaters. With the outdoor air temperature being −30 to −35 °C, the temperature in the area dropped below 0 °C, what resulted in icing. For this reason, it was necessary to redistribute unit-heaters along the tunnel by means of deploying additional heat-up systems 3520 m away from the east portal and 4370 m from the west portal. Winter 2017 field studies included efficiency evaluation of the existing heating and ventilation equipment, finding its weaknesses as well as main opportunities for upgrading of heating and ventilation systems in the event of a double increase in rolling stock traffic.

2 SMT’s Heating and Ventilation System Study 2.1 The Purpose and Task of the Study The purpose of the study was to determine actual aerodynamic and heat parameters of the heating and ventilation systems.

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The tasks to be solved: • To define actual air consumption distribution per an SMT mine workings; • To study the piston effect created by a freight train depending on different position of the portal gates; • To evaluate unit-heater efficiency installed next to portals; • Measuring air temperature distribution along the tunnel with units installed for local air heating; • To measure volumetric activity of radon in the traffic and service tunnel.

2.2 The Results of Measuring Air Consumption and Air Movement Directions During SMT’s Operation Air consumption and its movement directions in SMT mine workings were determined by means of air flow measurement along mine workings according to methodology [14]. To measure air speed and its thermodynamic parameters MES-200 thermal anemometer [15] was used. Air flow directions through mine workings according to the measurements are shown in Fig. 1. 9

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Fig. 1 Ventilation scheme for Severomujsky tunnel in winter: 1—traffic tunnel (TT); 2—service tunnel (ST); 3—ventilation shaft (VSh); 4—crossing (Cr); 5—bypass tunnel (BT); 6—ventilation room with main fans (VR); 7—ventilation crosscut (VCrc); 8—ventilation building (VB); 9— additional unit-heaters (AH); 10—fans for air-splitting (Fsp); 11—fans for recirculation air (Frec); 12—unit-heaters for recirculation air (UHrec); 13—local unit-heaters (LH); 14—air staple shaft (Assh); 15—automatic gates (AG)

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According to the measurements, outdoor air enters the traffic tunnel (TT) through the West and East portals, then it gets heated up by unit-heaters located in ventilation buildings (VB) and by additional unit-heaters (AH). As soon as the air reaches ventilation crosscuts (7), one part of it is sent to the service tunnel where it was split into two flows. One of the flows moved towards a bypass tunnel (BT) where it mixed with air from the traffic tunnel (TT). Another air flow moved through the service tunnel towards ventilation buildings (VB) at the West and East portals, then it was heated up by unit-heaters (12) and sent into the traffic tunnel (TT) by fans (11). Another part of the air after the ventilation crosscuts (VCrc) moved through the traffic tunnel (TT) to the crossing (Cr) and forth where was bleed off through an air staple shaft into the service tunnel (ST). After mixing, the whole air volume from the traffic tunnel (TT) and service tunnel (ST) was sent through the bypass tunnel (BT) into the ventilation shaft (VSh) to reach the surface. During the field study, main fans (VR) were off and their inputs were shut with dump doors. Airflow at the portals without trains was 35–50 m3 /s, service tunnel areas between the ventilation crosscuts and ventilation buildings was 6–19 m3 /s, the airflow that reached surface leaving the shaft amounted to 50–70 m3 /s. The difference between the airflow was caused by the piston effect that could not be avoided during the field study while the railway tunnel was in operation. Moreover, during observations, it was noted that not only the absolute air consumption values, but also the direction of movement changed inside both the traffic (TT) and service tunnels (ST).

2.3 Studying the Piston Effect Created by Moving Rolling Stock in the Tunnel In order to evaluate the piston effect of rolling stock air speed (consumption) was measured that entered the tunnel through portal sections. The measurements were performed at the East portal alongside a freight train moving westwards (the direction of a natural draught was from West to East). In order to eliminate the influence of portal’s resistance on the velocity field, the measurement point was located at a distance 10 times exceeding the hydraulic diameter of the tunnel. Air speeds were recorded every 30 s in the measurement point during the process. The measurements were taken before the train entered the tunnel and immediately it reached the test point. The train consisted of 85 cars. Average train’s speed in the tunnel was approximately 51 kph. The results of the measurement are shown in Fig. 2. The analysis of the measurements showed that the train by entering the portal caused the natural air flow eastwards direction to change (negative air consumption value on the diagram). A significant drop in air consumption was caused by shutting the East portal gates after the train passed by (point 1). As the train moves westwards,

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air consumption continuously goes down. After the West portal gates were open, the air flow at the measurement point grew by 20 m3 /s (point 2). The area of the graph between point 2 and 3 shows the behaviour of the amount of air entering the tunnel with a moving train, with open West portal gates. As the train leaves the tunnel, air consumption drops (point 4). As the train completely leaves the tunnel with open West portal gates, air consumption grows approx. by 25 m3 /s (point 5) due to a lower aerodynamic resistance of the tunnel. After the West portal gates are shut, air consumption drops to zero and air begins its eastward movement again. Average air consumption calculated during the existence of the piston effect was 82.2 m3 /s, and the piston effect lasted for 27 min. Comparing the piston effect in winter and in summer [2] with the above-mentioned settings of portal gates opening/closing shows that average air consumption nearly doubles with the gates open. Calculations performed according to paper [5] regarding the field study conditions revealed that the estimated value of the average air consumption is 74 m3 /s what deviates from the empirical data only by 10%.

2.4 Studying Temperature Conditions at the Portal Areas Air temperatures before and after the unit-heaters installed in the ventilation building (VB) at the East portal were measured without trains and with trains leaving or entering the East portal. Alongside measuring the temperature, air volumes entering the unit-heaters were measured. Data analysis makes it is possible to conclude that the direction of train’s movement regarding the portal with unit-heaters exerts ultimate influence on the resulting air temperature. When a train enters the portal bringing outdoor air to the unit-heaters, return air temperature from the unit-heaters does not exceed 7–13 °C. When a train leaves the portal, unit-heaters are supplied with tunnel

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air with average temperature amounting to the average temperature of an adjacent tunnel section. As a result, unit-heaters’ output temperature reaches 30–43 °C and the heated air is removed from the tunnel. The amount of air supplied to the unit-heaters does not change depending on the train’s direction and it is 13–15 m3 /s. Thus, a unit-heater located at the exit portal virtually heats-up only the portal area and the outdoor air outside the portal, what decreases its energy efficiency. Besides the efficiency of the portal unit-heaters average temperatures at the portal areas were measured while there was a train inside the tunnel. The cross-section where the temperature was measured at coincides with the airflow measuring points. According to the data analysis shown in Fig. 3, air temperature in the tunnel before a train entered it was 17 °C. After the train passes the measurement point, usually there is a significant drop of 13 °C. The temperature remains nearly constant for 18 min after the train leaves. It goes back to its initial values in 35–40 min later.

2.5 Temperature Measurement Results of the Air Distributed Along the Tunnel The changes in air temperature along the tunnel were measured for the same heating system but after additional unit-heaters were installed at 3520 and 4370 m away from the East and West portals correspondingly Fig. 4). Data analysis showed that using the distributed heating system allowed increasing the temperature in the middle section of the tunnel up to positive values where it used to go below 0 °C.

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Fig. 4 Air temperature distribution along the tunnel

2.6 Evaluating Volumetric Activity of Radon in the Traffic and Service Tunnels The evaluation of radiation environment was performed by equivalent equilibrium volumetric activity of radon (EEVARn) in the traffic and service tunnels. The traffic tunnel shows normal values of EEVARn [4], but the service tunnel showed a 2–2.5 times excess of EEVARn, especially in the air entering the bypass tunnel (BT). The reason for this is regular changes in air movement direction due to the piston effect and air recirculation among the portals and ventilation crosscuts that lead to the accumulation of radon in the air. The comparison of average volumetric activity of radon in tunnel’s mine workings and the volumes of water drained from the tunnel showed a linear correlation between those two values with a coefficient no less than 0.7. This means it is possible to stabilize radiation environment not only through ventilation improvements but also decreasing the amount of drain water containing radon in the tunnel.

3 Approaches to Rebuilding Heat and Ventilation Systems Upgrading in the Event of Rolling Stock’s Traffic Increase Field studies of existing heat and ventilation systems in the SMT helped to find out the details of their operation with current rolling stock traffic and to suggest technical solutions how to upgrade the systems in the event of a double increase in the traffic.

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In order to define heat and ventilation systems’ parameters in the event of rolling stock’s traffic increase, a simulation model was created to study the aerodynamics of the tunnel’s ventilation depending on different traffic intensity and speeds in the traffic tunnel (TT) [16, 17]. The considered cases included one or two trains travelling with the speed of 60 and 80 kph. Simulation results showed that the average amount of air entering the tunnel when the piston effect was online and the train speed was 60 kph was 70 m3 /s in case of one train travelling and changed to 96 m3 /s in case of two freight trains. If the speed was 80 kph, the amount of air entering the tunnel increased from 110 m3 /s to 120 m3 /s correspondingly. Those data were used to calculate air heating system capacity [18, 19]. It turned out that in case of a double increase in rolling stock’s traffic the capacity of the heat system needs to be increase two and threefold depending on train schedule and speeds. On the basis of the field studies and simulations, a number of technical solutions were proposed for operating the SMT with the increased rolling stock’s traffic meeting the requirements from Sect. 2. The solutions include: • deploying additional heat systems along the tunnel and simultaneous increase of unit-heaters’ capacity at the portals; • controlling the performance of unit-heaters at the exit portals to decrease energy consumption; • ventilation the service tunnel with heated outdoor air by a separate ventilation system instead of ventilating the tunnel by means of air recirculation.

4 Conclusion The following information was found on the basis of field studies and simulations: • the main factors affecting the operation of current heat and ventilation systems of the outdoor air are travelling freight trains up 1200 m long at a speed up to 60 kph and the temperature difference between the tunnel portals of 10–15 °C, extremes being from −25 to −35 °C; • regular changes in air movement directions due to the piston effect and air recirculation among the portals and ventilation crosscuts, what results in accumulating radon in the air, should be acknowledged as the reasons for the increase in equilibrium volumetric activity of radon in tunnel’s mine workings; • to meet the requirement of preventing icing in the event of a double increase in rolling stock’s traffic, it is necessary to enhance the capacity of the heat system by 2–3 times depending on train schedule and speeds; • the solutions proposed allow meeting the requirements that guarantee safety of the rolling stock in case of increasing its traffic.

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References 1. Gendler SG, Sokolov VA (2003) The choice of operation regimes for an air quality maintenance system in the Northern Mujsky Railway Tunnel. In: 11th international symposium aerodynamics and ventilation of vehicle tunnels. BHRg, Switzerland, pp 289–308 2. Gendler SG, Sokolov VA (2006) The results of ventilation tests during practical use of the Severomujsky railway tunnel. In: 12th international symposium aerodynamics and ventilation of vehicle tunnels. BHRg, Slovenia, pp 451–462 3. SR 120.13330.2012 (2012) Subway. Revised edition of SNiP32-02-2003. Official publication. M., Minregion, Russia 4. Standard of a Radiation Safety (SRS-99/2009) (2009) Ministry of Health of the Russian Federation. Saint-Petersburg 5. Gendler SG (2013) Peculiarities of control ventilation in the Kuznetsovsky railway tunnel. In: 15th international symposium on aerodynamics, ventilation and fire in tunnels. BHRg, Spain, pp 309–323 6. Tsodikov VYa (1975) Subway ventilation and heat supply systems. Nedra, Moscow 7. Yushkovsky EM (1981) Air circulation in the subway ventilation systems with different venting schemes. J Vent Coal Mines Ore Mines 8:104–111 8. Henson DA, Hoff MacD, Guwthorpe RG, Porc CW, Johnson T (1982) The aerodynamics and ventilation of a proposed channel tunnel. In: 4th international symposium aerodynamics and ventilation of vehicle tunnels. BHRg, UK, pp 1–14 9. Henson DA, Bradbury WMS, Hoff MacD, Atkius WS (1991) The aerodynamics of channel tunnel. In: 7th international symposium aerodynamics and ventilation of vehicle tunnels. BHRg, UK, pp 927–956 10. Vasserman AD (1982) Specific heat regimes in underground structures with heat transmission to the rock mass. J In Phys Process Min 11:49–56 Saint Petersburg, Russia 11. Roche L (1991) Meteorological influence on tunnel ventilation: tree new field experiments. In: 7th international symposium on the aerodynamics and ventilation of vehicle tunnels. BHRg, UK, pp 513–543 12. Weiss HH, Dolejsky K (1985) An investigation of the atmospheric pressure differences affecting the longitudinal ventilation of road tunnels. In: 5th international symposium on the aerodynamics and ventilation of vehicle tunnels. BHRg, France, pp 98–115 13. West A, Pope CW (1985) Wind induced flow and resistance measurements in a rock hewn tunnel. In: 5th international symposium on the aerodynamics and ventilation of vehicle tunnels. BHRg, France, pp 347–371 14. Kirin BF, Dikolenko EJ, Ushakov KZ (2000) Aerology underground construction. Nedra, Moskow 15. Dyadkin YuD (1968) Mining thermo physics foundations for mines collieries of the North. Nedra, Moskow 16. Rogov EI (1973) Theory and methods of mathematical simulation production process in mining practice. Nauka, Alma-Ata 17. Paleev DJ, Lukashov OJ, Kosterenko VN, Timchenko AN (2011) Computer technology for task emergency control plan. Publisher Mining. Industrial security, Moscow 18. Amano K, Mizuta Y, Hiramatsu Y (1962) An improved method of predicting underground climate. Int J Rock Mech Min Sci Geomech Abstr 19:31–38 19. Starfiedd AM, Bleloch AL (1983) A new method for the computation of heat and moisture transfer in partly wet airway. J S Afr Inst Min Metall 163–269 20. Bogaert G (1970) Maintaining the tunnels of French Railways (SNCE). TunnS TunnIng 5:21– 26

Particularity and Prediction Method of Ground Settlement Caused by Subway Tunnel Construction in Permafrost Area Guangming Yu , Ruixue Ge, Xiankun Zeng , Yingnian Yu, Zhuang Zhang, Xianguo Meng and Yongjun Qin

Abstract During the construction of subway tunnels in permafrost areas, there are more factors of permafrost deformation in the deformation of rock stratum and ground settlement above the tunnels. Due to the frost heave effect of soil freezing in winter and the thawing phenomenon of frozen soil during thawing and thawing in spring, the ground settlement will occur, so the law of ground settlement caused by subway tunnels and its impact on ground construction facilities are more complex. The characteristics of surface heave caused by frost heave in winter and thawing caused by thawing in spring are studied. The evaluation method of ground thawing caused by subway tunnel construction in permafrost area is given. The ground settlement during tunnel construction in seasonal permafrost area is studied through specific engineering examples. The research shows that the ground settlement caused by tunnel excavation in this case area accounts for 53% of the total ground settlement, the ground settlement caused by frost heave accounts for 27% of the total ground settlement, the ground settlement caused by thawing and thawing of tunnel frozen soil accounts for 20% of the total ground settlement. The research results can provide reference for the understanding of ground settlement caused by tunnel construction in permafrost areas and its disaster protection. Keywords Permafrost · Subway · Tunnel · Settlement · Particularity prediction method G. Yu (B) · Y. Qin College of Architecture and Civil Engineering, Xinjiang University, Urumqi 830047, China e-mail: [email protected] G. Yu · R. Ge · X. Zeng School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao University of Technology, Qingdao 266033, China Y. Yu Qingdao Company, Zhongqi Jiaojian Group Co., Ltd., Qingdao 266300, China Z. Zhang · X. Meng Urumqi Urban Rail Group Co., Ltd., Urumqi 830000, China © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_55

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1 Introduction With the rapid development of society, urban problems such as dense population, space congestion, and traffic jam are prominent. The development and utilization of urban underground space are the only way for the healthy development of cities. Many scholars in the world call the twenty-first century the century of underground space development and utilization [1]. At present, in the construction wave of revitalizing the development of Northeast and West China, cities such as Harbin and Urumqi have successively built subway. When constructing subway in these cold areas, the ground heave will occur when the soil layer freezes in winter, which will cause the ground heave. When the frozen soil thaws in spring, the ground subsidence will occur again, which will lead to the ground subsidence caused by tunnel construction. The problem is more complex. Many scholars have studied the ground settlement caused by tunnel construction in cold areas [2–9]. Taking the Santunbei Station to Xinjiang University Station of Urumqi Metro Line 1 as an example, this paper monitors the ground settlement during tunnel construction, analyzes the influence of temperature change on ground settlement, summarizing the settlement caused by tunnel excavation, ground frost heave, and thawing of frozen soil during tunnel construction in seasonal permafrost area of Urumqi. At the same time, the evaluation method of ground subsidence caused by subway tunnel construction is given.

2 Project Overview The total length of the interval from Santunbei Station to Xinjiang University Station is 738.412 m, which is located in the beach area. There is a thicker silt backfill lake layer in the interval, the lithology is worse than that of other rocks and soil layers, the rock quality is softer, joints and fissures are developed, and it is easy to weathering and peeling off. It has the characteristics of rapid expansion of water absorption, mud, softening and dehydration cracking, shrinkage deformation, and so on. It belongs to very soft rock. There are two layers of groundwater in the site, which are quaternary pore water and bedrock fissure water. Urumqi is located in a severe cold region. Generally speaking, Urumqi starts snowing every year from October, snowing from November to February of the following year, and beginning to melt snow in March. The temperature during the snowfall period will reach −30 °C. The maximum seasonal frozen soil depth is 162 cm, but the temperature from March to June can reach 25 °C, and the ground settlement is easily affected by the frost heave and thaw settlement of seasonal frozen soil. In the process of frozen soil thawing, with the increase of soil temperature, frozen soil gradually melts, the melting of ice invading body in soil appears consolidation, the volume of soil shrinks and the bearing capacity decreases, and then, the settlement and melting phenomenon occurs on the ground. Therefore, in the design stage of tunnel

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freezing engineering, in addition to predicting the ground frost heave displacement, a reasonable method should also be used to predict the amount of ground settlement and thawing that may be caused. These methods are helpful to take corresponding control measures of surface subsidence and subsidence in the actual construction process.

3 Ground Settlement Monitoring 3.1 Monitoring Content In order to better understand the law of temperature change in the process of tunnel excavation, the Infrared thermometer of Raytek DT-8861 shown in Fig. 1 is used to monitor the environmental temperature, and the ground settlement is monitored on the spot at the same time.

3.2 Layout of Monitoring Points Settlement monitoring points should be arranged at locations that can reflect settlement characteristics and facilitate monitoring. Generally, strip-type and cross-type observation networks are used to arrange observation points. Steel nails and concrete piles are used to arrange observation points. Settlement monitoring points are laid within 3–4 times of the predicted diameter of the tunnel outside the rupture surface. A total of 9 monitoring points are laid out in one cross section. The distance between the two monitoring points is 2–5 m, and the monitoring points near the middle line of the tunnel are arranged more densely. As shown in Fig. 2, the ground subsidence is monitored by the rear intersection method. The direction and distance of two known points are observed from any station. The coordinates of the instrument center on the station are calculated by coordinate transformation, and then, the new coordinates of the remaining points are monitored.

4 Analysis of Ground Settlement The time chart of temperature at the site is shown in Fig. 3. Because the settlement law of each monitoring point on the ground is basically the same, only the monitoring point 5 near the tunnel and the monitoring point 1 far away from the tunnel are taken for monitoring, and the time chart of the ground settlement of the two monitoring points is shown in Fig. 4.

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4.1 Ground Settlement Caused by Tunnel Excavation As can be seen from Fig. 4, the ground settlement of the tunnel began from August 15, 2016 to October 31, 2016. The ground settlement increases gradually with the excavation of the tunnel. The ground settlement and deformation caused by the excavation of the tunnel are mainly caused by the contraction of the excavation surface caused by the movement of surrounding rock and soil to the excavation space. The maximum settlement of the tunnel is about 7 mm.

4.2 Tunnel Settlement Caused by Ground Frost Heave From Figs. 3 to 4, it can be seen that the ground settlement of the tunnel began to rise as a whole from November 2, 2016, and the maximum uplift is about 3.5 mm, which is caused by frost heave of the tunnel stratum. Tunnel uplift caused by frost heave of tunnel stratum offsets the settlement caused by tunnel excavation, which is beneficial for controlling the final settlement of tunnel.

4.3 Settlement Caused by Thawing and Thawing of Tunnel Frozen Soil As can be seen from Figs. 3 to 4, the ground settlement value of the tunnel began to increase from February 15, 2017, and the process lasted until April 2, 2017. This process is due to the tunnel ground settlement caused by thawing and thawing of frozen soil. It can be seen from Fig. 4 that within two months after thawing of frozen soil, the settlement of tunnel is obvious, the maximum settlement is about 2.8 mm, then the settlement tends to be gentle, and the final settlement of tunnel is about 7–8 mm. Due to thawing and thawing of frozen soil, the frozen wall is in a rapid thawing stage. The temperature of the frozen wall increases rapidly, and the strength decreases dramatically. In addition, there is a gap between the frozen wall and the initial support, which leads to obvious ground settlement in the first two months. Although the freezing wall continued to melt in the later stage, the melting speed was slow, and the grouting was continuously carried out, so the settlement of the tunnel was slow and tended to be stable in the later stage. In addition, through the points 1 and 5 in Fig. 4, it can be seen that the ground settlement value at point 5 is slightly larger than that at point 1 in the whole tunnel construction process, which indicates that the closer to the center line of the tunnel, the greater the settlement value. Based on the above analysis, it can be seen that the ground settlement mainly occurs during tunnel excavation in seasonal frozen soil, accounting for 53% of the total settlement; the ground settlement caused by ground frost heave accounts for

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27% of the total ground settlement, and the ground settlement caused by thawing and thawing of tunnel frozen soil accounts for 20% of the total ground settlement.

5 Prediction Method of Thawing Value of Ground Settlement Caused by Subway Tunnel Construction In the process of thawing, the frozen soil will shrink, and the thawing of frozen soil will cause the compaction settlement of the soil, which will lead to the ground settlement. The volume of frozen soil decreases after thawing, its thawing shrinkage can be expressed by the amount of thawing shrinkage per unit length of frozen soil, that is, the coefficient of thawing settlement ε1 is ε1 =

h × 100% h

(1)

In the formula (1), ε1 is the coefficient of thawing settlement (%), h is the thickness of thawing layer (m), and h is the stabilized thawing shrinkage of frozen soil (m). In permafrost areas, unless the soil is very special, the frost heave rate usually does not exceed 5%, the frost heave rate of general soil is 2–5%, and the silt can reach 3–4%. Due to thawing, the thawing settlement coefficient varies with the soil quality. For some soils, such as silt, the structure of frozen soils is vulnerable to damage, and the thawing settlement coefficient may exceed the frost heave rate. In the process of thawing of frozen soil, the thawing settlement can be regarded as a random event. Therefore, the ground settlement and deformation caused by thawing of frozen soil can also be calculated by stochastic medium theory. Considering tunnel excavation under the protection of the freezing ring is shown in Fig. 2. The cross section of tunnel excavation is circular, and the initial radius is A. After the tunnel is completed, the radius shrinks uniformly. When the ground freezing is completed, the outer radius of the freezing ring is R, the outer radius of the freezing ring becomes R1, and the inner radius becomes R1 after the completion of the tunnel because the uniform deformation after the tunnel is excavated. At this time, the outer radius of the freezing ring becomes R1, and the inner radius of the freezing ring becomes R1. R1 = R − A

(2)

when the thickness of freezing ring is R1 − A, the thawing settlement coefficient of frozen soil is ε1 , and the radial thawing shrinkage of frozen soil after thawing R is R = ε1 (R1 − A)

(3)

After thawing, the frozen soil in the whole frozen ring shrinks due to thawing and reflects to the ground to form ground settlement. Regardless of the thawing process

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Fig. 5 Surface settlement and deformation of thawing settlement of frozen soil

of the frozen soil, the ground settlement W (X ) caused by the thawing of the frozen soil should be equivalent to the settlement caused by the uniform contraction of the region R with the outer radius R1, which can be obtained as follows (Fig. 5). r 2 θ2 w2 (X, r , θ )dr dθ

W (X ) =

(4)

r 1 θ1

Similarly, for the tunnels with other cross-sections in frozen area, such as the horseshoe shape, only need to determine the integral area according to the specific tunnel cross-section form, use the similar method of circular area to calculate the ground subsidence caused by thawing settlement of frozen soil. The above formulas for calculating ground settlement contain double integrals whose integral functions are not integrable. These integrals can be calculated by quadrature method of Legendre Gauss. According to the programming method of tunnel excavation ground settlement, a calculation program can be compiled to calculate the ground settlement caused by thawing settlement of circular tunnel in permafrost area.

6 Conclusion In view of the characteristics and prediction methods of surface heave caused by frost heave in winter and thaw caused by thawing in spring in Urumqi, some studies have been carried out. The conclusions can be summarized as: 1. In the construction of tunnels in seasonal frozen soil, the ground settlement mainly occurs in the settlement caused by tunnel excavation, accounting for about 53% of the total settlement; the ground settlement caused by ground frost heave accounts

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for about 27% of the total ground settlement, and the ground settlement caused by thawing and thawing of tunnel frozen soil accounts for about 20% of the total ground settlement. 2. The closer the ground is to the center line of the tunnel, the larger the settlement value is, on the contrary, the smaller the settlement value is, which is mainly due to the construction of the close tunnel. 3. Ground settlement caused by thawing of frozen soil can be predicted by stochastic medium Theory. Acknowledgements The present work is supported by the National Natural Science Foundation of China (51674150) and the Construction of Science and Technology Projects in Urumqi (2016002).

References 1. Xiankun Z (2018) Study and application of analysis method for surrounding rock stability of shallow neighbourhood metro tunnel. Xinjiang University 2. Chenxing W, Yuancai L, Dewen L (2018) The study of the soil freezing method in subway construction. For Eng 34(02):89–94 3. Yong S, Kai L, Yuyong L (2013) Monitoring system for the freeze-thaw circle around tunnels in a plateau featuring frozen ground. Mod TunnLing Technol 50(06):14–18 4. Quanbin S, Ping P, Yingming Z (2017) Adfreezing strength at the interface between frozen soil and structure: research status and prospect. J Glaciol Geocryol 39(06):1298–1306 5. Haibing C, Limin P, Tenglong Z (2014) A duration prediction model of surface thawing settlement in construction period of tunnel with horizontal freezing method. Rock Soil Mech 35(02):504–510 6. Dejing T, Mingnian W, Dagang L (2006) Prediction of surface movement and deformation caused by the freezing method construction of tunnels. Mod TunnLing Technol 06:45–50 7. Xifa Z, Ji C, Dong Z (2002) Application of thawing settlement coefficient to the research on the roadbed frost damage of freeway in seasonal frost region. J Glaciol Geocryol 24(5):634–638 8. Haitao C (2004) A research over environmental impact parameter of manual horizontal ground freezing in a metro tunnel. Railw Stand Des 1:61–63 9. Xinmin S (2003) Characteristics of tunnel design in permafrost area. J Railw Eng Soc z1:106– 107

Artificial Freezing Method in Geotechnical and Tunneling Applications Martin Ziegler

Abstract The artificial freezing of soils for sealing and solidifying the subsoil has a long tradition. Originally developed for shaft construction in water-bearing soil and rock, where it is still used today, the artificial freezing method has recently also been increasingly used in tunnel construction. The main areas of application are the extension of mechanically driven segment tubes to underground stations and the subsequent construction of cross passages between the separate tunnel tubes. Both brine freezing and the liquid nitrogen method are used. The freezing method can be used in almost all soils, is easy to control and due to the latent heat, it has sufficient reserves in the event of temporary failure of the freezing equipment. In addition, the frozen area can practically be restored to its original state after the freezing measure has been completed. The procedure finds limits because of the strong heat input at higher groundwater velocities. In addition, the unavoidable heave in cohesive soils due to the volume expansion of the water and the formation of ice lenses often pose a problem, which, however, can be countered to a limited extent by appropriate operation of the freezing plant. The paper shows different applications and limits of the freezing process in geotechnical practice and tunneling. Keywords Artificial soil freezing · Thermo-hydro-mechanical behaviour of frozen soil · Practical applications

1 Introduction 1.1 History and Development of the Method The freezing of soil for sealing and stabilising water-bearing layers has a long tradition dating back to shaft construction. It was first applied in 1862 at a mine shaft

M. Ziegler (B) RWTH Aachen University, Geotechnical Engineering, Aachen, Germany e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Petriaev and A. Konon (eds.), Transportation Soil Engineering in Cold Regions, Volume 1, Lecture Notes in Civil Engineering 49, https://doi.org/10.1007/978-981-15-0450-1_56

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in Wales [1] and patented one year later by Friedrich Hermann Poetsch [2]. In addition to the application in shaft construction still carried out today, the process was also increasingly used in tunnel construction in the 70s and 80s of the last century. However, due to the high expenditure and the immense costs, the application was mostly limited to those cases in which no other technical solution was possible. This situation has changed significantly in the last 1–2 decades. First of all, compact and mobile freezing units have been developed, with which a freezing measure can be carried out much more cost-effectively. On the other hand, the area of application for the freezing process was significantly extended. The newer safety regulations for traffic tunnels, for example, require cross passages every 300–500 m, which can be safely driven with the freezing method in tunnels in groundwater or even under open water. Furthermore, due to the increased use of tunnel boring machines in underground railway construction, the entire lines are often first driven in one go and the extension in the stations is only carried out at a later point in time, often with the help of the icing method (Fig. 1). Overall, the freezing procedure is a very safe method because it can be easily controlled. It can also be used in almost all soils and is nearly completely reversible. Negative side-effects are the heave phenomena observed in fine-grained soils and the viscous behaviour of frozen soil, which leads to creep deformation. The method is limited by insufficient water saturation, but above all by high groundwater flow velocities.

Fig. 1 Extension of shield driven tunnels in subway station by soil freezing (Brochure of Berlin Transport Company (BVG), U55 Berlin)

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1.2 The Principle of the Method In principle, a distinction is made between brine freezing and icing with liquid nitrogen: In both cases, a refrigerant is fed into the ground via a downpipe under the protection of a freezing tube and then flows upwards again in the annular space between the freezing tube and the downpipe. Heat is extracted from the soil, gradually freezing the pore water and creating a frozen soil. Freezing with brine. The system consists of three closed circuits, whereby the refrigeration circuit is decisive for freezing the soil (Fig. 2). A calcium chloride brine (CaCl2 ) with a flow temperature of between −25 °C and −40 °C is usually used in it. Brine icing is used for longer icing measures with large icing cubatures. The construction site equipment is considerably more complex than nitrogen freezing. Nitrogen freezing. In nitrogen freezing, liquid nitrogen is fed directly at a temperature of −196 °C into the downpipe, where the liquid nitrogen evaporates and flows back in gaseous form in the annulus and is released directly into the environment. The liquid nitrogen is either taken directly from a tanker truck or temporarily stored in a silo. The construction site equipment is much smaller and less complex than for brine freezing, but the operating costs are considerably higher due to the consumption of liquid nitrogen. Nitrogen freezing is therefore mainly used for smaller measures or where a closed frozen body has to be achieved within a short time. Kühlwasserkreislauf cooling water circuit Kondensator condenser

Kältemittelkreislauf refrigerant circuit

Drossel expansion valve Verdampfer evaporator

Kühlturm cooling tower

Kühlwasserpumpe cooling water pipe Kompressor compressor

Fig. 2 Cooling system with brine [3]

Kälteträgerkreislauf cooling agent circuit

Solepumpe brine pump

Gefrierrohr freeze pipe Fallrohr downpipe

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2 Behaviour of Frozen Soil 2.1 Thermal Principles of Heat Transport in Soil In the unfrozen saturated state, soil is a two-phase mixture of solid matter and water. In the frozen state, the ice is added as the third phase (Fig. 3). As a result of a temperature gradient, an energy transfer takes place in the form of a heat transport. This always takes place from the area of the higher to the lower temperature. In the soil, it is essentially described by the transport mechanisms conduction (heat conduction) and convection (heat flow). Heat radiation as a third mechanism is only of secondary importance in the soil. In convection, the heat transport takes place through a movement of the fluid particles. For freezing measures in the technical field, the forced convection in a groundwater flow, which is caused by potential differences in the fluid, is of particular importance. In general, the heat transport in an isotropic and porous medium in the presence of a laminar groundwater flow can be described by the well-known differential equation: cv,G

   ∂T = {∇}T · (λG · {∇}T ) − cv,w · {∇}T · T · v f + q˙t . ∂t

(1)

The term on the left-hand side of the equation describes the change in the heat or energy content of the soil volume. The terms on the right describe the heat flow due to conduction and forced convection by groundwater flow. The value q˙t [W/m3 ] represents a source term with which local heat sinks as well as sources within the soil volume can be considered. The quantities cv,G and cv,w [J/(m3 K)] describe the volumetric heat capacity of the solid or water. The quantity λ [W/(mK)] represents the thermal conductivity of the solid, vF corresponds to the flow velocity of the water. The thermal characteristic values cv and λ are temperature-dependent, which must be considered in a realistic calculation of a freezing measure. Also, the latent heat at the phase transition has to be considered, which is released during the change from

nw 1 1-nw multiphase system (soil)

water solid

nw n ni

1-n

unfr. water ice solid

unfrozen soil frozen soil (two-phase model) (three-phase model)

Fig. 3 Multiphase model of totally saturated soil in unfrozen and frozen state according to [4]

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liquid to solid by rearrangement of the water molecules into the crystalline structure of the ice, which delays the freezing process. Conversely, when changing from ice to liquid, a large amount of heat of fusion must be introduced into the system, which provides additional safety if, for example, the freezing plant fails for a limited period of time. The viscosity of the water also depends on the temperature, which in turn has a direct effect on the permeability of the soil and thus on the flow velocity and convective processes during heat propagation in the soil. If the soil freezes, only a part of the water passes into the frozen state at temperatures as low as −70 °C. The reason for the supercooled water is adsorption forces between the mineral grains and the surrounding water coats. Fine-grained soils with a high specific surface area, therefore, have a considerably higher unfrozen water content at the same temperature than coarse-grained soils [5]. The unfrozen water content plays an important role in the freezing process and the heat propagation in the soil. Simplified it can be calculated with the following equation, where T [°C] is the absolute temperature and a and b are soil-dependent parameters to be determined in the experiment. wu (T ) = a × |T |b

(2)

2.2 Temperature-Dependent Behaviour of Frozen Soil The strength and deformation properties of frozen soil are strongly dependent on time and temperature in addition to the soil type (Fig. 4). The uniaxial strength of 10

sand

A

5

B

D

C

E F 0

G 5 10 vertical strain ε1 [%]

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vertical stress σ 1 [MN/m²]

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E

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20 0

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0,002 0,006

0,02

0,06

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particle diameter [mm]

Fig. 4 Stress strain lines for different frozen soils from uniaxial compression tests at a deformation rate of 1%/min and −10 °C according to [7]

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frozen soil samples increases with decreasing temperature and increasing deformation speed, but decreases again with increasing salt content at the same temperature. Further details can be found in the relevant literature [6]. In phase 1, the creep rate decreases very rapidly after initially high values, only to remain approximately constant in phase 2 over a more or less long period of time. In phase 3, the crystal structure is softened, accelerating the creep deformations again and finally breaking. Orth [8] has found in his investigations that a pronounced phase 2 with a constant creep rate, as propagated by [5], for example, is usually not present. Rather, in phase 2 a turning point of the creep curve has to be observed at which the creep speed has a minimum. This point can be defined as the service life of an icing measure since the deformations also inevitably lead to fracture (Fig. 5). By evaluating numerous own tests and those from the literature, Orth [8] was also able to establish that the product of creep rate and time at the inflection point is constant for different applied stresses, different temperatures, and different soils. ε˙ m · tm = constant

(3)

From this, the curve of the normalized creep rate shown in Fig. 6 can be plotted over the normalized time, which can be expressed by the following equation:   −β  t t ε˙ · = exp(−β) · exp β · ε˙ m tm tm

(4)

The parameter β can be determined according to [8] from the following equation: β=

ln(˙ε0 /˙εm ) ln(tm /t0 ) + t0 /tm − 1

(5)

Fig. 5 Creep test with determination of allowable life time t m of frozen body according to [7] and [3]

strain [-] strain rate [1/min]

For the reference time t0 with the associated strain rate, Orth [8] proposes one minute and defines the deformation that has occurred so far as elastic strain. The further course must then be obtained from Eq. (4) by numerical integration. Usually, the strain obtained up to a point at time t1 is then used in simplified form to determine

phase 1

phase 2

phase 3

tm

time t [min]

m 0

10

547

εm tm

2

constant

m

Fig. 6 Approximated creep rates from tests according to [8]

[-]

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1

10

0

-3

10

10

-2

-1

10

10

0

t/t m [-]

a modulus of elasticity valid for this point in time. This allows the one-dimensional creep behaviour of frozen soils to be described with sufficient accuracy. Cudmani [9] extended the above-mentioned relationships to the general three-dimensional case. Due to the temperature dependence of the thermal and mechanical soil properties and their effect on the hydraulic soil properties, calculations of frozen soil are a coupled thermo-hydro-mechanical problem, which can usually only be solved numerically.

3 Specific Problems in Practical Application 3.1 Frost Heave In addition to the problem of accurately describing the time- and temperaturedependent behaviour of frozen soil, there are two major problems in the practical implementation of freezing measures. The first is due to the frost heave of fine-grained soils, the second to the influence of groundwater flow. Elevations result on the one hand from the nine percent volume increase of water during freezing and on the other hand from the formation of ice lenses, which are formed by the freezing suction at the icing front. There is extensive literature on ice lens formation, e.g. [10]. Regarding the special conditions of frost heave during freezing measures, please refer to Niggemann’s contribution to this conference [11]. In practice, attempts are made to minimise frost heave by intermittent freezing.

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Fig. 7 Freezing bodies in stagnant and flowing groundwater after 15 days [12]

3.2 Influence of Flowing Groundwater Due to the large heat capacity of water, flowing groundwater represents an enormous energy input, which can lead to the fact that the installed cooling capacity is not sufficient to close the frost body between the freezing lances at all. In practice, flow velocities above 2 m/day are problematic. Figure 7 shows the freeze body after 15 days freezing time for standing groundwater and a flow of 1.5 m/day. The picture on the right also shows the challenge for the numerical calculation. By closing individual gaps between the freezing pipes, the boundary conditions for the groundwater flow (“moving boundaries”) change permanently. It can be clearly seen that the frost body grows only long-steadily, especially in the inflow area. The problem can be further exacerbated if the growth of the frost body, e.g. in the direction of an aquiclude, causes a nozzle effect in the subsurface which increases the existing groundwater flow for continuity reasons. A simple solution in practice is not to arrange the freezing tubes equidistantly, but to compress them in the upstream area. If this is not sufficient, additional freezing tubes can be arranged in the freezing circuit or also outside in the upstream area for precooling. If the groundwater flow comes constantly from only one direction, the freezing pipes can also be moved out of the middle section of the freezing pipe circuit in the direction of the inflow. With the aid of such measures, the freezing time can be approximately halved.

4 Summary The freezing process, which has been successfully used in shaft construction for more than 100 years, has recently become increasingly widespread in civil engineering and especially in tunnel construction. The method is safe, easy to control and the interventions in the subsurface are almost completely reversible. The development of powerful compact freezing plants has also significantly improved the cost-effectiveness of the process so that in many cases it can compete with alternatives such as jet grouting. The lifting phenomena in freezing fine-grained soils as

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well as groundwater flows, if these amount to 2 m/day or more, are still problematic and require further research. Acknowledgements Most of the pictures and explanations were taken from an internal research report written by Dipl.-Ing. Thorsten Müller [3] to whom I want to express my sincere thanks.

References 1. Sanger FJ, Sayles FH (1979) Thermal and rheological computations for artificially frozen ground construction. Engineering Geology 13(1–4):311–337 2. Poetsch FH (1883) Verfahren zur Abteufung von Schächten in schwimmendem Gebirge. Patentschrift Nr. 25015 vom 27 3. Müller, Th (2019) Thermo-mechanische Kopplung beim Gefrierverfahren. Final research and development report, unpublished 4. Baier C (2008) Thermisch-hydraulische Simulationen zur Optimierung von Vereisungsmaßnahmen im Tunnelbau unter Einfluss einer Grundwasserströmung. Dissertation at the Chair of Geotechnical Engineering, RWTH Aachen, http://www.geotechnik.rwth-aachen.de/ mitarbeiter/Dissertationen/08-12_Baier.pdf 5. Andersland OB, Ladanyi B (2004) Frozen ground engineering, 2nd edn. John Wiley & Sons, Inc., NJ 6. Harris JS Ground Freezing in Practice. Thomas Telford, London 7. Jessberger HL, Jagow-Klaff R (2001) Bodenvereisung. Grundbau-Taschenbuch: Teil 2. Geotechnische Verfahren, vol. 6, U. Smoltczyk (Ed.), Ernst & Sohn, Berlin, 121–166 (1995) 8. Orth W (2018) Bodenvereisung. Grundbau-Taschenbuch: Teil2. Geotechnische Verfahren, vol. 8, K.J. Witt (Ed.), Ernst & Sohn, Berlin, 299–373 9. Cudmani R (2018) A Constitutive Model for Frozen Granular Soils. In: Proceedings of ChinaEurope Conference on Geotechnical Engineering, vol 2. Springer International Publishing. Cham 10. Konrad J-M (1994) Sixteenth Canadian geotechnical colloquium: frost heave in soils: concepts and engineering. Can Geotech J 31(2):223–245 11. Niggemann K (2019) Investigation of frost heave considering the boundary conditions of artificial ground freezing. In: Proceedings of the Conference Transportation Soil Engineering in Cold Regions 2019, Springer Series Lecture Notes in Civil Engineering 12. Ziegler M, Baier Ch (2007) Optimierung von Vereisungsmaßnahmen im Tunnelbau durch Anwendung numerischer Simulationen, Tunnel verbinden - Connections by Tunnels: Vorträge der STUVA-Tagung 2007 in Köln/ Hrsg.: Studiengesellschaft für unterirdische Verkehrsanlagen STUVA. Gütersloh: Bauverlag. 177–183