Technology Standard of Pipe Jacking [1st ed. 2024] 9819955963, 9789819955961

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Lu Wang · Zhiguo Wu · Yong Chen · Zhaoquan Wang · Chunwen Yan · Taotao Tong

Technology Standard of Pipe Jacking

Technology Standard of Pipe Jacking

Lu Wang · Zhiguo Wu · Yong Chen · Zhaoquan Wang · Chunwen Yan · Taotao Tong

Technology Standard of Pipe Jacking

Lu Wang School of Engineering and Technology China University of Geosciences (Beijing) Beijing, China

Zhiguo Wu Beijing Municipal Second Construction Engineering Co., Ltd. Beijing, China

Yong Chen Fujian Xinyongtong Trenchless Engineering Technology Co., Ltd. Xiamen, Fujian, China

Zhaoquan Wang Shaoxing Panshi Pipeline Engineering Co., Ltd. Shaoxing, Zhejiang, China

Chunwen Yan China Geological Equipment Group Co., Ltd. Beijing, China

Taotao Tong Foreign Languages Department University of Science and Technology of China Hefei, China

ISBN 978-981-99-5596-1 ISBN 978-981-99-5597-8 (eBook) https://doi.org/10.1007/978-981-99-5597-8 Jointly published with China Architecture Publishing & Media Co., Ltd. The print edition is not for sale in China (Mainland). Customers from China (Mainland) please order the print book from: China Architecture Publishing & Media Co., Ltd. Translation from the Chinese Simplified language edition: “顶管技术规程” by Lu Wang et al., © China Architecture Publishing & Media Co., Ltd. 2016. Published by China Architecture Publishing & Media Co., Ltd. All Rights Reserved. © China Architecture Publishing & Media Co., Ltd. 2024 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of 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 publishers, 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 publishers 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 publishers remain 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 Paper in this product is recyclable.

Preface

The Chinese version of this regulation was compiled by pipe jacking expert group of China Society of Trenchless Technology on the basis of “Technical Specification Construction of Pipe Jacking (trial)” which was an industry standard. The authors referred to the regulation and standard for gas, water supply and drainage, oil, industry, electricity and other underground pipelines and combined their practical working experience. Since the Chinese version was published, it has been well received by the industry. Foreigners are eager for an English version whose work related to no dig technology. Therefore, the translators have translated this regulation. This translated version will promote the exchange and application of pipe jacking technology all over the world. The regulation is divided into 17 chapters and one appendix. In this regulation, the specific steps of the pipe jacking have been described in detail. The specific operation of the pipe jacking has been standardized. The content covers a wide range, from the preparation work before the pipe jacking construction to the acceptance work after the pipe jacking construction, from the design of the pipe jacking pit, to the measurement work during the pipe jacking construction, from the introduction of the pipe jacking equipment to the specific steps of the pipe jacking: – Redefine the relevant terms; – Include main technologies related to pipe jacking engineering, engineering geological exploration, underground pipeline detection, pipe material, pipe jacking construction and monitoring, etc.; – The content should cover the construction method of pipe jacking as far as possible, mainly classified as open and closed pipe jacking; – A comprehensive discussion of commonly used pipe jacking construction methods and techniques, including design, construction and acceptance. The investigation, design, construction and quality acceptance of the pipe jacking project shall not only comply with the regulations, but also comply with the mandatory provisions of the relevant standards issued by the state and relevant competent authorities.

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Preface

This technical specification can be used as a reference for designers, technical personnel, construction personnel and pipe jacking quality acceptance personnel. Due to the translator’s limited English level, maybe there are some problems in translations. Please forgive me. Beijing, China Beijing, China Xiamen, China Shaoxing, China Beijing, China Hefei, China

Lu Wang Zhiguo Wu Yong Chen Zhaoquan Wang Chunwen Yan Taotao Tong

Acknowledgments

The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this book: This work was supported by the Natural Science Foundation of China (U22A20184). This work was supported by the Natural Science Foundation of China (41902320). Thanks to Prof. Wenjian Zhu of Beijing Institute of Exploration Engineering for offering professional advice for this book. Thanks to Senior Engineer Zhaoquan Wang and Zhiguo Wu for supporting the translation work of this book. Thanks to Prof. Yuanbiao Hu of China University of Geoscience (Beijing) for revising and proofreading the English of this book. Thanks to my students Fan Zhang and Zhide Chen for helping me drawing some pictures of this book. In addition, the authors express their appreciation to China Society for Trenchless Technology for providing data and materials.

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Contents

1

Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1

2

Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

3

Basic Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Pipe Jacking Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Pipe Jacking Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Pipe Jacking Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Pipe Jacking Construction Process . . . . . . . . . . . . . . . . . . . . . . . . .

5 5 6 6 7

4

Construction Organization Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Basic Requirements of Construction Organization Design . . . . . 4.2 Construction Organization Design Basis . . . . . . . . . . . . . . . . . . . . 4.3 Influencing Factors of Pipe Jacking Construction Design . . . . . . 4.3.1 Determination of Pipeline Location . . . . . . . . . . . . . . . 4.3.2 Determination of Pipe Jacking Method . . . . . . . . . . . . 4.3.3 Determination of Pipe Jacking Machine . . . . . . . . . . . . 4.4 Preparation of Construction Organization Design . . . . . . . . . . . . 4.4.1 Preparation Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4.4.2 Preparation Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9 9 9 10 10 11 15 17 17 18

5

Pipe for Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Basic Requirements for Pipe Materials . . . . . . . . . . . . . . . . . . . . . 5.3 Steel Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Reinforced Concrete Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Fiberglass Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.1 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.2 Mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.3 Pipe Production Requirements . . . . . . . . . . . . . . . . . . . .

23 23 24 25 27 41 41 43 43

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5.5.4 Appearance Quality Inspection . . . . . . . . . . . . . . . . . . . 5.5.5 Allowable Deviation of Dimension . . . . . . . . . . . . . . . . Prestressed Steel Cylinder Concrete Pipe . . . . . . . . . . . . . . . . . . .

44 44 48

6

Engineering Environment and Geological Survey . . . . . . . . . . . . . . . . 6.1 Engineering Environmental Survey . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Engineering Geological Survey . . . . . . . . . . . . . . . . . . . . . . . . . . .

61 61 62

7

Working Pit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Working Pit Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Acceptance of Working Pit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

69 69 69 72

8

Pipe Jacking Equipment and Instruments . . . . . . . . . . . . . . . . . . . . . . . 8.1 Unit Division of Pipe Jacking Equipment . . . . . . . . . . . . . . . . . . . 8.2 Pipe Jacking Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 Equipment Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

75 75 76 77

9

Jacking Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 Estimation of Jacking Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 Initial Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 Manual Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4 Drilling and Blasting Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 Water Flushing Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.6 Compaction Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.7 Mechanical Excavation Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . 9.8 Pilot Boring Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.9 Pipe Jacking with Earth Pressure Balance . . . . . . . . . . . . . . . . . . . 9.10 Slurry Balance Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.11 Air Pressure Balance Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . .

89 89 89 91 94 102 103 106 107 110 112 114

10 Special Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1 Micro-diameter Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 Extra-Long Distance Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . 10.3 Special Shaped Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4 Curve Pipe Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5 Vertical Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

117 117 117 118 119 120

11 Pipe Jacking Construction Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Corrective Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Measures to Reduce Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Measures for Entry and Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 Ground Deformation Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.5 Intermediate Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.6 Mucking Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.7 Anti-rotation Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.8 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.9 Pipe Lowering Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

123 123 127 130 131 132 134 135 136 138

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11.10 Power Supply Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 11.11 Ventilation Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 12 Treatment After Jacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1 Pipe Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2 Pipe Seams, Grouting Holes and Pipe end Closure . . . . . . . . . . . 12.3 Consolidation of Soil Outside Pipe . . . . . . . . . . . . . . . . . . . . . . . . . 12.4 Pipeline Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

141 141 141 142 142

13 Construction Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.1 Monitoring Time and Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2 Monitoring Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.3 Monitoring Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.4 Instrument Monitoring and Early Warning . . . . . . . . . . . . . . . . . . 13.5 Monitoring Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

143 143 143 144 145 146

14 Engineering Quality and Acceptance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.1 General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2 The Requirment of the Pipeline Appearance Quality . . . . . . . . . . 14.3 The Requirment of the Pipeline Allowable Deviation . . . . . . . . . 14.4 Requirements for Surrounding Environment Impact . . . . . . . . . .

153 153 154 154 154

15 Health, Safety and Environmental Protection Management . . . . . . . 15.1 Health Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1.1 Labor Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1.2 Healthcare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2 Security Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2.1 Basic Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2.2 Regulations on Safe Use of Electricity . . . . . . . . . . . . . 15.2.3 Safety Regulations for Electric Welding . . . . . . . . . . . . 15.2.4 Gas Welding Safety Regulations . . . . . . . . . . . . . . . . . . 15.2.5 Fire Protection Regulations . . . . . . . . . . . . . . . . . . . . . . 15.2.6 Windproof Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2.7 Lightning Protection Regulations . . . . . . . . . . . . . . . . . 15.2.8 Flood Control Regulations . . . . . . . . . . . . . . . . . . . . . . . 15.2.9 Winter Protection Regulations . . . . . . . . . . . . . . . . . . . . 15.2.10 Safety Regulations During Construction . . . . . . . . . . . 15.3 Management for Environment Protection . . . . . . . . . . . . . . . . . . .

157 157 157 157 158 158 159 159 160 161 161 162 163 163 164 164

16 Production Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.1 General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2 The Acceptance System for Equipment Installation . . . . . . . . . . 16.3 Post Responsibility System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4 Completion Inspection and Acceptance System . . . . . . . . . . . . . .

167 167 167 167 168

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17 Technical Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.1 Original Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.2 Reporting Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3 Filing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

169 169 169 169

Appendix: The Reference Table for Pipe Jacking Archives . . . . . . . . . . . . 171 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Chapter 1

Scope

This standard specifies the construction technology and related operations of pipe jacking. This standard is applicable to the construction of underground pipes or tunnels by pipe jacking, including pipes with circular, rectangular and other shapes in cross section.

© China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_1

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Chapter 2

Normative References

The following documents are indispensable for the application of this standard. For dated reference documents, only the dated version applies to this standard. For undated reference documents, the latest version (including all amendments) is applicable to this standard. “Standard for construction and acceptance of water supply pipe and sewerage pipe” GB 50268; “Technical specification for pipe jacking of water supply and sewerage engineering” CECS 246; “Jacking construction method for reinforced concrete sewer pipes” JC/T 640; “Concrete and reinforced concrete sewer pipes” GB 11836; “Compressive strength Test Method of concrete pipes” GB/T 11837; “Prestressed concrete cylinder pipe” GB/T 19685; “Specification of structural design of buried glass fiber reinforced plastic mortar pipeline of water supply and sewerage engineering” CECS 190; “Glass fiber reinforced plastics jacking pipe” GB/T 21492; “Glass fiber reinforced plastics mortar pipes” GB/T 21238; “Common Portland cement” GB175; “Sulphate resistance Portland cement” GB748; “Sulphoaluminate cement” GB 20472; “Sand for construction” GB/T 14684; “Pebbles and crushed stones for construction” GB/T 14685; “Cold rolled ribbed steel bars” GB 13788; “Steel for the reinforcement of concrete—Part 1: Hot rolled plain bars” GB 1499.1; “Steel for the reinforcement of concrete—Part 1: Hot rolled ribbed bars” GB 1499.2; “Cold-drawn low-carbon wire for concrete products” JC/T 540; “Hot-rolled plates, sheets and strips carbon structural steels and high strength low alloy structural steels” GB/T 3274; “Carbon structural steels” GB/T 700;

© China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_2

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2 Normative References

“Rubber seals—joint rings for water supply, drainage and sewerage pipelines Specification for materials” GB T 21873; “Hygienic standard for unsaturated polyester resin and glass fiber reinforced plastics used as food containers and packaging materials” GB 13115; “Liquid unsaturated polyester resin for fiber reinforced plastics” GB/T 8237; “Bisphenol-A epoxy resin” GB/T 13657; “Rubber gasket ring of prestressed and self-stressing concrete pipe” JC/T 748; “Safety regulations for blasting” GB 6722; “Code for construction and acceptance of earthwork and blasting engineering” GB 50201; “Technical standard for monitoring of building excavation engineering” GB 50497; “Code for safety of power supply and consumption for construction site” GB 50194; “Technical safety code for the management, operation, inspection and maintenance of hand-held motor-operated electric tools” GB/T 3787; “Emission standard environment noise for boundary of construction sites” GB 12523.

Chapter 3

Basic Rules

3.1 Pipe Jacking Diameter 3.1.1 Pipe jacking diameter series (nominal) includes (mm): 300, 400, 500, 600, 700, 800, 900, 1000, 1050, 1100, 1200, 1250, 1300, 1350, 1400, 1500, 1550, 1600, 1650, 1750, 1800, 1950, 2000, 2100, 2150, 2200, 2400, 2500, 2600, 2800, 3000, 3200, 3600,… 3.1.2 According to the diameter of the pipe installed, pipe jacking is divided into micro-diameter, small-diameter, medium-diameter, large-diameter, and megadiameter: 1.Micro-diameter pipe jacking (micro-tunnelling): a pipe jacking construction method that uses mechanical excavation to install pipes with an inner diameter of less than 800 mm (construction personnel cannot enter the pipe); 2.Small-diameter pipe jacking: a pipe jacking construction method that construction personnel can enter into the pipe to work, but cannot work completely upright in the pipe. Usually, the inner diameter of the pipes is greater than or equal to 800 mm and less than 1500 mm; 3.Medium-diameter pipe jacking: a pipe jacking construction method that construction personnel can enter into the pipe and work completely upright. Usually, the inner diameter of the pipeline is greater than or equal to 1500 mm and less than 2200 mm; 4.Large-diameter pipe jacking: a pipe jacking construction method for which a working platform is needed so that the construction personnel can work in the pipe. Usually, the inner diameter of the pipe is greater than or equal to 2200 mm and less than 3600 mm; 5.Large-diameter pipe jacking: a pipe jacking construction method where the inner diameter of the pipe exceeds the conventionally agreed pipe jacking diameter. Usually, the inner diameter of the pipe is greater than or equal to 3600 mm.

© China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_3

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3 Basic Rules

3.2 Pipe Jacking Length According to the distance of the pipe jacking, it can be divided into short distance, middle distance, long distance, and super long distance pipe jacking: 1.Short distance pipe jacking: a single-segment pipe jacking length is less than 100 m, usually intermediate jacking stations are not used; 2.Middle distance pipe jacking: a single-segment pipe jacking length is 100 ~ 400 m, usually intermediate jacking stations are required; 3.Long distance pipe jacking: a single-segment pipe jacking length is 400–1000 m, usually multiple intermediate jacking stations are required; 4.Super-long distance pipe jacking: a single-segment pipe jacking length is more than 1000 m; Usually intermediate jacking stations are used in group.

3.3 Pipe Jacking Method 3.3.1 According to whether the working plane is sealed or not, the pipe jacking construction methods are divided into two types: open type and closed type. 3.3.2 The open pipe jacking includes excavation type (manual type/machine-digging type/drilling and blasting type), extrusion type, grid type, water flushing type, etc. 3.3.3 The closed pipe jacking includes slurry balancing, earth pressure balancing, air pressure balancing and so on. 3.3.4 Open pipe jacking includes: 1.Manual pipe jacking: a manual pipe jacking construction method where rock and soil are excavated with hand-held tools; 2.Machine-digging pipe jacking: a pipe jacking construction method where rock and soil are excavated with various forms of excavators; 3.Drilling and blasting pipe jacking: a pipe jacking construction method where rock and soil are broken through drilling, charging, and blasting; 4.Grid pipe jacking: a pipe jacking construction method where the excavation surface of the pipe end is divided into several small excavation units, and each small unit is excavated separately; 5.Water flushing pipe jacking: a pipe jacking construction method where soil mass is impacted and broken with high-pressure water; 6.Extrusion pipe jacking: The front end of the pipe is designed with a bell mouth shape. When jacking, part of the soil enters the pipe and part of the soil is pushed to the outer circumference of the pipe; 7.Compaction pipe jacking: a pipe jacking construction method without excavation, and a pipe tip installed into the front end of the pipe pushes the soil to the outer periphery of the pipe;

3.4 Pipe Jacking Construction Process

7

8.Auger-boring pipe jacking: a pipe jacking construction method which uses the drilling machine to drill a hole and dumps soil mechanically. 3.3.5 Closed pipe jacking 1.Earth pressure balancing pipe jacking: a pipe jacking construction method where the stability of the excavation surface is maintained by adjusting the pressure of the muck in soil chamber; 2.Slurry balancing pipe jacking: a pipe jacking construction method where the stability of the excavation surface is maintained by adjusting the pressure of the slurry in slurry chamber; 3.Air pressure balancing pipe jacking: a pipe jacking construction method where air is filled into the excavation surface and the air pressure is used to maintain the stability of the excavation surface.

3.4 Pipe Jacking Construction Process The main process of pipe jacking construction is as follows: entering the site → measuring and positioning → confirming the starting jacking pit and arriving pit → installing pipe jacking equipment and auxiliary facilities → installation and acceptance → jacking and entering the hole → normal jacking → jacking and exiting the hole → removal of the jacking equipment → post-jacking processing → through acceptance → waste slurry treatment and site environmental restoration → dismantling.

Chapter 4

Construction Organization Design

4.1 Basic Requirements of Construction Organization Design 1. During the design and construction of pipe jacking, various factors should be considered comprehensively, and the method and technology of pipe jacking should be optimized to meet the requirements of pipeline installation and use, and to minimize the losses caused by improper design; 2. For major and technically complex pipe jacking projects, multiple schemes should be compared and feasibility analysis should be carried out; 3. Before construction design, carry out engineering geological survey and engineering environmental survey on the construction site, and fully grasp the detailed site information; 4. No construction organization design, or construction organization design without approval, shall not implement pipe jacking projects.

4.2 Construction Organization Design Basis 4.3.1 The design basis should consider the following factors: 1. 2. 3. 4. 5. 6. 7. 8.

Engineering design documents; Engineering geological survey report; On-site underground obstacle investigation report; Technical requirements for pipe jacking engineering; Relevant regulations, norms and standards; Inspection and evaluation report of facilities within the project’s impact range; On-site investigation; Contract or agreement.

© China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_4

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4 Construction Organization Design

4.3 Influencing Factors of Pipe Jacking Construction Design 4.3.1 Determination of Pipeline Location 1. Influence of soil quality on pipe jacking (1) Pipe jacking can be carried out in a variety of soils, including silty soil, clay, silt, sand, pebbles, gravel, and rocks; (2) For construction in different soil qualities, suitable pipe jacking construction methods and equipment should be selected. 2. The influence of pipe interval on pipe jacking (1) When the jacking pipeline and the existing pipeline are parallel to each other, the horizontal clear space should be determined according to factors such as soil quality, pipe type and diameter, buried depth of pipe, and should generally be greater than one times the outer diameter of the jacking pipe; (2) When the jacking pipeline intersects the existing pipeline, the vertical clear space should not be less than 0.5 times the pipe outer diameter and not less than 1.0 m for steel pipe, or not be less than one times the pipe outer diameter and not less than 2.0 m for reinforced concrete pipe; (3) When parallel pipelines are jacked at the same time, the minimum clear space between adjacent pipelines should be determined according to factors such as geological conditions, jacking method and construction sequence, and should usually be greater than the outer diameter of the larger pipeline; when the pipelines with different buried depths are jacked, it is advisable to jack in the pipeline with larger buried depth first; when jacking in different diameter pipelines, it is advisable to jack in the pipeline with larger section first; (4) When the clear space cannot meet the above requirements, corresponding measures such as soil reinforcement and pipeline isolation shall be taken. The space between the jacking pipeline and the existing underground pipeline shall also meet the requirements of the underground pipeline management unit. 3. The influence of the pipeline environment on pipe jacking (1) The jacking pipeline must avoid the influence range of underground obstacles; (2) When crossing a river, pipeline should be arranged below the scour line of the riverbed and meet the requirements of river planning; (3) When crossing roads and structures, it shall meet the protection needs of roads and structures;

4.3 Influencing Factors of Pipe Jacking Construction Design

11

(4) The influence of pipe jacking on surrounding buildings (structures) should be evaluated, and corresponding control standards and protective measures should be proposed, the management unit should be negotiated and communicated to meet relevant management regulations; if necessary, a safety assessment report for pipe jacking should be prepared; (5) When determining the location of the pipeline, the safety space between the pipe jacking pit and the surrounding buildings (structures) should also be considered. 4. The influence of covering depth (1) In unstable soil, the covering depth of pipe should be greater than 1.5 times the outer diameter of the pipe, and should be greater than 1.5 m; (2) When crossing a river, the covering depth should not be less than 1.5 times the outer diameter, and should not be less than 2.5 m; (3) When there is groundwater or when crossing a river, the covering depth should still meet the pipeline anti-floating requirements; (4) The covering depth of the air pressure balancing pipe jacking is relatively large, which should be greater than 2 times the outer diameter of the pipe, and should be greater than 4.0 m; (5) The covering depth of manual pipe jacking could be appropriately smaller, but it should not be less than 1.0 m; (6) When the covering depth cannot meet the above requirements, corresponding technical measures shall be taken.

4.3.2 Determination of Pipe Jacking Method 1. The determination principle of the pipe jacking method (1) Technical and economic comparisons should be made according to the geological conditions, hydrological conditions, pipeline design requirements and construction requirements; (2) It should be determined according to factors such as the distribution of harmful and toxic gases, underground obstacles, and the buildings that need to be protected; (3) When jacking in a single soil mass, it can be determined by referring to Tables 4.1 and 4.2; when jacking in a complex soil mass, comprehensive consideration should be given according to changes in soil quality; when jacking in pebbles, gravel, and rocks, the pipe jacking machines with crushing capacity or the open-type pipe jacking should be chosen; when ground deformation is required to be controlled or the space from underground structures (structures) is relatively smaller, closed pipe jacking should be selected. 2. Influencing factors of pipe jacking method selection

10–4

cm/s

★ ★

★ ★ ★

★

★★

★★

★★ ★★

★

Note: ★★—Suitable for use; ★—usable;

★

★

★

★★

★

★

★ ★

★★

with removable obstacles

★★ ★★

★ ★

★★

★

★★

★★

★★

★

★★

★★

★★

★★

★★

★

★★

★

★

★★

★

★

★ ★★

★

★★

★

★

★★

Pebbles, rocks

Gravel

Sand k < 10–4 ~ 10–3 cm/s

Sand k
2.0D and > 4m

> 1.5D and > 3m

> 2.0D and > 4m

> 1.5D and > 3m

> 1.5D and > 3m

> 1.5D and > 3m

> 1.0D and > 1m

overburden thickness H (m)

Table 4.2 Pipe jacking method selection reference table

Rock, hard soil

Soft and compactable formation

Clay, silt, sand

Clay, silt, sand, pebbles, gravel, above water level

Soft plastic, flow plastic clay, silt

Soft plastic and flow plastic clay

Use with caution in soft plastic and flow plastic clay

Applicable strata

Naturally stable

Extrusion

Naturally stable

Dewatering, grouting or aeration

Control the opening area, advancing speed and soil volume

Control the advancing speed and opening rate

Precipitation, grouting

Stratum stabilization measures

Small, normal construction deformation < 100mm

Medium, Elaborate construction deformation < 200mm

Large, Elaborate construction deformation < 300mm

Large, Elaborate construction deformation < 300 mm

Large, construction deformation < 300 mm

Medium, normal construction deformation < 200 mm

Larger, normal construction deformation < 300 mm

Ground deformation

(continued)

Permeability coefficient should be ≤ 10–4 cm/s

Remarks

4.3 Influencing Factors of Pipe Jacking Construction Design 13

300 ~ 1000

400 ~ 3600

400 ~ 3600

400 ~ 3600

Auger boring type

Earth pressure balance type

Slurry balance type

Air pressure balance type

Broken type

Thick Slurry type

8

9

10

11

12

13

1000 ~ 3600

1500 ~ 3600

Applicable diameter (mm)

Pipe jacking method

No

Table 4.2 (continued)

> 2.0D and > 4m

> 2.0D and > 4m

> 2.0D and > 4m

> 1.5D and > 3m

> 1.2D and > 2m

> 1.0m

overburden thickness H (m) Earth pressure balance

Stratum stabilization measures

Slurry balance

Air pressure balance

Gravels and pebbles Slurry balance with a particle size of less than 200mm

Gravel, pebbles, rocks

Clay, silt, sand, pebbles, gravel, soil containing boulders

Clay, silt, and sand Slurry balance with the content of pebbles and gravel < 20% and particle size < 50mm

Clay, silt, and sand Earth pressure with the content of balance pebbles and gravel < 20% and particle size < 100mm

Clay, silt, sand

Applicable strata

Medium, Elaborate construction deformation < 80mm

Medium, Elaborate construction deformation < 80mm

Small, Elaborate construction deformation < 50mm

Small, Elaborate construction deformation < 50mm

Small, Elaborate construction deformation < 30mm

Small, normal construction deformation < 30mm

Ground deformation

Remarks

14 4 Construction Organization Design

4.3 Influencing Factors of Pipe Jacking Construction Design

15

(1) Length factor: short-distance pipe jacking, manual pipe jacking is optional; medium and long-distance pipe jacking, machine-digging or balanced pipe jacking should be selected. (2) Pipe diameter factors: micro-diameter pipe jacking is not suitable for manual pipe jacking, and closed pipe jacking should be used; micro-diameter and small-diameter pipe jacking should be carried out by slurry balance; earth pressure balance is suitable for medium, large, and huge-diameter pipes; machine-digging pipe jacking is suitable for large and huge-diameter pipes; grid-type pipe jacking is mostly used in medium, large and huge-diameters. (3) Geological factors: when the stability of the soil is poor, it is not advisable to use an open pipe jacking; in case of pebbles, pipe jacking machine with second crushing function or thick slurry pipe jacking can be used; Drilling & blasting or pipe jacking machine with rock breaking function can be used for construction in the rock; the closed pipe jacking can be used in all kinds of soil; the extrusion pipe jacking should be applied when the soil is soft; Water flushing pipe jacking should be applied in clay, silt, and fine sand with relatively stable soil. (4) Groundwater factors: When groundwater is abundant, closed pipe jacking should be used; when there is no groundwater, open pipe jacking can be used. (5) Environmental factors: When the ground deformation requirements are strict or the distance to the underground structure is relatively small, the closed pipe jacking should be used; when the ground deformation amplitude is not required or the distance to the underground structure is larger, the open pipe jacking can be used. (6) Underground obstacles: when there are suspected underground obstacles that can be broken, open pipe jacking or air pressure balancing pipe jacking can be used; when there are suspected underground obstacles that can be broken, and the obstacle strength is small, a closed roof can be used. Pipe jacking method is not suitable for construction when there is suspected unremovable underground obstacle. (7) Construction period factors: When the construction period is relatively short, closed, extrusion, and extrusion pipe jacking should be used. (8) Economic factors: the direct construction cost of manual and extrusion pipe jacking is lower; the direct construction cost of closed pipe jacking is higher; the direct construction cost of broken pipe jacking is very high.

4.3.3 Determination of Pipe Jacking Machine 1. Selection of the cutter head of pipe jacking machine

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(1) The pressure of the soil chamber of spoke-type cutter head and convergent plate cutter head is closer to the actual earth pressure; (2) When the water content of soil reaches or exceeds the liquid limit, it is not appropriate to use spoke type and convergent plate type cutter head; (3) When the soil is very viscous, it is not suitable to use the panel-type cutter head; (4) With pebbles and gravel, it is not suitable to use the panel-type cutter head; (5) When the pebble content is high and the particle size is large, a crushing cutter head should be used; (6) When pipe jacking in rock, a crushing cutter head should be used. 2. Selection of muck transportation method (1) There are three muck transportation methods: truck transportation, slurry pipeline transportation, and soil pipeline transportation; (2) Truck transportation is often used for earth pressure balance pipe jacking and manual pipe jacking, slurry pipeline transportation is used for slurry pipe jacking; (3) Soil pipeline transportation is suitable for transporting cohesive soil with moderate moisture content; (4) Pipeline transportation should be used for medium and long-distance pipe jacking; (5) When using pipes to transport muck containing pebbles and gravel, measures must be taken to prevent the pipes from being blocked; (6) When slurry pipeline is used to transport muck with a large sand content, measures must be taken to prevent muck from settling in the pipeline; (7) For high viscous muck, after the muck is transported to the ground using the slurry pipeline, measures must be taken to separate the slurry as soon as possible; (8) When the site is narrow, there is no slurry treatment site or slurry is difficult to separate, it is not suitable to use slurry pipeline transportation. 3. Curve pipe jacking (1) When the curvature is small, a multi-section pipe jacking machine should be used; (2) An automatic positioning measuring equipment should be used for curve pipe jacking. 4. Gradient factor (1) For downhill pipe jacking, measures should be taken at the front end of pipe jacking machine to prevent the electrical equipment from flooding with water; (2) For uphill pipe jacking with large gradient, measures should be taken to prevent the pipeline from retreating; (3) When the gradient is large, measures should be taken to prevent the pipe jacking equipment from sliding on the guide rails or in the jacked pipeline.

4.4 Preparation of Construction Organization Design

17

5. Length factor (1) An automatic positioning measuring equipment should be used for long distance pipe jacking; (2) Intermediate jacking station must be used for long distance pipe jacking; (3) Pipeline transportation should be used for long-distance pipe jacking; (4) Intermediate pump should be added in the muck transportation pipeline for extra-long distance pipe jacking; (5) For extra-long distance pipe jacking, measures should be taken to solve the problem of voltage drop caused by long distance power supply of the pipe jacking machine; (6) Measures should be taken to solve the problem of oxygen supply and communication in the pipe for a long or extra long distance. 6. Pipe diameter factor (1) The jacking distance for small diameter pipes should not be too long, and the maximum jacking distance should not be greater than 200 D (D is the inner diameter of the pipe); (2) Construction personnel should not enter the pipeline with diameter less than 800 mm; (3) For pipelines with a diameter of less than 600 mm, construction personnel are strictly forbidden to enter; (4) For pipelines with a diameter of less than 600 mm, auger boring method should be used; (5) For pipelines with a diameter of less than 1200 mm, slurry balance method should be used.

4.4 Preparation of Construction Organization Design 4.4.1 Preparation Requirements 1. For major and technically complex pipe jacking projects, a feasibility analysis should be carried out before the design scheme is compiled. Based on full investigation and research, the feasibility analysis should be carried out according to the current standards and specifications, combining with the function of pipeline and the opinions of the owner, carrying out technical comparison of multiple schemes and technical verification of design and construction scheme. 2. Before determining the pipe jacking construction scheme, site engineering geological survey should be conducted to analyze the hydrogeology and engineering geology of the construction area; the site underground and surrounding structures should be investigated to fully grasp the site data related to the pipe jacking construction.

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4 Construction Organization Design

3. In the process of preparing the pipe jacking construction scheme and during pipe jacking construction, pipe jacking method, technology and parameters should be optimized according to the changes in the actual situation as the work gradually deepens and the level of understanding on hydrology, engineering geology and surrounding environment gradually improved. 4. The pipe jacking construction scheme must meet the requirements of the pipeline design document and the contract agreement. Based on the site survey, it should be prepared according to the existing production plan, material consumption, personnel and equipment allocation and cost quotas, etc., the equipment and best construction method and technology should be chosen according to the actual condition conditions to ensure the quality of the project and obtain the best economic benefits. 5. The original data of pipe jacking construction should be recorded, collected and sorted out. The original data must be true, accurate and reliable. 6. Pipe jacking construction personnel shall abide by this regulation and allow the construction unit to formulate corresponding implementation rules or supplementary regulations according to specific conditions during operation. 7. On site management work, corresponding management systems should be formulated referring to the relevant provisions in the project construction and municipal construction regulations and based on the actual situation. 8. When crossing important buildings, such as railways, highways, natural gas pipelines, etc., a safety construction evaluation report should be issued by professional evaluation company.

4.4.2 Preparation Content 1. 1 Construction standards and basis (1) The laws, regulations, rules, and norms on which the scheme is based should be indicated; (2) The design documents, geological survey reports, and underground obstacle survey reports on which the scheme is based should be indicated; (3) Other relevant information on which the scheme is based should be indicated. 2. Project overview (1) The project name, work content, project period and construction requirements should be stated; (2) The geographic location, traffic conditions, topography and climatic characteristics of the project should be explained; (3) The surrounding environment should be explained, including surrounding structures, underground pipelines, underground structures, and site construction conditions, etc.;

4.4 Preparation of Construction Organization Design

19

(4) The geological conditions should be explained, including engineering geological conditions and hydrogeological conditions, with emphasis on the main geological factors affecting jacking construction; (5) The plan, profile and geological profile of the pipeline should be drawn in accordance with the design location of the pipeline and the engineering geological survey report; (6) Project-related units should be introduced, including project construction units, design units, survey units, supervision units, general contractors, subcontractors, and other units related to the project. 3. Engineering Amount (1) The construction sequence should be explained according to the pipeline design situation and pipeline location; (2) The total amount of the project should be calculated in the order of construction. 4. Pipe jacking technical measures (1) Estimation of total jacking force and bearing capacity of jacking base; (2) The installation method of jacking base, sealing ring, foundation trench guide rail, pipe jacking machine, oil pump and oil cylinder should be attached with installation drawings; (3) Measures for pipe jacking entering and exiting of the hole; (4) Friction reduction measures for pipe jacking; (5) The discharge and disposal method of muck, and a map of the temporary storage location of muck should be attached; (6) Corrective measures for pipe jacking; (7) Pipeline positioning and measurement methods, measuring instruments used, and measurement accuracy analysis; (8) The control measures for ground deformation and surrounding environment influence; (9) Measures of setting up, installing, using, and dismantling of intermediate jacking station; (10) Ventilation, power supply and communication measures during pipe jacking construction; (11) Vertical transportation measures in pipe jacking construction; (12) Technical measures for key parts of the project; (13) Treatment measures after the pipeline is penetrated; (14) Special pipe jacking technical measures: such as long distances, curves, large gradient, gravel formations, rock formations, etc. 5. Monitoring measures (1) (2) (3) (4)

Monitoring objects, monitoring means and monitoring methods; Monitoring items, monitoring instruments, and monitoring frequency; Monitoring control values, including allowable values and alarm values; Monitoring technical requirements;

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(5) The composition of monitoring personnel. 6. Equipment selection The type of pipe jacking equipment should be determined according to pipe diameter, pipe jack length, estimated total jacking force, pipe jacking method, etc., including pipe jacking machine, intermediate jacking station, mud pump, main jacking pump station, main jacking cylinder, mud mixer, etc. The performance parameters of the main equipment should be indicated. 7. Site layout (1) The layout of the construction site should be determined based on the on-site investigation and jacking method; (2) At the jacking pit construction site, the specific locations of launch jacking pit, jacking equipment, pipes, temporary storage of muck, mud treatment equipment, vertical transportation equipment, etc. shall be determined; (3) At the construction site of the reception pit, the specific location of the reception pit and vertical transportation equipment should be determined. 8. Project quality requirements and guarantee measures (1) The project quality index should be put forward according to the specific situation of the project; (2) Quality assurance measures should include the following: pipeline jacking direction control, including measurement and positioning methods, correction methods; jacking control measures, including the preparation and use of friction reduction mud, and the use of intermediate jacking station; control measures for soil deformation and over-excavation; technical measures to ensure the quality of the project and solutions to technical difficulties. 9. Engineering safety measures (1) Feasible safety guarantee requirements and technical measures should be put forward; (2) Appropriate disaster prevention measures such as cold prevention, fire prevention, flood prevention and landslide prevention should be put forward; (3) Preventive and handling measures should be proposed for major accidents easily occurring; (4) According to the surrounding and underground existing buildings (structures), detailed protection measures should be proposed; (5) For possible major accidents, there should be a feasible emergency plan. 10. Project construction arrangement (1) A schedule of equipment, labor, materials, etc. required for construction and emergency should be provided;

4.4 Preparation of Construction Organization Design

21

(2) The time required to complete each project should be indicated; (3) The construction schedule plan should be compiled; (4) For seasonal construction, different construction management and technical measures should be proposed according to the characteristics of different seasons; (5) In the limited working space, specific measures for working in the limited space should be proposed according to the specific characteristics of the project. 11. Emergency plan (1) (2) (3) (4) (5)

Emergency plan for sudden events; Emergency plan for ground collapse; Engineering safety plan; Project quality plan; Environmental influence plan.

12. Construction organization and management measures (1) The health and environmental protection measures of construction personnel shall be proposed; (2) The construction organization and management system shall be determined; (3) Construction management measures should be formulated. 4.5 Requirements for preparation and approval of construction organization design 4.5.1 The construction organization design shall be prepared by technical staff under the auspices of the chief engineer of the construction unit. 4.5.2 After the construction unit has reviewed the construction organization design, it shall be submitted to the project issuing unit for approval. 4.5.3 The construction organization design shall be reviewed and demonstrated. 4.5.4 During construction, if the actual situation is found to be inconsistent with the construction organization design, it should communicate with the project issuing unit in time, and perform the design change procedures. The engineering design shall not be changed without consent.

Chapter 5

Pipe for Pipe Jacking

5.1 General Provisions 5.1.1 The pipe cross section of pipe jacking has round, rectangular and other shapes. 5.1.2 The types of pipes suitable for pipe jacking usually include steel pipes, reinforced concrete pipes, steel cylinder concrete pipes, glass fiber plastic pipes or other pipes. 5.1.3 The length of a single section of reinforced concrete pipe is preferably 2.0– 3.0 m, and the length of a single section of steel pipe is 4–10 m. The length for long-distance pipe jacking can be increased appropriately and determined according to the radius of the curve. 5.1.4 Pipe ovality: the difference between the maximum and minimum diameters perpendicular to each other on the same pipe cross-section shall be measured separately for the ovality of the socket and the ovality of the spigot. 5.1.5 Perpendicularity of pipe end face: take the plane perpendicular to the central axis of the pipe as the reference plane, measure the distance between the two sides of the pipe and the reference plane respectively, as shown in Fig. 5.1. If there is no plane for reference, assume that the pipe plane is turned by 180°, and then measure the angle between it and the horizontal line. The angle divided by 2 can indicate the verticality of the pipe end surface. The error of the perpendicularity of the pipe end surface shall meet the requirements of Table 5.1.

© China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_5

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Fig. 5.1 Measurement of the perpendicularity of pipe end surface

Table 5.1 Permissible error of perpendicularity of pipe end surface (mm)

Diameter

Concrete pipe Steel pipe Fiberglass pipe

300 ≤ D ≤ 600

2

1

1.5

600 < D < 1200

3

2

2.0

1200 ≤ D < 3000 4

3

2.5

3000 ≤ D

–

–

5

5.2 Basic Requirements for Pipe Materials 5.2.1 It should have excellent mechanical properties, including the ability to withstand certain static and dynamic loads, the ability to withstand internal and external pressures of the pipeline, and high axial load-bearing capacity. 5.2.2 Accurate dimensions should be ensured, including close fitting of the pipe joints, pipe end perpendicularity, pipe ovality, etc., and the pipes should be straight in the axial direction. 5.2.3 The pipe joint should have the ability to transmit axial loads. 5.2.4 When the pipeline joint has a certain angle of deviation, it should still have the water blocking capability.

5.3 Steel Pipe

25

5.2.5 The pipe and its joint should have the ability to resist chemical corrosion and mechanical damage inside and outside the pipeline, and the pipeline protection measures should be compatible with the pipeline jacking process and the ground conditions. 5.2.6 The pipe should have a quality certificate and documents that proves it has passed the retest according to the regulations.

5.3 Steel Pipe 5.3.1 The specifications and performance of the steel pipe should meet the engineering design requirements, and Q235B should generally be selected. 5.3.2 The thickness of pipe wall shall be the calculated thickness plus the thickness of the corrosion amount. The thickness of the corrosion amount shall be determined according to the service life and environmental conditions and shall not be less than 2 mm. The annual corrosion standard of steel pipe can be found in Table 5.2. 5.3.3 Weld line 1. One longitudinal weld line should be used in the same cross section of the coiled steel pipe. If two longitudinal weld lines are used, the spacing of longitudinal weld lines for large-diameter pipe should be greater than 300 mm, and the spacing of longitudinal weld lines for small-diameter pipe should be greater than 100 mm; 2. When coiled steel pipes are butt-connected, the pipe joint should be flat. When a 300 mm straightedge is used to check the joint longitudinally, the allowable deviation of dislocation in adjacent pipe walls is 0.2 times the wall thickness and not more than 2 mm; 3. When coiled steel pipes are butt-connected, the staggered distance of longitudinal weld positions in adjacent pipe sections should be greater than 300 mm. 5.3.4 The length of pipe section should not be less than 4 m, and the length of the pipe section for long-distance pipe jacking can be appropriately increased. 5.3.5 The allowable deviation of the geometrical dimensions of the steel pipe shall meet the requirements of Table 5.3.

Table 5.2 Annual corrosion standard of steel pipe (single side) Eroded environment Corrosion amount (mm/year)

Below groundwater level

Groundwater level change area

Seawater

Freshwater

Seawater

Freshwater

0.03

0.02

0.06

0.04

Above groundwater level 0.03

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5 Pipe for Pipe Jacking

Table 5.3 Allowable deviation of steel pipe dimension Item

Allowable deviation

Perimeter

D1 ≤ 600 mm

± 2.0 mm

D1 > 600 mm

± 0.0033D1

Ovality

0.005 D1 at pipe end, 0.01 D1 at other part

Perpendicularity of pipe end surface

0.001 D1 , and should not be greater than 1.5 mm

Radian

Measure the gap formed at the longitudinal seam of the inner or outer wall of the pipe with an arc-shaped plate, which should not be greater than 0.001 D1 and not greater than 4 mm; the gap between the longitudinal seam at a distance of 200 mm from pipe end should not be greater than 2 mm

Remark: D1 is the outer diameter of pipe (mm)

5.3.6 For butt welding, “V”-shaped bevels should be adopted for the weld lines of small-diameter pipes, and “K”-shaped bevels should be adopted for large-diameter pipes. Regardless of the bevels form used, the contact surface of the jacking iron should be flat. 5.3.7 For the quality inspection of steel pipe weld lines, non-pressure pipes shall not be lower than the level III standard of weld quality classification; pressure pipes shall not be lower than the level II standard of weld quality classification. 5.3.8 The anti-corrosion requirements are as follows: 1. The inside and outside of steel pipe should be treated with anti-corrosion treatment; 2. Within the width of 100 mm at both ends of pipe section, the quick-drying paint should be used for corrosion protection after the weld is qualified; 3. The anti-corrosion coating or cement mortar can be used for the anti-corrosion of the inner wall for water supply pipeline, and the anti-corrosion coating should have a sanitary inspection certificate. The thickness of the internal anti-corrosion layer with cement mortar can be selected within the range of 15–20 mm according to steel pipe diameter. The cement mortar should be mixed with non-toxic fiber materials to strengthen the crack resistance. The standard value of the compressive resistance of the cement mortar should not be less than 30 N/mm2 ; 4. Epoxy resin or epoxy asphalt can be used for the anti-corrosion of steel pipe outer wall. 5.3.9 The expansion change under the action of temperature difference shall be considered for steel pipe. When the pipeline length is more than 100 m, there should be a through-wall pipe in one foundation pit in which the steep pipe can expand and contract freely; when the length exceeds 600 m, there should be two through-wall pipes in both foundation pits where the steep pipe can expand and contract freely; when the length exceeds 1000 m, an expansion joint should be installed every 500 m.

5.4 Reinforced Concrete Pipe

27

If the steel pipe and the two foundation pit walls are rigidly connected, the bearing strength of foundation pit walls and the connection strength of pipeline under the action of the temperature difference must be checked.

5.4 Reinforced Concrete Pipe 5.4.1 The classification of reinforced concrete pipes is as follows: 1. According to the different requirements of external load-bearing strength, it is divided into three levels: I, II, and III, see Table 5.4; 2. Pipe connection methods include: flexible joint pipe, rigid joint pipe; 3. Rigid joint: In the working state, the adjacent pipe ends do not have the function of angular displacement and axial displacement, such as plug-in joint with fillers such as impermeable cement or expanded cement mortar, sleeve joint with cement mortar wipe tape or cast-in-place concrete, etc., in the form of flat face pipe, tongue-and-groove pipe, etc., as shown in Figs. 5.2 and 5.3; 4. Flexible joint: In the working state, the adjacent pipe ends allow a certain amount of relative angular displacement and axial displacement, such as the plug-in joint with elastic sealing ring or elastic packing, etc., with steel sockets, tongues and groove, double spigots, steel sockets and spigot and other forms, see Figs. 5.4, 5.5 and 5.6; 5. There are three types of flexible steel socket pipe joint: A-shaped, B-shaped, and C-shaped, as shown in Figs. 5.7, 5.8 and 5.9. 6. Micro-diameter pipes with a diameter less than 800 mm are shown in Figs. 5.10 and 5.11 (Tables 5.5, 5.6 and 5.7).

Fig. 5.2 Rigid joint flat face pipe

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5 Pipe for Pipe Jacking

Fig. 5.3 Rigid joint tongue-and-groove pipe

Fig. 5.4 Flexible joint tongue-and-groove pipe

5.4.2 Mark: The marking form is: product code, external pressure load level, nominal inner diameter × effective length, standard number. For example, the Class II reinforced concrete pipe used for jacking construction has an inner diameter of 1200 mm and a length of 3000 mm, the standard number is JC/T 640-2010, it is marked as DPCPII 1200 × 3000 JC/T 640-2010. 5.4.3 Pipe production requirements 1. The concrete strength grade of reinforced concrete pipes for pipe jacking shall not be lower than C50, and the impermeability grade shall not be lower than S8; 2. The cement performance should meet the requirements of “Common Portland cement” (GB 175-2007), “Sulfate resistant Portland cement” (GB748-2005), and “Sulphoaluminate cement” (GB 20472-2006);

5.4 Reinforced Concrete Pipe

29

Fig. 5.5 Flexible joint double socket pipe

Fig. 5.6 Flexible joint steel socket and spigot pipe

3. The fine aggregate should be medium-coarse sand with a fineness modulus of 2.3–3.3; the maximum particle size of the coarse aggregate shall not be greater than 1/3 of the pipe wall thickness, and shall not be greater than 3/4 of the net spacing of the circumferential steel bars; properties of aggregate shall meet the requirements of “Sand for construction” (GB/T 14684-2011) and “Pebble and crushed stone for building” (GB/T 14685-2011); 4. The steel bars should be HPB235, HRB335, HRB400 steel bars, and the performance of steel bars should be in accordance with “Cold rolled ribbed steel bars” (GB 13788-2008), “Steel for the reinforcement of concrete—Part 1: hot rolled plain bars” (GB 1499.1-2008), “Steel for the reinforcement of concrete—Part 2: hot rolled ribbed bars” (GB 1499.2-2007), “Cold-drawn low-carbon wire for concrete products” (JC/T540-2006);

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5 Pipe for Pipe Jacking

Fig. 5.7 A-shaped steel socket pipe with flexible joint

Fig. 5.8 B-shaped steel socket pipe with flexible joint

5. The spacing of circumferential steel bars of steel frame shall be determined by design calculation, and shall not be greater than 150 mm, the diameter of the steel bars should not be less than 4.0 mm, and the circumferential steel bars at both ends of steel frame shall be tightly wrapped around 1–2 circles; 6. The diameter of the longitudinal steel bars of the steel frame shall not be less than 4.0 mm, the circumferential spacing of the longitudinal steel bars shall not be greater than 400 mm, and the number of longitudinal bars shall not be less than 6; 7. For pipes with a nominal inner diameter less than or equal to 1000 mm, singlelayer reinforcement can be used, and the reinforcement position is 2/5 from the

5.4 Reinforced Concrete Pipe

Fig. 5.9 C-shaped steel socket pipe with flexible joint

Fig. 5.10 Micro-diameter reinforced concrete pipe joint

Fig. 5.11 Micro-diameter reinforced concrete pipe

31

84

185

2200

72

235

2800

120

128

140

250

265

290

3000

3200

3500

112

90

104

200

220

2400

2600

80

150

170

1800

66

140

1650

2000

60

64

125

135

57

1500

117

1400

55

48

44

1600

100

115

1200

1350

95

1100

40

37

75

85

900

33

70

Effective Class I Pipe length L ≥ Wall Crack (mm) thickness t load ≥ (mm) (kN/m)

1000

800

Nominal inner diameter D0 (mm)

210

192

180

168

156

140

130

120

110

99

96

90

86

83

72

66

60

56

50

Failure load (kN/m) 0.06

Internal water pressure (MPa)

320

290

275

255

235

230

220

200

180

165

160

150

140

135

120

110

100

90

80

Wall thickness t ≥ (mm)

Class II Pipe

231

211

198

185

172

152

145

134

120

110

106

99

93

90

81

74

69

61

54

Crack load (kN/m)

347

317

300

280

260

230

220

200

180

170

159

150

140

135

120

110

100

92

81

Failure load (kN/m) 0.10

Internal water pressure (MPa)

Table 5.4 The inspection index of external load and internal water pressure for reinforced concrete pipe

320

290

275

255

235

230

220

200

180

165

160

150

140

135

120

110

100

100

100

Wall thickness t ≥ (mm)

321

292

273

254

235

217

199

181

162

148

144

135

126

122

107

98

89

80

71

Crack load (kN/m)

Class III Pipe

482

438

410

381

353

326

299

272

243

222

216

203

189

183

161

147

134

120

107

Failure load (kN/m)

0.10

Internal water pressure (MPa)

32 5 Pipe for Pipe Jacking

5.4 Reinforced Concrete Pipe

33

Table 5.5 Parameters of micro-diameter reinforced concrete pipe (mm) No Nominal Wall Effective L1 S pipe thickness length L diameter D T 1

300

65

2

400

70

1000

LC

LC1 LC2 t

51 1.5 120 70

50

D1

DC

1.5 410 425 520 535

3

500

86

652 667

4

600

87

750 768

5

700

88

6

800

100

Remark

81 2.5 170 90

80

2.0 852 870 976 994

Table 5.6 Dimension deviation of steel socket of micro-diameter reinforced concrete pipe (unit: mm) Nominal pipe diameter D

Perimeter

Length Lc

Wall thickness T

250–500

+4 −2

±2

+ 0.15

600–700

+6 −3

800–1000

±2

+ 0.2

±3

+ 0.2

Table 5.7 Inspection index of external load and internal water pressure of micro-diameter reinforced concrete pipe Nominal inner diameter D (mm)

Pipe wall thickness T (mm)

Crack load (kN/ m)

Failure load (kN/ m)

Internal water pressure (MPa)

300

65

27

41

0.1

400

70

35

53

500

86

44

68

600

87

53

80

700

88

62

93

800

100

71

107

inner wall of the pipe; for pipes with a nominal inner diameter of greater than 1000 mm, double-layer reinforcement should be used; 8. The number of circumferential steel bars should be increased within the range of 200–300 mm at pipe end, and “U”-shaped stirrups or other forms of reinforcing ribs should be configured; 9. Thickness of steel plate for steel socket: pipe with nominal diameter of greater than or equal to 2000 mm, the thickness of steel plate should not be less than 10 mm; pipe with nominal diameter of less than 2000 mm and greater than or equal to 1200 mm, the thickness of steel plate should not be less than 8 mm; pipe with nominal diameter of less than or equal to 1200 mm, the thickness of the steel plate should not be less than 6mm;

34

5 Pipe for Pipe Jacking

10. The performance of the socket steel plate and the spigot special-shaped steel should meet the requirements of “Hot-rolled plates and strips of carbon structural steel and high strength low alloy structural steel” (GB/T 3274-2007), “Carbon structural steel” (GB/T 700-2006). 5.4.4 Appearance quality inspection 1. The inner and outer surfaces of pipe should be smooth, and the pipe body should be free of sticky skin, pitted surface, honeycomb, sag, exposed ribs, hollowing, and the depth of local pits should not be greater than 5 mm. The surface roughening and micro pores produced by core die vibration and radial extrusion process can be left untreated; 2. The outer surface of the pipe is not allowed to have cracks, and the crack width on the inner surface shall not exceed 0.05mm, but the surface cracks and the drying shrinkage of the mortar layer are not subject to this limit; 3. The end face, double sockets, and the outer surface of socket of the steel spigot pipe should be flat; 4. There shall be no slurry leakage at the pipe joints. 5.4.5 Pipes are allowed to be repaired under the following conditions 1. The surface concave depth does not exceed 10 mm, the depth of the sticky skin, pitted surface, and honeycomb does not exceed 1/5 of the wall thickness, the maximum depth does not exceed 10mm, and the total area does not exceed 1/20 of the corresponding inner or outer surface, each area no more than 100 cm2 ; 2. There is partial collapse on the inner surface, but the collapsed area does not exceed 1/20 of the internal surface area of pipe, and the area of each piece does not exceed 100 cm2 ; 3. The depth of grout leakage at the joints does not exceed 1/5 of the wall thickness, and the maximum length does not exceed 1/5 of the pipe length; 4. The longitudinal length of the end face collision shall not exceed 100 mm, and the limit of the circumferential length shall not exceed the regulations in Table 5.8. 5.4.6 Allowable deviation of dimension Table 5.8 Limit of circumferential length of end face collision (unit: mm) Nominal inner diameter of pipe D3

Circumferential length limit for bumps

100–200

45

300–500

60

600–900

80

1000–1600

105

1650–2400

120

2600–3000

150

3200–3500

200

5.4 Reinforced Concrete Pipe

35

1. Socket steel pipe with flexible joint: see Table 5.9 for the allowable deviation of dimension. 2. Tongue and groove pipe with flexible joint: see Table 5.10 for the allowable deviation of dimension. 3. Double sockets pipe with flexible joint: see Table 5.11 for the allowable deviation of dimension. Table 5.9 Allowable deviation of dimension for socket steel pipe with flexible joint Nominal inner diameter (mm)

Pipe dimension (mm)

Socket dimension (mm)

D0

t

L

D1

D2

D3

L1

L2

600–800

+4 −8

+8 −2

+ 18 − 10

±2

±2

±2

±3

±2

900–1500

+6 − 10

+ 10 −3

+ 18 − 12

±2

±2

±2

±3

±2

1600–2400

+8 − 12

+ 12 −4

+ 18 − 12

±2

±2

±2

±3

±2

2600–3500

+ 10 − 14

+ 14 −5

+ 18 − 12

±2

±2

±2

±3

±2

Table 5.10 Allowable deviation of dimension for tongue & groove pipe with flexible joint Nominal inner diameter (mm)

Pipe dimension (mm)

Socket dimension (mm)

D0

t

L

D1

D2

D3

L1

L2

1350–1500

+6 − 10

+ 10 −3

+ 18 − 12

±2

±2

±2

±3

+4 −3

1600–2400

+8 − 12

+ 12 −4

+ 18 − 12

±2

±2

±2

±3

+4 −3

2600–3000

+ 10 − 14

+ 14 −5

+ 18 − 12

±2

±2

±2

±3

+4 -3

Table 5.11 Allowable deviation of dimension for double sockets pipe with flexible joint Nominal inner diameter (mm)

Pipe dimension (mm)

Socket dimension (mm)

D0

t

L

D1

D2

L1

600–800

+4 −8

+8 −2

+ 18 − 10

±2

±2

±3

900–1500

+6 − 10

+ 10 −3

+ 18 − 12

±2

±2

±3

1600–2400

+8 − 12

+ 12 −4

+ 18 − 12

±2

±2

±3

2600–3000

+ 10 − 14

+ 14 −5

+ 18 − 12

±2

±2

±3

36

5 Pipe for Pipe Jacking

4. Steel socket and spigot pipe with flexible joint: see Table 5.12 for the allowable deviation of dimension. 5. Flat pipe with rigid joint: see Table 5.13 for the allowable deviation of dimension. 6. Tongue and groove pipe with rigid joint: see Table 5.14 for the allowable deviation of dimension. 5.4.7 Pipe section curvature: the allowable deviation is less than or equal to 0.3% of the effective length of the pipe.

Table 5.12 Allowable deviation of dimension for steel socket and spigot pipe with flexible joint Pipe dimension (mm)

Socket dimension (mm)

D0

t

L

D1

D2

D3

L1

L2

300–800

+4 –8

+8 –2

+ 18 –10

±2

±2

±2

±3

±2

900–1500

+6 –10

+ 10 –3

+ 18 –12

±2

±2

±2

±3

±2

1600–2400

+8 –12

+ 12 –4

+ 18 –12

±2

±2

±2

±3

±2

2600–3200

+ 10 –14

+ 14 –5

+ 18 –12

±2

±2

±2

±3

±2

Nominal inner diameter (mm)

Table 5.13 Allowable deviation of dimension for flat pipe with rigid joint

Nominal inner diameter (mm)

Pipe dimension (mm) D0

t

L

250–800

+4 −8

+8 −2

+ 18 − 10

900–1500

+6 − 10

+ 10 −3

+ 18 − 12

1600–2400

+8 − 12

+ 12 −4

+ 18 − 12

Table 5.14 Allowable deviation of dimension for tongue and groove pipe with rigid joint Nominal inner diameter (mm)

Pipe dimension (mm)

Socket dimension (mm)

D0

t

L

D1

D2

D3

L1

L2

1100–1500

+6 –10

+ 10 –3

+ 18 –10

±3

±3

±3

±3

±3

1650–1800

+8 –12

+ 12 –4

+ 18 –12

±3

±3

±3

±4

±4

2000–2400

+8 –12

+ 12 –4

+ 18 –12

±3

±3

±3

±5

±5

2600–3000

+ 10 –14

+ 14 –5

+ 18 –12

±3

±3

±3

±6

±6

5.4 Reinforced Concrete Pipe Table 5.15 Allowable error of ovality (mm)

37

Diameter

Ovality

300 ≤ D ≤ 600

2

600 < D < 1200

3

1200 ≤ D < 3000

4

3000 ≤ D

5

5.4.8 The ovality of the pipe section shall meet the requirements in Table 5.15. 5.4.9 Internal water pressure test: When conducting internal water pressure inspection, wetted surfaces are allowed under the specified test pressure, but the area of wetted surfaces shall not be greater than 5% of the total external surface area, and there shall be no water droplets flowing. Storm sewer pipes with a wall thickness greater than or equal to 150 mm may not be subject to internal water pressure inspection. 5.4.10 External pressure load: not less than the load requirements specified in Tables 5.4 and 5.7. 5.4.11 The thickness of the inner and outer concrete protective layer of the circumferential reinforcement: when the wall thickness is greater than 50 mm and less than or equal to 100 mm, it should not be less than 15 mm; when the wall thickness is greater than 100 mm, it should not be less than 20 mm; for pipes with special anti-corrosion requirements, the thickness of the protective layer should be determined as required. 5.4.12 Factory inspection 1. The inspection items are divided into A-type indicators and B-type indicators, including appearance quality, dimensional deviation (excluding the thickness of the protective layer), and physical and mechanical properties, see Table 5.16. 2. Batch rules: pipes with the same specification, the same joint type, and the same external load level produced by the same material and the same production process form a batch under inspection. The batch numbers of different pipe diameters are shown in Table 5.17. If the total production within 3 months is insufficient, it shall also be used as an inspection batch. 3. Sampling inspection scheme (1) Appearance quality, randomly sample 10 pipes from the inspected batch, and conduct appearance quality inspection one by one; (2) Dimension deviation, randomly sample 10 pipes from the inspected batch, and carry out dimensional deviation inspection one by one; (3) Internal and external load, two pipes are selected from the pipes that have passed the inspection of appearance quality and dimensional deviation, one is tested for internal water pressure, and the other is tested for external pressure crack load.

38

5 Pipe for Pipe Jacking

Table 5.16 Pipe inspection items and categories No

Quality index

Test items

Category

1

Appearance quality

Sticky skin

B

2

Pitting surface

B

3

Local pit

B

4

Honeycomb

A A

5

Collapse

6

Exposed reinforcing bars A

7

Hollowing

A

8

Crack

A

9

Joint leakage

A

10

End face collision

A

Socket diameter (D3 )

A

12

Spigot diameter (D1 )

A

13

Socket length (L1 )

A

11

Size deviation

14

Spigot length (L2 )

A

15

Nominal inner diameter of pipe (D0 )

A

16

Pipe wall thickness (t)

A

17

Effective length of pipe section (L)

A

18

Curvature (δ)

A

19

End face incline (S)

A

20

Thickness of protective layer (C)

A

Internal water pressure

A

21 22

Physical and mechanical properties

23 Table 5.17 Factory inspection batch

Remarks

Crack load

A

Failure load

A

D1 for socket and spigot pipe rigid joint L1 for socket and spigot pipe rigid joint

Nominal inner diameter D0 (mm) Batch (number) Remarks 250–500

≤ 2500

600–1400

≤ 2000

1500–2200

≤ 1500

2400–3500

≤ 1000

5.4 Reinforced Concrete Pipe

39

4. Decision rules (1) Appearance quality and dimension deviation. Among the 10 inspected pipes, all A items must be qualified, no more than two pipes are out of tolerance in each B item and no more than two B items are out of tolerance, then the appearance quality and dimensional deviation of products from this batch are qualified; (2) When the mechanical properties, internal and external load inspection meet the requirements of Tables 5.4 and 5.7, the mechanical properties of products from this batch are qualified. If the internal or external load inspection does not meet the requirements, it is allowed to extract 2 pipes from the same batch of products for re-inspection. If all the re-inspection results meet the standard requirements, the original unqualified pipe will be rejected and the products from this batch are qualified. If there is still one pipe that does not meet the standard requirements in re-inspection, then the mechanical properties of products from this batch are unqualified. 5. General decision: When the appearance quality, dimensional deviation, and mechanical properties all meet the requirements of the standard, the products from this batch are qualified. 6. When the users have doubts about the product quality, they have the right to re-inspect the pipe delivered for use in cooperation with the pipe manufacturer. If the re-inspection is unqualified, the inspection fee shall be paid by the pipe manufacturer; if the re-inspection is qualified, the inspection fee shall be paid by the user. 5.4.13 Mark, package, transportation, storage and delivery certificate of pipe 1. Mark: The surface of each pipe should be marked with: company name, trademark, production license number, product mark, production date, and marked with “no collision” sign. 2. Package: In order to prevent damage to the pipe during transportation, both ends of the pipe section can be wrapped with soft materials. 3. Transportation: During loading and unloading, free rolling and throwing are not allowed, and pipes should be lightly lifted and dropped. It is strictly prohibited to hoist directly the pipe with steel wire rope through it. Collision is also strictly prohibited during transportation. 4. Storage: It should be stacked separately according to the variety, specification, external load level and production date. The stacking site should be flat, and the number of stacking layers should not exceed the calibration in Table 5.18. Table 5.18 Stacking layers of pipes Nominal inner diameter D0 (mm)

300–600

700–900

1000–1400

1500–1800

≥ 2000

Stacked layers

5

4

3

2

1

40

5 Pipe for Pipe Jacking

5. Factory certificate: When the pipes leave the factory, the factory certificate with the uniform number should be accompanied, and its contents should include: enterprise name, trademark, production date, implementation standard, production license mark and number, product variety, specification, load level, etc. 5.4.14 Pipe joint sealing 1. 1 The sealing of pipe joints shall meet the following requirements: (1) The normal progress of pipe jacking construction shall be ensured; (2) The pipe section and the tool pipe or the pipe jacking machine should be able to connect normally; (3) Appropriate methods should be adopted to prevent the pipeline from rotating; (4) After the pipeline is penetrated through, the joint should be sealed. 2. When using a rubber ring waterproof joint, the following requirements should be met: (1) The joint surface of pipe section should be smooth and flat, free of honeycombs, pits, pores, cracks, missing edges and corners, etc., and the joint size should comply with the regulations; (2) The rubber ring dimension should meet the design requirements, and the appearance should be compact and uniform, without defects such as cracks, pores or dents; (3) The rubber ring should be kept clean, free of oil, mud, sand, etc. on the surface, and should not be exposed to sunlight; (4) The weld line of the steel collar should be flat, the ribs should be perpendicular to the plane of the steel plate, and the surface should be treated with anti-corrosion. 3. The use of pipe joint sealing materials should also meet the requirements in Table 5.19. 4. Sealing rubber ring for pipe joint (1) The sealing rubber ring material should meet the requirements of “Rubber seals—joint ring for water supply, drainage and sewerage pipelines—specification for materials” (GB/T 21873-2008); Table 5.19 Sealing material size and installation requirements Sealing material

Binder

Joint width b (mm)

Min 10

Joint depth t (mm)

Single layer t ≥ 12 + b/3

Joint surface

Dry (humidity < 5%), no oil, no dust

Rubber liner Double layer t ≥ 2(12 + b/3)

Smooth surface, no protrusions, no pits

t ≥ 2b

5.5 Fiberglass Pipe

41

(2) Single rubber ring can be used for non-pressure drainage pipe joint; (3) Double rubber rings should be used for pressurized water pipe joint; (4) The cross-sectional shape of the sealing rubber ring should be “L” shape, tooth shape, wedge shape or semicircle and semisquare; (5) For micro-diameter pipes, an integral buffer water-blocking rubber ring should be used; (6) When encountering oily groundwater, nitrile rubber should be used; when it contains weak acid and weak alkali groundwater, chloroprene rubber should be used; when it is eroded by mold, it is better to use rubber with two or more mildew resistance level; where the average temperature is low, EPDM rubber should be used; (7) With butt joint for pipe connection, lubricating materials should be used on the surface of the rubber ring. White oil or detergent should be used as the lubricating material. In order to prevent the sealing rubber joints from aging, butter or engine oil should not be used. 5. Buffer wood washer (1) Wood washers should be made of pine, fir or plywood with uniform and elastic texture; (2) The compressive modulus of wood washers should not be greater than 140 MPa; (3) The thickness of the wood washer should be determined according to the pipe diameter and the curvature radius of the pipe, and should be compatible with the design jacking force, the thickness is usually 10–30 mm; (4) The outer diameter of the wood washer should be flush with the groove of the rubber sealing ring, and the inner diameter should be 20 mm larger than the inner diameter of the pipe; (5) Wood washers should be pasted on the force transmission surface of the pipe section with adhesive. 5.4.15 The maximum allowable jacking force of pipe section is shown in Table 5.20.

5.5 Fiberglass Pipe 5.5.1 Classification 1. According to production process, glass fiber pipes (including glass fiber reinforced plastic sandy pipes and resin concrete pipes) are divided into: fixed-length winding: on a pipe mold with a certain length, the glass fiber is wound layer by layer from the inside to the outside to form a pipe, Code “I”; centrifugal casting: cast glass fiber, resin, quartz sand, etc. into a rotating mold, and to form a pipe

42

5 Pipe for Pipe Jacking

Table 5.20 Reference value of allowable jacking force of pipe section Pipe inner diameter D0 (mm)

Pipe wall thickness t (mm)

Flexible steel socket pipe

Allowable pipe jacking force (kN) Flexible double Flexible socket pipe tongue and groove pipe

Rigid tongue and groove pipe

300

65

300

–

–

–

400

70

350

–

–

–

500

86

400

–

–

–

600

87

480

–

–

–

700

88

740

–

–

–

800

100

1000

–

–

–

900

100

1400

–

–

–

1000

100

1600

1600

–

–

1100

110

2100

2100

–

1700

1200

120

2600

2600

–

2000

1350

135

3300

3300

2900

2600

1400

140

3800

3800

3000

2800

1500

150

4200

4200

3300

3200

1600

160

5200

5200

3400

3600

1650

165

5300

5300

3500

3900

1800

180

6400

6400

4300

4600

2000

200

7900

7900

5200

5700

2200

220

9800

9800

6600

6900

2400

230

11,000

11,000

7500

7800

2600

235

12,300

12,300

8200

8600

2800

255

14,000

14,000

9500

9900

3000

275

17,100

17,100

11,300

11,400

3200

290

20,600

–

–

–

3500

320

25,400

–

–

–

after curing, code “II”; continuous winding: on a continuous output mold, the resin, continuous fiber, chopped fiber and quartz sand are continuously laid by the hoop winding, then cut into a certain length of pipe after curing, code-named “III”. 2. Axial compressive strength grades (MPa): 65, 75, 90, 105. 3. Pressure rating (MPa): 0.10, 0.25, 0.40, 0.60, 0.80, 1.00. 4. Stiffness grade (N/m2 ): 15,000, 20,000, 30,000, 50,000, 100,000.

5.5 Fiberglass Pipe

43

5.5.2 Mark Marking form: product code–production process–nominal diameter–compressive strength class–pressure class–standard number of rigidity class. Example: The glass fiber reinforced plastic pipe used for pipe jacking construction adopts fixed-length winding process, nominal diameter 2000 mm, combination of axial compressive strength grade of 65 MPa and 105 MPa, pressure grade of 0.25 MPa, stiffness grade of 20,000 N/m2 , marked as GRP JP-I-2000-65(105)-0.25-20000 GB/T 21492-2008.

5.5.3 Pipe Production Requirements 1. Lining resin: The hygienic index of the resin lining used for water supply and drinking water pipes must meet the requirements of “Hygienic standard for unsaturated polyester resin and glass fiber reinforced plastics used as food containers and packaging materials” (GB 13115-1991). The anti-corrosion index of lining resin for the transportation of corrosive media must meet the following anti-corrosion requirements: (1) For fixed-length winding and continuous winding processes, the mechanical properties of the lining resin should meet the following requirements: tensile strength: ≥ 60 MPa; tensile modulus of elasticity: ≥ 2.50 GPa; elongation at break: ≥ 3.5%; thermal deformation temperature: ≥ 70 °C; (2) For the centrifugal casting process, the mechanical properties of the lining resin should meet the following requirements: tensile strength: ≥ 10 MPa; elongation at break: ≥ 15%. 2. Structural resin: The resin used should meet the requirements of “Liquid unsaturated polyester resin for fiber reinforced plastics” (GB/T 8237–2005), “Bisphenol-A epoxy resin” (GB/T 13657-2011) and the corresponding national standards or the industry standard, the mechanical properties of the resin casting body should meet the following requirements: tensile strength: ≥ 60 MPa; tensile modulus: ≥ 3.0 GPa; elongation at break: ≥ 2.5%; thermal deformation temperature: ≥ 70 °C. 3. Glass fiber: alkali-free glass fiber and its products should be used and meet the requirements of the corresponding national standards or industry standards. 4. Quartz particles: quartz particles should be made of high-quality silica sand, with SiO2 content (mass percentage) not less than 95%, and water content (mass percentage) not more than 0.25%.

44

5 Pipe for Pipe Jacking

5.5.4 Appearance Quality Inspection 1. The pipe inner surface should be smooth and flat, free of cracks, delamination, bubbles, pinholes, cracks, depressions, blisters, foreign inclusions and poor glue areas that affect the performance. 2. There are no cracks, delamination, bubbles, cracks, foreign inclusions and poor glue areas on pipe outer surface. 3. The pipe end face should be flush, the edges and cutting parts should be coated with resin sleeves, and all parts should be free of burrs.

5.5.5 Allowable Deviation of Dimension 1. The length deviation of pipe section shall meet the requirements of Table 5.21. 2. The pipe wall is composed of an inner lining layer and a structural layer. The thickness of the inner lining layer should not be less than 1.2 mm. The thickness of the structural layer is determined by the designer. Average thickness of pipe wall at any section of pipe body shall not be less than the larger thickness specified in Table 5.22 and the design, and the minimum pipe wall thickness shall not be less than 90% of the design thickness. 5.5.6 Pipe hardness: The Barcol hardness of pipe outer surface layer should not less than 4.0. 5.5.7 Mechanical properties 1. Initial axial compressive strength: The same pipe can be composed of one or two materials with different initial axial compressive strength, and its initial axial compressive strength should not be less than the value of corresponding axial compressive strength grade. 2. The initial circumferential tensile strength of pipe section shall not be less than the value specified in Table 5.23. 3. The initial axial tensile strength of pipe section shall not be less than the value specified in Table 5.24. Table 5.21 Length deviation of pipe section

Length (mm)

Deviation

2000

± 10

2500

± 12

3000

± 15

4000

± 20

6000

± 30

5.5 Fiberglass Pipe

45

Table 5.22 Wall thickness Nominal diameter (mm)

Minimum wall thickness (mm)

Nominal diameter (mm)

Minimum wall thickness (mm)

400

15

1600

40

500

16

1800

45

600

17

2000

50

700

19

2200

55

800

21

2400

60

900

24

2600

65

1000

25

2700

70

1200

30

3000

75

1400

35

Table 5.23 Initial circumferential tensile strength Nominal diameter (mm)

Pressure grade (MPa) ≤ 0.25

0.4

0.6

0.8

1.0

400

315

504

758

1008

1260

500

394

630

845

1260

1575

600

473

756

1134

1512

1890

700

551

882

1323

1764

2205

800

620

1008

1512

2016

2520

900

709

1134

1701

2268

2835

1000

798

1260

1800

2520

3150

1200

954

1513

2288

3024

3780

1400

1103

1764

2646

3528

4410

1600

1360

2016

3024

4032

5040

1800

1418

2268

3402

4536

5670

2000

1575

2520

3780

5040

6300

2200

1733

2772

4158

5544

6930

2400

1890

3024

4536

6048

7560

2600

2048

3275

4914

6552

8190

2800

2205

3523

5292

7056

8820

3000

2353

3780

5570

7560

9450

4. The initial ring stiffness of pipe section shall not be less than the value of the corresponding stiffness grade, and the minimum stiffness grade of pipe sections with different nominal diameters shall meet the requirements of Table 5.25. 5. Initial flexibility: The initial flexural level A and flexural level B of each sample of pipe section shall meet the requirements of Table 5.26 at the same time.

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5 Pipe for Pipe Jacking

Table 5.24 Initial axial tensile strength Pressure grade (MPa)

Nominal diameter (mm)

≤ 0.4

0.6

0.8

1.0

400

105

130

145

160

500

115

150

170

190

600

125

165

193

220

700

135

180

215

250

800

150

200

240

280

900

165

215

263

310

1000

185

230

285

340

1200

205

260

320

380

1400

225

290

355

420

1600

250

320

390

460

1800

275

360

425

500

2000

300

380

460

540

2200

325

410

495

580

2400

350

440

530

620

2600

375

470

565

660

2800

400

505

605

705

3000

430

540

645

750

Table 5.25 Minimum stiffness level requirements

Nominal diameter (mm)

  Minimum stiffness level N/m2

400

50,000

500–600

30,000

700–1000

20,000

1200–3000

15,000

Table 5.26 Radial deformation rate and requirements of initial flexibility   Flexural level (mm) Stiffness level N/m2 15,000

20,000

30,000

50,000

10,000

Requirement

A(%)

6.6

6.0

5.1

4.2

3.3

No crack in pipe inner wall

B(%)

11.0

10.0

8.5

7.0

5.5

The pipe wall structure has no delamination, no fiber fracture and yield

5.5 Fiberglass Pipe

47

5.5.8 Water leakage: For pipes with a pressure rating of not less than 0.25 MPa, apply a hydrostatic internal pressure of 1.5 times the pressure rating and keep the pipes without leakage for 2 min. 5.5.9 Factory inspection 1. Inspection items include appearance quality, dimension, Barcol hardness, mechanical properties (initial axial compressive strength, initial circumferential tensile strength, initial axial tensile strength, initial ring stiffness, initial flexibility) and hydraulic leakage. 2. Sampling inspection scheme: (1) Each pipe should be inspected for appearance quality, dimension (not including lining thickness), and Barcol hardness; (2) 300 pieces are used as a batch, and less than 300 pieces are treated as a batch. 4 pieces are randomly selected from each batch for hydraulic leakage inspection, and 1 piece is randomly selected for inspection of lining thickness and mechanical properties. 3. Decision rules: (1) Appearance quality, dimension (not including lining thickness) and Barcol hardness meet the corresponding requirements, and the corresponding items are decided to be qualified; otherwise, the product is unqualified; (2) The four water leakage tests meet the requirements, and the batch of products is decided to be qualified. If the water leakage is unqualified, the water leakage test is carried out one by one, and the pipe is qualified if it meets the requirements; (3) When the lining thickness and mechanical properties meet the requirements, the lining thickness and mechanical properties of the batch of products are decided to be qualified; if there are more than 2 unqualified items, then double the sampling inspection of unqualified items in the same batch of products, if there are still unqualified items, the batch of products will be decided as unqualified. 4. When the users have doubts about the product quality, they have the right to re-inspect the pipe delivered for use in cooperation with pipe manufacturer. If the re-inspection is unqualified, the inspection fee shall be paid by the pipe manufacturer; if the re-inspection is qualified, the inspection fee shall be paid by the user. 5.5.10 Mark, package, transportation, storage and delivery certificate of pipe 1. Mark: The surface of each pipe should be marked with durability, the sign should not damage the pipe wall, and the writing should be kept clear during normal loading, unloading and installation. The logo should include: company name, trademark, product mark, batch number, product number, and production date. 2. Package: Before shipment, flexible package such as foamed plastic film should be used to package the pipe end face and outer connecting face at both pipe ends.

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5 Pipe for Pipe Jacking

Table 5.27 Maximum stacking layers of pipes Nominal diameter (mm)

400

500

600–700

800–1200

≥ 1400

Stacking layers

5

4

3

2

1

The width of the package should be 100 mm larger than the width of the pipe outer connecting surface. 3. Transport (1) Flexible ropes should be used for hoisting. If iron chains or steel ropes are used, rubber or other flexible objects must be lined on the contact surface; (2) Double-point hoisting must be used, single-point hoisting is strictly prohibited; (3) When loading and transporting, it should be handled with care and throwing is strictly prohibited; (4) Horizontal stacking should be used during transportation, and should be firmly fixed; (5) During transportation, loading and unloading, it should not be subject to severe impact. 4. Storage (1) It should be stacked according to types, specifications and grades; (2) The stacking site should be level, and the stacking site should be far away from heat sources, and it is not suitable for long-term storage in the open air; (3) The number of stacked layers should not exceed the value in Table 5.27. 5. When the pipe leaves the factory, it should be accompanied by a certificate of delivery, and its content should include: the name of the manufacturer, trademark, product specifications, and date of production. 5.5.11 The jacking force of pipe section is based on the minimum pipe wall thickness. Table 5.28 shows the allowable jacking force of pipe section. If the allowable jacking force needs to be increased, the pipe wall thickness should be increased.

5.6 Prestressed Steel Cylinder Concrete Pipe 5.6.1 Steel cylinder concrete pipe is made of a concrete core pipe with a steel cylinder wound ring prestressed steel wire and a protective layer of cement mortar on the outside. 5.6.2 Classification 1. According to the position of core pipe, it can be divided into:

5.6 Prestressed Steel Cylinder Concrete Pipe

49

Table 5.28 Allowable jacking force of pipe section Nominal diameter (mm)

Allowable jacking force (kN)

Nominal diameter (mm)

Minimum wall thickness (kN)

400

269

1600

3827

500

383

1800

4844

600

517

2000

5980

700

737

2200

7236

800

918

2400

8612

900

1294

2600

10,107

1000

1556

2800

11,721

1200

2153

3000

13,456

1400

2930

(1) Lining prestressed steel cylinder concrete pipe: a core pipe composed of a steel cylinder and a concrete lining, a ring prestressed steel wire is wound on the outside of the steel cylinder, and then covered with a protective layer of cement mortar, code-named “PCCPI”. Usually, this kind of pipe is not used in pipe jacking construction; (2) Embedded prestressed steel cylinder concrete pipe: a core pipe composed of a steel cylinder and concrete layers on the inner and outer sides of the steel cylinder, and a ring prestressed steel wire is wound on the outer side of the core pipe concrete, and then covered with a protective layer of cement mortar, code named “PCCPE”. It is a kind of pipe that can be used for the pipe jacking (see Fig. 5.12). 2. According to the joint sealing form, it can be divided into: (1) Single rubber ring prestressed steel cylinder concrete pipe: The pipe joint adopts a single rubber seal ring for flexible sealing connection of the prestressed steel cylinder concrete pipe. The code named of “PCCPSE” (see Fig. 5.13). (2) Double rubber ring prestressed steel cylinder concrete pipe: The pipe joint adopts two rubber sealing rings for flexible sealing connection of prestressed steel cylinder concrete pipe, code named “PCCPDE” (see Fig. 5.14).

Fig. 5.12 Outline drawing of embedded steel cylinder concrete pipe (PCCPE)

50

5 Pipe for Pipe Jacking

Fig. 5.13 Single rubber ring embedded steel cylinder concrete pipe (PCCPSE) joint diagram

Fig. 5.14 Double rubber ring embedded steel cylinder concrete pipe (PCCPDE) joint diagram

5.6.3 Specifications: The basic dimensions of the embedded prestressed concrete cylinder pipe (PCCPL) are shown in Tables 5.29 and 5.30. 5.6.4 Marking form: product code nominal diameter × effective length/P working pressure/H standard number of overburden depth. Example: A prestressed steel cylinder concrete pipe with a double rubber ring embedded in a nominal inner diameter of 4000 mm, an effective length of 6000 mm, a working pressure of 1.6 MPa, and a covered depth of 6 m is marked as follows: PCCPDE4000 × 6000/P1.6/H6GB/ T 19685-2005. 5.6.5 Pipe production requirements 1. Rubber ring (1) The rubber sealing ring of pipe joint should be a solid rubber ring with a circular cross section. The size and volume of the rubber ring should match the size and clearance of the rubber groove of socket steel ring. The basic performance and quality requirements of the rubber sealing ring should meet

150

150

165

2600

3343

200

3200

2923

3000

245

260

3800

4000 4183

3973

3553 3763

220

230

3400

3600

3143

175

190

2800

2713

2313 2513

2103

1903

1703

1503

140

1.5

108

Socket face inner diameter Bb

150

20

108

Socket Spigot depth length C E

2200

125

2000

1.5

Steel cylinder thickness Ty

2400

100

115

1600

20

100

1400

1800

Protective Layer thickness tt

Minimum Core thickness t0

Nominal diameter D0

4183

3973

3763

3553

3343

3143

2923

2713

2513

2313

2103

1903

1703

1503

Spigot face outside diameter Bs

25

25

Joint inner clearance J

Table 5.29 The basic size of the embedded pipe (PCCPE) (single rubber ring joint) (unit: mm)

25

25

Joint outer clearance K

20

20

5000 6000

5000 6000

Rubber Effective ring length L0 diameter d

5125 6125

5083 6083

9.67

8.69

7.77

7.05

6.07

5.44

4.72

4.16

3.53

3.05

2.52

2.11

1.67

1.48

Pipe Referential total weight (t/ length m) L

5.6 Prestressed Steel Cylinder Concrete Pipe 51

150

150

165

2600

3343

200

3200

2923

3000

245

260

3800

4000 4183

3973

3553 3763

220

230

3400

3600

3143

175

190

2800

2713

2313 2513

2103

1903

1703

1503

140

1.5

108

Socket face inner diameter Bb

150

20

108

Socket Spigot depth length C E

2200

125

2000

1.5

Steel cylinder thickness Ty

2400

100

115

1600

20

100

1400

1800

Protective layer thickness tt

Minimum core thickness t0

Nominal diameter D0

4183

3973

3763

3553

3343

3143

2923

2713

2513

2313

2103

1903

1703

1503

Spigot ace outside diameter Bs

25

25

Joint inner clearance J

Table 5.30 The basic size of the embedded pipe (PCCPE) (double rubber ring joint) (unit: mm)

25

25

Joint outer clearance K

20

20

5000 6000

5000 6000

Rubber Effective ring length L0 diameter d

5135 6135

5135 6135

9.67

8.69

7.77

7.05

6.07

5.44

4.72

4.16

3.53

3.05

2.52

2.11

1.67

1.48

Pipe Referential total weight (t/ length m) L

52 5 Pipe for Pipe Jacking

5.6 Prestressed Steel Cylinder Concrete Pipe

53

the requirements of “Rubber gasket ring for prestressed and self-stressed concrete pipe” (JC/T 748-2010); (2) The rubber sealing ring is allowed to be spliced, and each rubber sealing ring is allowed to be spliced at most two places, and the distance between the two splicing points should not be less than 600 mm. Inspect each splicing point of the rubber sealing ring one by one. Extend the rubber sealing ring to more than twice its original length and twist it 360° during inspection. Observe the splicing point of the rubber ring with naked eyes. If there is a disconnection or crack, it should be re-spliced or discarded; (3) The rubber sealing ring should be stored in a dry, cool place, away from sunlight. 2. Joint steel ring (1) The socket steel ring should be made of a single steel plate, or multiple steel plates can be used to form steel strips. After the ring is formed by welding, the socket steel ring is expanded to a full circle with an expansion force exceeding the elastic ultimate strength of the steel plate to obtain precise size; (2) The spigot steel ring should be made of special-shaped steel strips. After being welded to form a circular ring, the spigot steel ring shall be expanded to a full circle with an expansion force exceeding the elastic ultimate strength of the steel plate to obtain a precise size; (3) The butt welding seam of the steel ring working surface of the socket joint should be polished smooth and leveled with the adjacent surface. Any cracks, slag inclusions, pores and other defects shall not exist on the surface of the welding seam. 3. Steel cylinder (1) Spiral welding, patchwork welding or reel welding can be used for the production of steel cylinders; butt welding or lap welding can be used for the splicing of steel plates; (2) The socket and spigot steel ring should be assembled at the exact position at two ends of steel cylinder, and the inclination of end surface should meet the requirements of Table 5.33; (3) The welding seam of the steel cylinder can be spiral seam, circumferential seam or longitudinal seam, but “cross”-shaped welding seam is not allowed; (4) The welding seam of steel cylinder for lined prestressed steel cylinder concrete pipe shall be continuous and flat. When using butt welding, the weld bulge height should not be greater than 1.6 mm. When using lap welding, the weld bulge height should not be greater than the steel plate thickness of the steel cylinder plus 1.6 mm. 4. Core pipe: The design strength grade of concrete for pipe making shall not be lower than C50.

54

5 Pipe for Pipe Jacking

5.6.6 The pipe allowable deviation should not exceed the requirements of Table 5.31 5.6.7 The appearance quality requirements are as follows 1. Pipe end: The core pipe concrete at the end of pipe socket and spigot joint should not have defects such as lack of material, corners, holes, etc.; the pipe end face should be flush, the edges and cutting parts should be coated with resin, and all parts should be free of burrs. 2. Surface: There should be no cracks, delamination, bubbles, cracks, foreign inclusions and poor glue areas on the pipe outer surface; and the pipe inner surface should be smooth and flat, and there should be no cracks, delamination, bubbles, pinholes, dents, blisters, foreign inclusions and poor glue areas that affect the performance, there should be no holes or pits with a diameter or depth greater than 10 mm, as well as honeycomb, pitted surface and other non-compactness. 3. Socket steel ring: The working surface of the socket and pigot steel ring should be smooth and clean, and there should be no concrete, cement slurry and other dirt. 4. Pipe outer protective layer: The outer protective layer should not show any hollowing, delamination or peeling. 5. Internal surface cracks: the width of the circumferential cracks or spiral cracks on the inner surface of the pipe should not be greater than 0.5 mm (except for laitance cracks); within 300 mm from the pipe spigot end, the width of the circumferential cracks should not be greater than 1.5 mm; inside the pipe and within the range of the angle of 150° along the parallel line of the longitudinal axis of the pipe, no longitudinally visible cracks with a crack length greater than 150 mm are allowed. 6. External surface cracks: The protective layer of cement mortar covering the surface of the prestressed steel wire is not allowed to have any visible cracks; the width of visible cracks in the protective layer of cement mortar covering the area of the non-prestressed steel wire should not be greater than 0.25 mm. 5.6.8 Anti-cracking internal pressure (P1) inspection 1. During the internal pressure test, press to the inspection crack resistance pressure of the pipe, at least at a constant pressure for 5 min, the pipe body shall not burst, partially bulge or leak, and the cement mortar protective layer in the prestressed area of pipe body shall not appear any crack or peeling phenomenon with length of longer than 300 mm and width of greater than 0.25 mm. 2. See Table 5.32 for the anti-cracking internal pressure value of the prestressed steel cylinder concrete pipe with covered depth of 0.8–2.0 m, working pressure of 0.4–2.0 MPa and soil arc foundation (90°). 5.6.9 Anti-cracking external pressure load (Pc ) inspection 1. The three-point method can be used to test the pipe anti-cracking external pressure load. 2. During the external pressure test, the cement mortar protective layer in the prestressed area of pipe body should not have cracks with length of longer than

±4

±6

±8

±5

±8

± 10

400–1200

3000–4000

Core pipe thickness Tc (mm)

inner diameter D0 (mm)

1400–3000

Nominal diameter

−1

Protective layer thickness Tg (mm)

± 10

±6

Pipe length L (mm)

Table 5.31 Allowable deviation of prestressed steel cylinder concrete pipe

+ 1.0 + 0.2 ±5

±4

− 0.2 − 1.0

Spigot Outer diameter Ba (mm)

Depth C (mm)

Socket Inner diameter Bb (mm)

±5

±4

±3

Length E (mm)

0.5% or 12.7 mm

Ovality of socket

≤ 13

≤9

≤6

Inclination of pipe end face

5.6 Prestressed Steel Cylinder Concrete Pipe 55

56

5 Pipe for Pipe Jacking

Table 5.32 Test value of anti-cracking pressure of embedded finished pipe (P1) Nominal diameter (mm)

Cracking pressure (MPa) 0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

1200

0.88

1.16

1.44

1.72

2.00

2.28

2.56

2.84

3.12

1400

0.90

1.18

1.46

1.74

2.02

2.30

2.58

2.86

3.14

1600

0.92

1.20

1.48

1.76

2.04

2.32

2.60

1.88

3.16

1800

0.94

1.22

1.50

1.78

2.06

2.34

2.62

2.90

3.18

2000

0.98

1.26

1.54

1.82

2.10

2.38

2.66

2.94

3.22

2200

1.00

1.28

1.56

1.84

2.12

2.40

2.68

2.96

3.24

2400

1.14

1.42

1.70

1.98

2.26

2.54

2.82

3.10

3.38

2600

1.16

1.44

1.72

2.00

2.28

2.56

2.84

3.12

3.40

2800

1.18

1.46

1.74

2.02

2.30

2.58

2.96

3.14

3.42

3000

1.20

1.48

1.76

2.04

2.32

2.60

2.88

3.16

3.44

3200

1.20

1.48

1.76

2.04

2.32

2.60

2.88

3.16

3.44

3400

1.21

1.49

1.77

2.05

2.33

2.61

2.89

3.17

3.45

3600

1.26

1.54

1.82

2.10

2.38

2.66

2.94

3.22

3.50

3800

1.25

1.53

1.81

2.09

2.37

2.65

2.93

3.21

3.49

4000

1.26

1.54

1.82

2.10

2.38

2.66

2.94

3.22

3.50

Table 5.33 Allowable value of relative rotation angle of pipe joint

Nominal diameter (mm)

Allowable relative angle of pipe joint (°) Single ring joint

Double ring joint

400–1000

1.5

–

1200–4000

1.0

0.5

300 mm and width of more than 0.25 mm or peeling off the cement mortar, and the pipe inner wall should not be cracked. 5.6.10 The allowable relative rotation angle of pipe joint 1. The allowable relative rotation angle of pipe joint shall meet the requirements of Table 5.33. 2. The rotation angle test of pipe connection is to keep the pressure constant for 5 min under the specified pressure, and there should be no leakage of water at pipe connection when the relative rotation angle specified in the standard is reached. 3. When designing the pipe structure, according to the actual situation of the project, the relative angle of pipe joint can be appropriately increased. 5.6.11 Protection of pipes 1. Before the finished pipe is transported to the construction site, the exposed part of the socket and spigot steel ring should be protected by effective anti-corrosion materials.

5.6 Prestressed Steel Cylinder Concrete Pipe

57

2. The anti-corrosion materials for drinking water engineering pipelines shall not have any adverse effects on the water quality in pipelines. 3. When pipelines are used to transport corrosive sewage, seawater or soil environment containing corrosive media, the pipe concrete or cement mortar protective layer should be treated with anti-corrosion treatment. 5.6.12 Pipe repair 1. Crack repair: When the width of the ring or spiral cracks on the pipe inner surface is greater than 0.5 mm, and the width of the ring cracks within 300 mm from the pipe spigot end is greater than 1.5 mm, it should be repaired; the pipe outer surface should be cemented in the non-prestressed area. When the crack width of the mortar protective layer is greater than 0.25 mm, it should be repaired; the pipe body cracks should be repaired with cement slurry or epoxy resin. 2. Core pipe concrete or cement mortar protective layer repair: ➀ The pipe with defects caused by collision during manufacturing and handling process can only be used after qualified repair; ➁ Before repair, the defective concrete or cement mortar should be removed. The cement, cement mortar or non-toxic resin cement mortar used for repair should be the same as the pipe core concrete or cement mortar protective layer; ➂ If the defect surface area of the pipe core concrete before the wire wrapping exceeds the pipe inner surface or 10% of the pipe outer surface, then this pipe should be scrapped; ➃ If the defect surface area of the cement mortar protective layer is more than 5% of the surface area of outer protective layer, the cement mortar protective layer should be re-made after removing it completely; ➄ If the pits or bubbles appear on the inner and outer surfaces of core pipe concrete, they should be filled and leveled with cement mortar or epoxy cement mortar when the width or depth is greater than 10mm. 5.6.13 Factory inspection 1. Inspection items: including pipe appearance quality, dimensional deviation, pipe cracks, internal pressure or external pressure anti-cracking performance, compressive strength of core pipe concrete and protective layer cement mortar, and water absorption rate of protective layer cement mortar. 2. Sampling inspection scheme: The batch of pipes to be inspected should be composed of finished pipes with the same category, specification, and process, and each 200 pieces shall be a batch. When the number of pipes is less than 200, it can also be used as a batch, but it should be at least 30. The sampling quantity is determined in accordance with Table 5.34. 3. Decision rules: A-type inspection items are in compliance with the inspection regulations, and less than two B-type inspection items out of tolerance can be judged as qualified. 5.6.14 Mark, transportation, storage, use, and delivery certificate of pipes 1. Marking content: company name, product trademark, production license number, product mark, production date and warnings such as “no collision”. 2. When lifting, take necessary measures to prevent pipe joints from being damaged.

58

5 Pipe for Pipe Jacking

Table 5.34 Number of samples for factory inspection Serial number

Quality index

Category

1

Appearance Quality

A

2 3

B

Inspection Item

Quantity

Socket working surface

Every one By batch

Spigot working surface

Every one

Pipe crack

Every one

Pipe outer wall

Every one

5

Pipe inner wall

Every one

6

Repair quality and omissions

Every one

Inner diameter of socket face (Bb )

10

8

Outer diameter of socket face (Bs )

10

9

Thickness of protective layer (tg )

2

Pipe inner diameter (D)

10

4

7

Dimensional Deviation

A

B

10

Remarks

11

Socket depth (C)

10

12

Spigot length (E)

10

13

Ovality of socket (%)

10

Random selection

14

Socket ovality (%)

10

15

End face inclination

10

Internal or external pressure anti-cracking

2

17

Compressive strength of core pipe concrete

Check production records

18

Compressive strength of protective layer cement mortar

19

Water absorption rate of protective layer cement mortar

16

Physical and mechanical

A

3. Finished pipes should be stacked separately according to different pipe types, nominal inner diameters, working pressures, and soil covering depths, and should not be mixed. 4. The allowable stacking layers of finished pipes are listed in Table 5.35. For pipes with a nominal diameter less than 1000 mm, the stacking layers can be appropriately increased if measures are taken. Table 5.35 Maximum stacking layer of pipe section Nominal diameter

400–500

600–900

1000–1200

≥ 1400

Stacked layer

4

3

2

1 or upright

5.6 Prestressed Steel Cylinder Concrete Pipe

59

5. When storing under dry climate conditions, later watering maintenance shall be carried out. 6. The Factory certificate shall include: Manufacturer name, production license number, abbreviated product pipe category, product specifications, steel standard strength, elongation, steel wire diameter, standard strength, number of twists, reinforcement area, rubber ring inspection certificate, etc.

Chapter 6

Engineering Environment and Geological Survey

6.1 Engineering Environmental Survey 6.1.1 General provisions 1. The object of engineering environment survey is the construction site environment, which refers to the things that have an impact on the construction of the project or the construction has an impact on it, including ground environment and underground environment. 2. The ground environment should include: natural geographical features, ground structures, overhead cables, etc.; the underground environment should include: underground structures, underground pipelines, underground obstacles, etc. 3. The type, distribution range, size, location, current status of use, etc. of underground obstacles related to the project should be ascertained. 4. The distribution positions of gases and other harmful substances harmful to the human body within the scope of pipe jacking should be checked. 5. In chemical zone, the extent and distribution range of underground industrial pollution should be ascertained. 6.1.2 Ground environmental survey 1. In accordance with the requirements of protecting surface buildings and underground pipelines, maintaining road traffic, ensuring project quality, safety, and civilized construction, detailed on-site investigations must be carried out. 2. For various immovable objects, facilities, and structures on the ground that may be affected by construction, the name, purpose, size, degree of stability, structural form, positional relationship, and use status should be marked. 3. For important buildings (structures), it is advisable to obtain the completion data of the structures, especially the foundation conditions of the buildings (structures). 4. For the facilities being used, it is better to contact the management unit to understand the usage. © China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_6

61

62

6 Engineering Environment and Geological Survey

6.1.3 Underground environment survey 1. For the various underground structures that may be affected by the construction, the position relationship and distance between the jacked pipeline and underground structures, as well as the name, purpose, size, structure form, buried year and current use status of underground structure should be indicated. 2. As far as possible, the completion data of underground structures shall be obtained, or excavate exploratory holes and trenches to obtain detailed information. 3. For abandoned underground pipelines and structures, the type, location, size, integrity, nature of the residual content and leakage should also be carefully investigated. 4. The status of ground and underground buildings (structures), various underground pipelines and obstacles along the pipe jacking line and within the scope of influence shall be ascertained, and the degree of impact on the pipe jacking project shall be evaluated, and if necessary, it can be notarized and archived by multiple parties.

6.2 Engineering Geological Survey 6.2.1 General provisions 1. The object of engineering geological survey is the rock, soil and groundwater within the scope of the engineering site and surrounding area. 2. The geomorphology, geology, stratum structure characteristics, soil properties and space distribution related to the project should be ascertained. 3. The flood inundation area, the erosion and stability of riverbed to be crossed should be ascertained. Evaluate the stability of the rock slope and put forward suggestions for slope protection. 4. The distribution range, occurrence state, embedment depth and characteristics of surface and underground buried rivers, lakes, ponds, ditches, caves, pits and wells along the pipe jacking line shall be ascertained, and the engineering geological characteristics of the overburden shall be provided. 5. The development of adverse geological processes and the possibility of geological disasters along the pipe jacking line should be ascertained, including karst, landslides, dangerous rocks and collapses, mudslides, goafs, ground subsidence, seismic effects of sites and foundations, active fault, etc. 6. The hydrogeological conditions along the line should be ascertained, and groundwater control plans should be proposed. 7. The exploration hole must be plugged to avoid slurry emission during pipe jacking process. 8. The survey is divided into two stages: preliminary survey and detailed survey.

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63

6.2.2 Geotechnical investigation 1. The overlying stratum, the soil layer and the lower soil layer of pipe jacking shall be investigated in detail; 2. The special rock and soil along the pipe jacking line shall be ascertained, including collapsible soil, red clay, soft soil layer, mixed soil layer, fill soil layer, permafrost layer, swelling soil layer, saline soil layer, weathered rock and residual soil layer, various contaminated soil layers, etc., and the degree of their impact on the pipe jacking should be evaluated; 3. The distribution range, burial depth, thickness and engineering geological characteristics of the soft soil layer along the pipe jacking line, which may produce submerged corrosion, quicksand, piping and seismic liquefaction, should be ascertained. 6.2.3 Groundwater survey 1. The types of groundwater, aquifers, groundwater burial conditions, recharge and discharge conditions, and distribution characteristics should be investigated; 2. The highest water level, lowest water level, and water level change range of groundwater in history should be investigated; 3. The change of groundwater temperature with depth should be measured. When there is no groundwater, the change of soil temperature with depth should be measured; 4. The corrosivity of groundwater to concrete, steel, cast iron and rubber should be tested; 5. The pH value of groundwater, the content of chloride ion, calcium ion and sulfate ion, etc., and the degree of corrosion of groundwater to concrete, steel, cast iron and rubber should be measured; 6. When there is confined water distributed underground, the pressure of confined water should be measured to evaluate its impact on pipe jacking. 6.2.4 Preliminary survey 1. Mainly focus on data collection and on-site investigation; 2. The soil samples taken in the preliminary survey and the in-situ test shall meet the following requirements: (1) The soil samples and exploration points for in-situ testing should be arranged according to the geological unit, stratum structure and the engineering properties of soil, the number can account for 1/4 to 1/2 of the total number of exploration points; (2) The number of soil samples taken and the vertical space of in-situ test in the hole should be determined according to ground characteristics and soil uniformity. Soil samples or in-situ tests should be taken for each layer of soil, and the number should not be less than 6.

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6 Engineering Environment and Geological Survey

6.2.5 Detailed survey 1. The geotechnical engineering conditions along the pipe jacking line should be ascertained, and the geotechnical characteristic parameters required for the design of the pipe jacking project should be proposed. 2. For the detailed survey, taking soil samples and conducting in-situ tests shall meet the following requirements; (1) The quantity of exploration for taking soil samples and conducting in-situ tests shall be determined according to the stratum structure, soil uniformity and design requirements, and each jacking section shall not be less than 2 pieces; (2) The undisturbed soil samples or in-situ test data of each main soil layer along the pipe jacking line shall not be less than 6 pieces (groups). 6.2.6 Exploration hole layout 1. General provisions (1) Preliminary survey: 1–2 exploration holes should be arranged for each pipe jacking section. The exploration hole space should be 50–100 m when long distance pipe jacking, and at least one exploration hole should be arranged at the position of pipe jacking pit. (2) Detailed survey: 2–3 exploration holes should be arranged for each pipe jacking section. The exploration hole space should be 30–50 m when long distance pipe jacking, and the position of the pipe jacking pit should be at least 1–2 exploration holes. 2. Location of exploration hole (1) The exploration holes should be arranged on both sides of pipeline design axis, within 10 m on land and 20 m on water, and should not be arranged above the jacking pipeline. (2) The exploration holes of the rectangular working pit should be arranged at the four corners, and the exploration holes of the round working pit should be evenly arranged along the periphery. (3) When the pipeline passes through buried rivers, ponds (lakes), trenches, wells, pits (holes) and other sections, the exploration holes should be appropriately dense. (4) When the pipeline traverses a section with development of unfavorable geological processes or a section with special rock and soil, the survey holes should be appropriately dense. (5) Where the pipeline crosses railways, highways, and river valleys, exploration holes should be arranged on both sides of river and road. (6) The exploration hole space is determined based on the principle of being able to control the soil quality changes in stratum. It should be 30–100 m and not be less than 2 exploration holes when crossing railways and highways or not be less than 3 exploration holes when crossing river valleys.

6.2 Engineering Geological Survey

65

3. Depth of exploration hole (1) The depth of exploration hole of pipe jacking should generally reach 3–5 m below the design elevation of pipeline bottom. (2) The depth of exploration hole of pipe jacking pit can be 5 m below the pit bottom, and it should be appropriately deepened under special circumstances. (3) When one of the following situations occurs, the depth of the exploration hole should be appropriately increased: (a) When the pipeline crosses a river valley, the depth of the exploration hole should reach 4–6 m below the maximum erosion depth of the riverbed; (b) When there is a soft soil layer or an incomplete fill at the base of the pipeline, the depth of the exploration hole should be increased appropriately; (c) When there are formations that may produce quicksand, submerging corrosion, piping or seismic liquefaction in the base of the pipeline, it shall be drilled through; (d) When lowering the groundwater level is adopted, the depth of the exploration hole should be drilled to 5–10 m below the bottom of foundation pit or pipeline; (e) When there is a confined aquifer under the cohesive soil layer that has been proved by the existing data or during the exploration process, and the water head is high and dewatering is required, the exploration hole should be appropriately deepened and the pressure of the confined water should be measured. 6.2.7 Geological survey report 1. General provisions (1) The geological survey report for pipe jacking project is composed of text and diagrams. (2) The construction survey report should meet the specific requirements of design and construction, provide corresponding information, and make analysis, conclusions and suggestions. (3) The survey reports at different stages should meet the technical requirements of project planning, design, and construction stages. (4) The preliminary survey report shall describe the site engineering geological conditions, evaluate its stability and adaptability, recommend the optimal route plan of pipeline, and provide the basis for rationally determining the layout, selecting jacking elevation, and preventing and controlling adverse geological phenomena. (5) The detailed survey report shall evaluate the geotechnical engineering conditions section by section. The physical and mechanical properties of each soil layer, as well as groundwater data required for the design and construction of pipe jacking and working pits shall be provided. Make suggestions and

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make targeted analysis and evaluation. The suggestions on the design and construction scheme of pipe jacking and working pit shall be put forward, and targeted analysis and evaluation shall be made. (6) For projects with simple engineering geological conditions and small survey engineering volume, the contents of the survey report can be appropriately simplified. 2. The content of survey report should include the following: (1) (2) (3) (4) (5)

(6) (7)

(8)

(9) (10) (11) (12)

The technical standards for survey; The purpose and tasks of survey; The basic characteristics of the proposed pipe jacking project; Survey method and survey work layout description; Description and evaluation of site topography, geology (stratum, geological structure), topography, rock and soil properties, groundwater and adverse geological phenomena; Analysis and selection of geotechnical parameters; Describe the adverse geological effects and special geotechnical soil that may affect the project stability, and evaluate the damage degree of pipe jacking project; Forecast of geotechnical problems that may occur during project construction and use, and give recommendations for monitoring and prevention measures; Suggested groundwater control measures; Recommended pipe jacking measures and working pit support measures; Design and construction suggestions for the foundation and back of the pipe jacking pit; Design and construction suggestions for pipe jacking projects.

3. The charts of survey report should include the following: (1) (2) (3) (4) (5) (6) (7) (8)

Layout plan of survey hole; Engineering geology histogram; Engineering geological cross section map; In-situ test results chart; Chart of indoor test results; Geotechnical engineering calculation diagram and calculation result chart; The diagram of the proposed pit foundation and back soil treatment plan; Diagrams of recommended groundwater control plan, working pit support plan and pipe jacking plan; (9) When necessary, special geotechnical distribution maps, comprehensive engineering geological maps, or engineering geological divisions (sections) maps, groundwater level maps, sketches and photos can be attached. 4. Basic requirements of geotechnical physical and mechanical indexes:

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67

(1) The physical and mechanical properties of rock and soil should be counted separately according to engineering geological zone (section) and layer position. When the index of the same layer of soil is quite different, the soil quality unit should be further divided and counted separately; (2) In survey report, the average value, maximum value, minimum value, sample number, mean square error and coefficient of variation of geotechnical parameters shall be provided; (3) The main soil parameters required for pipe jacking should be provided. The soil parameters must include: soil particle analysis, compactness, vertical and horizontal permeability coefficient, cohesion, internal friction angle, friction coefficient between soil and concrete, steel or glass fiber reinforced plastic and other materials, soil deformation modulus, Poisson’s ratio, bearing capacity of foundation, and other necessary conventional parameters, see Table 6.1. Table 6.1 Main soil parameters required for pipe jacking survey Category

Parameter

Inherent properties of soil

1. Particle composition and distribution

Symbol

Unit %

2. Non-uniformity coefficient

Cu

3. Plastic limit

ωP

%

4. Liquid limit

ωL

%

5. Liquid limit index

IL

6. Plastic limit index

IP

7. Mineral composition 8. The degree of rock weathering State characteristics of soil

Mechanical properties of soil

1. Water content

ω

%

2. Saturation

Sr

%

3. Void ratio

e

4. Permeability coefficient

K

m/d

5. Natural weight

γ

kN/m3

6. Dry weight

γd

kN/m3

1. Cohesion

c

kPa

2. Internal friction angle

ϕ

°

3. Standard penetration blow count

N

4. Unconfined compressive strength of undisturbed soil

qu

kPa

5. Compression modulus

Es

MPa

6. Compressive strength of pebbles or rocks

σC

MPa

7. Shear strength of pebbles or rocks

τ

kPa

8. Bearing capacity

fka

kPa

Chapter 7

Working Pit

7.1 General Provisions 7.1.1 The working pit for pipe jacking includes jacking pit and receiving pit. 7.1.2 The support structure, support strength, as well as the length, width and depth of working pit shall be considered. 7.1.3 Working pits for special purposes shall meet the requirements of urban planning and design. 7.1.4 After completing all the work, the backfilling of work pit must be carried out as soon as possible. 7.1.5 The working pit must be stable during production and use process.

7.2 Working Pit Design 7.2.1 The following factors should be considered in the site selection of working pit: 1. 2. 3. 4. 5. 6. 7. 8. 9.

The location of well chamber on pipeline; Convenience of drainage, excavation and transportation; The impact on surrounding buildings (structures) is minimal; Avoid ground and underground buildings (structures), obstacles, or locations where it is easy to protect the ground and underground buildings (structures); Close to power and water sources; Convenient transportation; Avoid residential areas, high-voltage lines and cultural relics protection areas; When pipeline slope is large, the jacking pit should be set at the deeper end of the pipeline; In pipe jacking with curve and straight line, the jacking pit should be set at the straight end.

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7.2.2 Plane shape of working pit: 1. On the plane, the working pits are rectangular, circular, elliptical, polygonal, etc. 2. When a straight pipe jacking or a broken line with two sections of intersection angle close to 180°, a rectangular working pit can be used. 3. When intersection angle of two sections is relatively small or at the same position pipeline needs to be jacked or received in multiple directions, circular or polygonal working pits can be used. 7.2.3 Supporting form of working pit: 1. Working pit support should be a closed structure, and the support forms include: caisson, diaphragm wall, cast-in-place pile, SMW (Soil Mixing Wall), steel sheet pile, etc.; 2. When the depth of working pit is shallow, the groundwater level is low, and the jacking distance is short, steel sheet pile or SMW should be used; 3. When the working pit is deep and the pipe jacking force is large in soft soil area, caisson or diaphragm wall should be adopted; 4. When the site is small and the surrounding buildings need to be protected, diaphragm wall should be preferred; 5. When the groundwater level is low or there is no groundwater area, cast-in-place piles can be used; 6. Internal supports should be provided in working pit, which should form a closed frame, and diagonal bracing should be provided at four corners of rectangular working pit; 7. When jacking force is large, a reinforced concrete back wall should be set in jacking pit. 7.2.4 Work pit size: The work pit size refers to the smallest clearance size that can satisfy pipe jacking construction. Taking the rectangular working pit as an example, the working pits of other shapes are determined with reference to the rectangular working pit size. 1. The clearance length of working pit (1) When the length of pipe jacking machine is greater than the length of pipe section, it can be calculated according to the following formula: L pi pejacking = L 1 + L 2 + L 3 + L 4 + L 5 + L 6 where: L pi pejacking L1 L2 L3 L4 L5

(7.1)

minimum clearance length of jacking pit (m); back wall thickness (m); the length of main jack cylinder (m); the operation space soil removing (m); the length of pipe jacking machine (m); the reserved distance between pipe jacking machine and waterstop wall (m);

7.2 Working Pit Design

71

L6

the thickness of water-stop wall or the installation length of water-stop ring (m). (2) When the length of pipe jacking machine is less than the length of pipe section, it can be calculated according to the following formula: L pi pejacking = L 1 + L 2 + L 3 + L 4 + L 5 + L 6

(7.2)

where: L pi pejacking L1 L2 L3 L4 L5

minimum clearance length of jacking pit (m); back wall thickness (m); the length of main jack cylinder (m); the operation space soil removing (m); the length of pipe section (m); the reserved distance between pipe jacking machine and waterstop wall (m); L6 the thickness of water-stop wall or the installation length of water-stop ring (m). 2. The clearance length of receiving pit Lr p = L4 + L7

(7.3)

where: L r p the minimum clearance length of receiving pit (m); L 4 the length of pipe jacking machine (m); L 7 the length of operation space of pipe jacking machine (m), usually 0.5 m in front and 0.5 m in rear of pipe jacking machine. 3. The clearance width of jacking pit B j p = B1 + B2 + B3

(7.4)

where: Bjp B1 B2 B3

minimum clearance width of jacking pit (m); the outer diameter of pipe jacking machine (m); the width of operation space on the left side of pipeline (m); the width of operation space on the right side of pipeline (m).

4. The clearance width of receiving pit Br p = B1 + B4 where: Br p the minimum clearance width of receiving pit (m); B1 the outer diameter of pipe jacking machine (m);

(7.5)

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7 Working Pit

B4

the reserved width (m) for operation space of pipe jacking machine exiting the pit, usually 0.5 m on the left and right sides of pipe jacking machine, totaling 1.0 m.

5. The clearance depth of jacking pit (see Fig. 7.1) It is considered that the top surface of guide rail in foundation pit is the same as the design elevation of pipe invert, the depth is determined by the following formula: H1 = (U − V ) + h 1 + h 2

(7.6)

where: H1 U V h1 h2

the depth of jacking pit (m); current ground elevation (m); the design elevation of pipe invert (m); the height of guide rail in foundation pit (m); the pad height under guide rail in foundation pit (m).

6. Determining the clearance depth of the receiving pit: H2 = (U − V ) + T + h 3

(7.7)

where: H2 the depth of receiving pit (m); T wall thickness of pipe (m); h 3 reserved height of water stop ring in receiving pit (m), generally not less than 250 mm.

7.3 Acceptance of Working Pit 7.3.1 The acceptance of working pit shall be carried out in accordance with the requirements of Table 7.1. 7.3.2 Support strength 1. The surrounding surface structure is stable, and there is no deformation, cracks, or collapse on the ground. 2. The bottom can bear the weight of jacking pipe and pipe jacking machine without deformation and cracks. 3. There is no deformation, cracks, or collapse on the side wall. 4. The supporting structure is stable, solid and safe. 5. The back wall can withstand the maximum thrust during pipe jacking.

7.3 Acceptance of Working Pit

73

Fig. 7.1 Depth of jacking pit

Table 7.1 Inspection items and requirements of working pit for pipe jacking Serial number

Item

Requirement

Inspection frequency Scope

Frequency

1

Support stability

Stable

Side wall

4 places

Observation and evaluation

2

Bottom bearing capacity

Enough

Pit bottom

4 places

Observation and evaluation

3

Compressive strength of back wall

Meet the design Back wall requirements

2 places

Observation and evaluation

4

Surrounding surface

No deformation or cracks

2 places/side

Observation and evaluation

Surrounding

Testing method

7.3.3 Over-excavation 1. When the working pit is excavated, the base soil layer should not be disturbed. When the base is over-excavated, backfilling of empty soil is strictly prohibited. 2. During excavation of working pit, the soil around the side wall should not be disturbed. When over-excavation occurs, it should be backfilled tightly.

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Table 7.2 Allowable deviation and inspection method of working pit for pipe jacking Serial number

Item

Allowable deviation

Check frequency

Testing method

1

Working pit length

40 mm

Twice per side wall

Steel ruler

2

Working pit width

40 mm

Twice per side wall

Steel ruler

3

Verticality of side wall

< H/300

Twice per side wall

Steel ruler, hanging line

Note H in the table is the depth of working pit

3. The back soil of jacking pit should not be disturbed or over-excavated. The back soil and back wall should be close and dense, and when there is a void, it should be filled tightly. 7.3.4 Allowable deviation: The deviation of working pit shall meet the requirements of Table 7.2.

Chapter 8

Pipe Jacking Equipment and Instruments

8.1 Unit Division of Pipe Jacking Equipment 8.1.1 Jacking pit unit: including jacking pit, receiving pit, water stop ring, back iron, guide rail in foundation pit. 8.1.2 Excavating unit: including various types of pipe jacking machines. 8.1.3 Jacking unit: There are two parts: main jacking station and intermediate jacking station. The main jacking equipment includes main jacking cylinder, main pump station, cylinder support, oil pipe, equalizing jacking iron, and jacking iron; the intermediate jacking equipment includes pipe for intermediate jacking station, pump station, cylinders, etc. 8.1.4 Measuring unit: including total station, theodolite, level, pointer, inclinometer and other guiding equipment. 8.1.5 Grouting unit: including mixer, storage tank, grouting pump, grouting pipe, pressure gauge, etc. 8.1.6 Soil conveying unit: including soil conveying car, car track, water inlet pipe, mud pipe, slurry pump, sedimentation tanks, mud-water separators, mud-water mixers, etc. 8.1.7 Vertical transportation unit: including various types of hoisting machinery, such as tripod, gantry frame, crane, etc. 8.1.8 Lighting unit: including low-voltage transformer, wire, lighting lamps, etc. 8.1.9 Ventilation unit: including exhaust fan, blower, ventilation pipe, etc. 8.1.10 Power supply unit: including transformer, generator, cable, switch box, etc.

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8 Pipe Jacking Equipment and Instruments

8.2 Pipe Jacking Instrument 8.2.1 Gas detector should be installed in pipe jacking machine or pipeline to detect the content of oxygen and harmful gas in pipeline. 8.2.2 Pressure gauges should be installed in the soil chamber (or slurry chamber) of balanced pipe jacking machine to detect the soil or slurry pressure in chamber. Refer to Table 8.1, the pressure gauges should be evenly arranged in the soil chamber (slurry chamber). 8.2.3 Inclinometer should be installed in pipe jacking machine to detect the degree of inclination and rotation of pipe jacking machine. 8.2.4 Stroke meter should be installed on each group of correction cylinders to detect the extension length of correction cylinders to determine the correction direction and correction angle. 8.2.5 Flow meter should be installed on slurry inlet and discharge pipelines for slurry pipe jacking machine to detect the difference in flow rate of slurry inlet and discharge to determine the volume of discharged soil. 8.2.6 Pressure gauge should be installed on friction reduction slurry conveying pipeline to measure the conveying pressure of friction reduction slurry. 8.2.7 During jacking process, it is advisable to install gauge of friction reduction slurry pressure in grouting hole of pipeline to detect the fullness of friction reduction slurry. 8.2.8 During treatment after jacking, pressure gauge should be installed at the exit of grouting pipeline for consolidation slurry, which can detect the injection pressure of consolidation slurry and the fullness of consolidation slurry. 8.2.9 Stroke meter can be installed on main jacking cylinder and intermediate jacking cylinder to detect the extension length of cylinder. 8.2.10 During jacking process, guiding instrument must be used to accurately determine the direction of pipe jacking. 8.2.11 During jacking process, measuring instruments must be used to detect the center line deviation and vertical deviation of pipeline. Table 8.1 Reference number of pressure gauges in soil (slurry) chamber Pipe diameter (mm)

< 1000

1000–1400

1400–2000

2000–2600

2600–3000

> 3000

Number of pressure gauges

1

2

3

4

5

6

8.3 Equipment Installation

77

Fig. 8.1 Schematic diagram of pipe jacking equipment installation

8.3 Equipment Installation 8.3.1 The pipe jacking equipment installed in jacking pit includes the supporting panel, guide rail, the sealing rubber ring, the main jacking cylinder, pipe jacking machine, jacking iron, etc., as shown in Fig. 8.1. 8.3.2 Supporting panel 1. Supporting panel should be set between main jacking cylinder and back supporting wall. The supporting panel, back supporting wall and back soil shall jointly bear the reaction force of pipe jacking. The panel has two forms of integrated type, and assembly type which is shown in Fig. 8.3. 2. The supporting panel area should be such that the bearing capacity of the soil behind back supporting wall meets the maximum jacking force requirement. The panel should have sufficient strength to withstand the maximum reaction force of main jacking cylinder without damage. It should also have sufficient rigidity and should not be deformed during jacking process. 3. The panel material should be uniform, and its surface should be straight and should be perpendicular to the axis of pipeline in both vertical and horizontal directions. 4. The panel structure should be simple and easy to assemble and disassemble. 5. During pipe jacking, the panel should be checked at any time. If severely inclined or deformed, it must be reinstalled. 6. The allowable deviation of the panel should meet the requirements in Table 8.2. 7. The supporting panel positioning can use hanging line method (see Fig. 8.2): (1) According to the jacking center line, determine O and P points on the jacking pit ground and M and N points on jacking pit sidewall;

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8 Pipe Jacking Equipment and Instruments

(2) Hang a line between M and N points and a vertical line on it; (3) On the plane and on ground of jacking pit, determine two points R and S, the line RS is perpendicular to the jacking center line, hang vertical lines at R and S points and measure the distance a, b between two ends of RS line and back. The distance between these two measuring points is c, then (a − b)/c is horizontal torsion of the panel; (4) In vertical direction, measure the distances d and e from the top and bottom of the panel to vertical line. The distance between these two measuring points is l, then (d − e)/l is verticality torsion of the panel; (5) Verticality and horizontal torsion of the panel should meet relevant requirements. 8. During continuous jacking, the pipe that has been jacked can be used as back support. the requirements are as follows: (1) Main jacking supporting panel must be installed at the front end of pipe jacked, and cushioning materials should be embedded between the panel and pipe jacked; (2) The maximum jacking force of pipes to be jacked should be less than the jacking force of pipes jacked, otherwise the pipe jacked must be reinforced; (3) Measures should be taken to protect the joints of pipes jacked from damage. 9. Estimation of supporting panel stability: (1) The panel must be able to withstand the reaction force of maximum total jacking force F. (2) Assuming that the thrust of main jacking cylinder is transmitted through the back supporting wall and acts evenly on the back soil, when the following formula is established, the supporting panel is considered to be stable (Fig. 8.2): ( F 60

1.2–51.5

55–70

70–85

0.8–1.0

0.30–0.35

Medium hard rock

30–60

1.50–2.00

45–60

60–75

0.8–1.0

0.20–0.30

Soft rock

≤ 30

2.00–2.50

30–50

40–60

0.5–0.8

0.07–0.15

Remark 1. The relative distance of soft rock smooth blasting should be a small value 2. The concentration of charge is considered based on No. 2 rock ammonium nitrate explosive. When other explosives are used, conversion should be carried out. The conversion indicators are mainly fierceness and explosive force (average value)

Table 9.4 Charge coefficient value α Blasthole name

Rock category II, III

IV

V

VI

Cut hole

0.5

0.55

0.60

0.65–0.80

Auxiliary hole

0.4

0.45

0.50

0.55–0.70

Peripheral hole

0.4

0.45

0.55

0.60–0.75

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9 Jacking Construction

Table 9.5 Weight per meter of No. 2 rock ammonium ladder explosive γ Charge roll diameter (mm)

32

35

38

40

44

45

50

γ (kg/m)

0.78

0.96

1.10

1.25

1.52

1.59

1.90

Table 9.6 Reference value of smooth blasting parameters Rock category

Blasthole space E (cm)

Resistance line W (cm)

Density factor K = Charge E/W concentration (kg/m)

Hard rock

55–70

60–80

0.7–1.0

0.30–0.35

Medium hard rock

45–65

60–80

0.7–1.0

0.20–0.30

Soft rock

35–50

40–60

0.5–0.8

0.07–0.12

Table 9.7 Allowed over-excavation (cm) Excavation site

Surrounding rock condition category Hard rock VI

Medium hard rock and soft rock V–III

Broken loose rock and soil II–I

Top

Average 10 Max 20

Average 15 Max 25

Average 10 Max 15

Sidewall and bottom

Average 10

Average 10

Average 10

Note Ultimate compressive strength of hard rock Rb > 60 MPa, medium hard rock Rb = 30–60 MPa, soft rock Rb < 30 MPa

9.5 Water Flushing Pipe Jacking 9.5.1 The following conditions apply to water flushing pipe jacking: 1. Suitable for soft plastic, flow plastic clay or soft plastic, flow plastic cohesive soil with thin layer of silt sand. When the requirements for surface settlement are not strict, it can also be used in loose non-cohesive sand; 2. Allow large deformation of soil and ground around pipeline; 3. There should be groundwater in stratum; 4. The pipe diameter should be between 1000 and 2400 mm; 5. The covering soil above pipe should be more than 2 times pipe diameter and should not be less than 4 m thick. 9.5.2 Main construction equipment: water flushing pipe jacking machine, high pressure water pump, mud pump, main jacking cylinder, main jacking oil pump, high pressure water pipe, slurry pipe, etc. 9.5.3 Operation procedure of water flushing method: 1. Turn on the high-pressure water pump and water inlet valve to establish the corresponding working water pressure;

9.6 Compaction Pipe Jacking

103

2. Determine flushing position according to deviation correction requirements, and turn on the water gun flushing operation in corresponding position; 3. When slurry pressure in slurry chamber reaches the requirement, start the slurry pump to discharge slurry; 4. Adjust the amount of water inflow and the amount of mud discharged to balance the two and maintain the pressure of slurry chamber; 5. Start the main jacking oil pump and the main jacking oil cylinder; 6. When jacking, friction reduction mud must be injected into the annular space between pipe and soil layer, and grouting amount of should be determined according to factors such as jacking speed, pipe diameter and soil quality; 7. During jacking, deviation of pipe jacking machine should be continuously measured, and the flushing direction of water gun should be adjusted in time; 8. When stopping jacking, the main jacking oil pump should be turned off first, then the high-pressure water pump and mud pump should be turned off synchronously; 9. To ensure the stability of excavation surface, the front end of pipe jacking machine should always be cut into the soil. 9.5.4 Handling of common problems 1. In cohesive soil, high pressure water can be used to break the squeezed soil block only after the front end of pipe jacking machine is completely cut into soil; 2. In silt soil, in order to reduce the face resistance in jacking, part of the soil at front end of pipe jacking machine can be crushed first, but the crushing range should be controlled to prevent the face soil from collapsing; 3. The high-pressure water pump should be arranged near jacking pit; 4. Ensure that water inlet pipe is straight, reliable, non-seepage and non-leakage; 5. The inlet water should be clean water that does not contain sediment and other impurities; 6. In silt soil, the inlet pressure should be 0.4–0.6 MPa, and in cohesive soil, the inlet pressure should be 0.7–0.9 MPa; 7. In mud discharged, the ratio of muck to water should be controlled at about 1:8.

9.6 Compaction Pipe Jacking 9.6.1 The following conditions apply to compaction pipe jacking: Applicable soil quality: silty soil, moderate water content in soil; Applicable pipe diameter: medium and small diameter; Applicable distance: medium and short distance; Settlement requirements: low requirements for ground settlement or allow uplift and settlement to occur; 5. It should be used with caution in site where gas and water pipelines or other structures that are buried within 5 m from left and right sides of the center line in pipe jacking and are easily damaged by compaction. 1. 2. 3. 4.

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Fig. 9.4 Compaction pipe jacking machine

9.6.2 The large end of bell mouth of pipe jacking machine is entry window, and the small end is unearthed window. The entry window is usually equal to the outer diameter of pipe jacking machine head, as shown in Fig. 9.4. The area ratio of front end of pipe jacking machine to unearthed window is the opening rate of extrusion pipe jacking machine: α=

d2 D2

(9.6)

where, α opening ratio; D outer diameter of pipe jacking machine head; d inner diameter of unearthed window. 9.6.3 Main construction equipment: compaction pipe jacking machine, slag conveying equipment (conveyor belt, trolley or rail-type car), main jacking oil cylinder, main jacking pump station, wire rope saw and other cutting tools. 9.6.4 Construction process of compaction pipe jacking: as shown in Fig. 9.5. 9.6.5 Construction methods and technical parameters 1. Before construction, the water content of crossing soil and the plasticity of silt must be analyzed and evaluated; 2. Determine the opening ratio of compaction pipe jacking based on the fluid plasticity of soil; 3. The resistance of soil squeezing into pipe jacking machine head is inversely proportional to the opening rate; 4. The cross-sectional area of unearthed window should be adjustable. When the local soil layer is soft, the area of unearthed window should be reduced, that is, the opening ratio should be reduced;

9.6 Compaction Pipe Jacking Fig. 9.5 Compaction pipe jacking process

105

Start jacking

Jacking direction Checking Stability of soil

Jacking

Breaking ground Connect the pipe

The main jacking impel Add the jacking iron Transport the soil Put down the pipe Align the pipe end face

The Pipe jacking machine enters the reception pit

5. Before pipe jacking, the vertical center of pipe jacking machine should be kept correct, the left and right sides must be symmetrical; 6. The opening ratio should be adjusted at any time according to the changes in soil layer; 7. The length of a single jacking should be determined according to the volume of earth truck, the lifting capacity and the ground transportation conditions; 8. Manual excavation should be used when pipe jacked enters and exist the hole, and the jacking speed should be slowed down; 9. When jacking, pipe jacking machine should be prevented from rotating. After it rotates, it should be corrected in time; 10. When jacking is temporarily stopped, the bell mouth should be fully cut into soil; 11. Jack in pipe jacking machine can be used for deviation correction. 9.6.6 Safety requirements

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1. When personnel are working in pipe, the toxic gas produced by the corrosive material in soft soil will endanger the life and safety of construction personnel, and ventilation in pipe must be strengthened; 2. When the thrust is too large and jacking speed is too fast, the pipe jacking machine squeezes the surrounding soil, which is prone to ground uplift, cracking and other phenomena; 3. When soil is too soft, the face soil may flow into the bell mouth naturally, and ground settlement is prone to occur. 9.6.7 Handling of common problems 1. The overburden layer should be thick enough, and the passive earth pressure of soil at front end of pipe jacking machine should be greater than the resistance of soil squeezing into the bell mouth, otherwise the ground is easy to uplift; 2. The unearthed window of pipe jacking machine should have a certain resistance so that the soil in front of pipe jacking machine will not automatically flow into the bell mouth, otherwise, the ground is prone to settlement; 3. When ground rises along pipe axis, jacking speed must be reduced and the area of unearthed window must be increased; 4. When the ground sinks along pipe axis, jacking speed must be increased and the area of unearthed window must be reduced.

9.7 Mechanical Excavation Pipe Jacking 9.7.1 The following conditions apply to mechanical excavation pipe jacking: 1. Applicable soil quality: soil layers with good stability and rock, do not contain water or have less water content; 2. Applicable pipe diameter: medium, large and huge diameter pipe jacking; 3. Applicable distance: middle and short distance pipe jacking; 4. Settlement requirements: allow the ground to uplift and settle. 9.7.2 Main construction equipment: pipe jacking machine, excavators, slag transportation equipment, main jacking cylinders, main jacking pump stations, tools, etc. 9.7.3 Construction process: as shown in Fig. 9.6. 9.7.4 Construction technical measures: the facing grid can be disassembled on site. When the stratum is unstable, install the grid to assist in stabilizing soil; when the stratum is stable, remove the grid so that the excavating tools are not blocked and improve excavation efficiency.

9.8 Pilot Boring Pipe Jacking Fig. 9.6 Mechanical excavation pipe jacking process

107

Start to jack

Jacking direction Check Stability of the soil excavate

Dump the waste soil The main jacking impel

Jacking

Pipe connection

Replace the jack iron set Put down the pipe Align the pipe end face

The pipe jacking machine enters the reception pit

9.8 Pilot Boring Pipe Jacking Pilot boring pipe jacking is a kind of pipe jacking that using drilling rigs for guiding, using screw machinery to discharge soil, and using jack to jack pipes. It is suitable for micro-diameter pipe jacking that cannot be accessed by personnel, and its single section jacking distance is short. 9.8.1 Construction principle The pipeline is laid in three steps. In the first step, a pilot drilling bit and guiding rods are used for drilling directionally; in the second step, expand small pilot hole along guiding rod and jack into protective pipe; and in the third step, jack product pipes to replace protective pipes. There are many types of pilot boring pipe jacking methods with some difference in technology. According to guiding method, there are laser guiding, wireline guiding, wireless guiding, manual guiding, etc.; according to slag discharge method, there are compacting, spiral, etc.; according to slag discharge direction, there are two types: front unearthed and back unearthed.

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9.8.2 Applicable conditions (1) Applicable soil quality: for soil layers with N value not greater than 50 in the standard penetration test, or soil layers with gravel size less than 30 mm and a content greater than 10%, or soil layers without gravel content greater than 30%. (2) Applicable pipe diameter: micro-diameter; (3) Applicable distance: short distance; (4) Settlement requirements: strict requirements for the ground uplifts and settlement; (5) The covering depth should be greater than 2 times the pipe outer diameter and not less than 1 m. When crossing rivers and lakes, the depth should not be less than 2.5 m; 9.8.3 Main construction equipment The main equipment should include: cranes, hydraulic power stations, main jacking platforms, guiding bits, guiding rods, spiral dump rods, steel casings, reamers, guiding instruments, etc. (Fig. 9.7). 9.8.4 Construction process 9.8.5 Construction technical measures 1. Pilot boring (1) In the process of pilot boring, small range and multiple correction measures should be taken, and correction records should be made. (2) When pilot boring, high-pressure drilling fluid should be used to assist the operation. (3) After the guiding rod is penetrated, the soil quality and obstacles should be analyzed to determine the hole expansion and jacking measures. 2. Dumping (1) When jacking small diameter pipes or soil layer has good compressibility, compression construction without soil discharge can be used. (2) When using front unearthed method, the rear end of guiding rod should be connected to dumping pipe, after which a reamer should be connected. (3) When using back unearthed method, the rear end of guiding rod should be connected to a reamer, after which dumping pipe should be connected. (4) When the soil is not smoothly discharged, the soil should be improved according to its characteristics. 3. Pipe jacking (1) The type of pilot boring machine should be selected reasonably according to soil quality. (2) The installation of jacking supporting panel and jacking equipment should refer to the relevant provisions of this standard. (3) When connecting the reamer, check whether the jetting hole is unblocked.

9.8 Pilot Boring Pipe Jacking

109

Preparation for construction

measurement and location

Drilling directionally

Steering

Dump the waste soil Expanding the pilot hole Install the protective pipe Receive the guide rod Jacking the pipe Replacing the pipe

Receive the protective pipe Uninstall the equipment

finished Check and acceptance Fig. 9.7 Pilot boring pipe jacking construction process

(4) Safety protection measures should be adopted when hoisting and connecting pipe sections. (5) When connecting pipe joints, seal rings and gaskets should be installed to prevent water leakage at pipe joints. (6) Jacking speed control should match the rotation speed of dumping machine and should refer to the ground deformation monitoring results.

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(7) During protective pipe and product pipe jacking, effective friction reduction measures should be taken according to the change of jacking force.

9.9 Pipe Jacking with Earth Pressure Balance 9.9.1 The following conditions are mainly applicable to earth pressure balance pipe jacking: 1. Applicable soil quality: clay, silt, sand, gravel with pebbles content < 20% and particle size < 100 mm, soil layer with or without water; 2. Applicable pipe diameter: medium, large and huge diameter; 3. Applicable distance: medium, long and ultra-long distance; 4. Settlement requirements: strict requirements for ground settlement; 5. Overburden soil: greater than 1.2 times pipe outer diameter, and not less than 2 m. 9.9.2 Main construction equipment: earth pressure balance pipe jacking machine, muck conveying equipment (conveyor belt, trolley or rail-type car), main jacking cylinder, main jacking pumping station, thrust ring, “U” jacking iron, etc. 9.9.3 Construction process: as shown in Fig. 9.8. 9.9.4 The construction technical measures are as follows: 1. Before pipe jacking, soil chamber pressure control value should be determined according to factors such as overburden soil thickness, soil properties and groundwater level; 2. During pipe jacking, adjust dumping speed and jacking speed according to the change of soil chamber pressure, so that the soil chamber pressure is always kept within the preset range; 3. Different soil improvement methods should be adopted according to different soil qualities; 4. When starting jacking, the cutter head shall be started to rotate first, and then the oil cylinder shall be started to advance; when stopping jacking, the oil cylinder should be stopped to advance first, and then stop the rotation of cutter head; 5. During pipe jacking, the friction reduction mud must be injected into pipe outer wall simultaneously, and grouting shall be appropriately supplemented according to the mud loss; 6. After penetration, soil consolidation slurry should be injected into pipe outer wall to replace the friction reduction mud; 7. During jacking process, the position of pipe jacking machine should be measured and positioned at any time, and the deviation should be corrected in time; 8. When it is close to underground pipelines, underground and above-ground structures, the pressure of soil chamber shall be appropriately reduced;

9.9 Pipe Jacking with Earth Pressure Balance

111

Preparation for construction

Measurement and location Guide rail Installation the equipment

Steel back

sealing rubber ring Put the shield machine into the launch shaft

Soil pressure adjustment

The main jacking impel Put down the pipe and align their interface Pipe jacking Mud for reducing the drag Orientation and correction the deviation

Discharge the soil

Soil improvement Shield machine goes into the receive shaft

Deal with the matter after jacking

Measure the whole pipe

Acceptance and check

Fig. 9.8 Pipe jacking process with earth pressure balance

Uninstall the equipment Deal with the pipe gap Mud displacement

Storage the soil on the ground

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9. When surrounding environment has strict requirements on soil deformation, soil deformation monitoring should be carried out, and jacking parameters should be adjusted at any time according to the monitoring data; 10. During initial jacking, pipe jacking machine should be prevented from rotating, and should be corrected in time after rotation; 11. When jacking in soft soil, dumping gate should be closed at any time to prevent soil from spurting out, resulting in a decrease in soil chamber pressure.

9.10 Slurry Balance Pipe Jacking 9.10.1 The following conditions are mainly applicable to slurry balance pipe jacking: 1. Applicable soil quality: silty soil, silt soil, sandy soil, sand and gravel with a gravel content of < 20% and a particle size of < 50 mm, and soil layers with or without water; 2. Applicable pipe diameters: small, medium, large and huge diameters; 3. Applicable distance: medium, long and ultra-long distance; 4. Settlement requirements: small ground settlement; 5. Overburden soil: greater than 1.5 times pipe outer diameter, and greater than 3 m. 9.10.2 Main construction equipment: slurry balance pipe jacking machine, water inlet pipe, mud discharge pipe, water inlet pump, mud pump, main jacking cylinder, main jacking pump station, thrust ring, “n” jacking iron, slurry separator, etc. 9.10.3 Pipe jacking process: as shown in Fig. 9.9. 9.10.4 The construction technical measures are as follows: 1. Before jacking, the control value of slurry chamber pressure should be determined according to factors such as overburden soil thickness at different positions, soil properties, and groundwater level; 2. During pipe jacking, adjust water inlet speed, mud discharge speed and jacking speed according to the change of slurry chamber pressure, so that slurry chamber pressure is always kept within the preset range; 3. When starting jacking, start inlet and outlet mud pumps firstly for internal and external circulation, then start cutter head, and finally start oil cylinder; when stopping jacking, stop oil cylinder jacking firstly, then perform external circulation, stop cutter head and turn to internal circulation, and finally, close the inlet and outlet mud pumps; 4. When using panel cutter head, the number and area of cutter head opening should be determined according to soil conditions; 5. When operating the water inlet valve, mud outlet valve, and bypass valve in pipe jacking machine, all valves cannot be in “closed” state at the same

9.10 Slurry Balance Pipe Jacking

113

Preparation for construction

Measurement and location Guide rail Installation the equipment

Steel back

Put the shield machine into the launch shaft

sealing rubber ring

adjust mud warehouse pressure

The main jacking impel Put down the pipe and align their interface Pipe jacking Mud for reducing the drag

Pump into the mud Discharge the mud

Orientation and correction the deviation

Soil improvement Shield machine goes into the receive shaft

Deal with the matter after jacking

Measure the whole pipe

Acceptance and check

Fig. 9.9 Slurry balance pipe jacking process

Uninstall the equipment Deal with the pipe gap Mud displacement

Deal with the mud

114

6.

7. 8.

9. 10.

11.

9 Jacking Construction

time; when switching from internal circulation to external circulation, straightthrough valves for water inlet and mud outlet should be opened first, and then close conversion valve; when switching from external circulation to internal circulation, conversion valve should be opened first, and then close water inlet valve and mud outlet valve; During pipe jacking, friction reduction mud must be injected into pipe outer wall simultaneously, and grouting shall be supplemented appropriately according to mud loss; After penetration, soil consolidation slurry should be injected into pipe outer wall to replace friction reduction mud; During jacking process, the position of pipe jacking machine should be measured and positioned at any time, and if deviation is large, it should be corrected in time; When it is close to underground pipelines, underground and above-ground structures, slurry chamber pressure should be appropriately reduced; When surrounding environment has strict requirements on soil deformation, deformation monitoring should be carried out, and jacking parameters should be adjusted at any time according to monitoring data; During initial jacking, pipe jacking machine should be prevented from rotating, and it should be corrected in time after rotation.

9.11 Air Pressure Balance Pipe Jacking 9.11.1 The following conditions apply to air pressure balance pipe jacking: 1. Applicable soil quality: clay, silt, sand, pebbles, gravel, and soil with large obstacles (such as stones, concrete, etc.); soil that is not suitable for dewatering or may cause serious settlement after dewatering; stratum permeability coefficient k should not be greater than 10–4 m/s; 2. Applicable pipe diameter: small, medium, large and huge diameter; 3. Applicable distance: only long distance pipe jacking has better economic efficiency due to the large investment; 4. Settlement requirements: small ground settlement; 5. Overburden soil: more than 2 times pipe outer diameter and greater than 4m, overburden soil must not cause gas leakage; 6. Environment: pipe jacking in underwater soil. 9.11.2 Main construction equipment: including air pressure balance pipe jacking machine, air pressure pump, air pressure tank, air pressure pipe, water inlet pipe, mud outlet pipe, water inlet pump, mud outlet pump, main jacking cylinder, main jacking pump station, thrust ring, “n” jacking iron, slurry separator, etc. 9.11.3 The pipe jacking construction procedure is as follows: 1. air pressure balance pipe jacking machine is divided into two cabins; the first cabin is excavation cabin, and the second cabin is transition cabin;

9.11 Air Pressure Balance Pipe Jacking

115

2. Before excavation, close the door of excavation cabin and pressurize the excavation cabin; 3. Construction personnel enter transition cabin, close the door of transition cabin and pressurize the transition cabin; 4. Open the door of excavation cabin, and transition cabin and excavation cabin maintain the same working pressure; 5. Construction personnel enter excavation cabin for construction and transport muck to transition cabin; 6. When excavating soil, close the door of excavation cabin, maintain the pressure of excavation cabin, then open the door of transition cabin, and transport muck out. 9.11.4 The construction technical measures are as follows: 1. Air pressure balance pipe jacking is divided into two types: full pressurization and local pressurization. Full pressurization pipe jacking means that the entire construction pipeline is filled with air at a certain pressure, and all construction personnel work under high pressure conditions; local pressurization pipe jacking only fills the excavation surface with air at a certain pressure, and only excavation personnel work under high pressure conditions; 2. There are two excavation methods, mechanical and manual. Mechanical excavation is the use mechanical means to break the soil, and the staff do not need to work at high pressure air environment; manual excavation is to manually break the soil, and only excavators need to work at high-pressure air; 3. During air pressure balance pipe jacking, air pressure acting on the working face should be greater than groundwater pressure 1 × 104 Pa to prevent the influx of groundwater into excavation cabin and dehydrate working face soil to improve its stability; 4. During pipe jacking, a suitable air pressure adjusting device should be selected according to the required air pressure; 5. The consumption of air can be determined by empirical formula: Q = α Dg2

(9.7)

where, Q required compressed air amount under normal pressure (m3 /min); Dg outer diameter of pipe jacking machine (m); a empirical coefficient, see Table 9.8. 6. Compressed air consumption can also be determined according to construction experience under the same formation conditions; 7. The maximum working pressure cannot exceed 3.6 × 105 Pa; 8. The construction personnel working in high air pressure is more dangerous, and corresponding safety protection measures should be taken.

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Table 9.8 Empirical coefficients of air consumption in different formations Stratum type

Homogeneous layer

Coarse sand layer

Middle sand

Fine sand

Silt layer

α

0.5–4.0

3.0–4.0

2.0–3.0

1.5–2.0

0.5–1.0

9.11.5 Common problems and solutions. 1. During air pressure balance pipe jacking, air avalanche is prone to occur, and air avalanche is usually divided into sudden air avalanche and corrosive air avalanche. 2. Sudden air avalanche is the formation of air pressure zone in soil. When the ground structure changes or the thickness of overburden is small, the highpressure air breaks through upper dense overburden soil and is released explosively. The pressure balance of excavation cabin may be disrupted. It will cause working face to collapse and endanger the safety of construction personnel. 3. Pressure relief holes can be set to prevent sudden gas avalanches, and the pressure relief holes should meet the following requirements: (1) Pressure relief hole should be drilled through upper clay layer; (2) The permeability coefficient of the filling in pressure relief hole should be greater than the value in upper clay layer, and also greater than that in lower soil layer; (3) In order to prevent other particles that affect permeability from entering the pressure relief hole, the borehole casing can be retained in soil layer, or other materials can be used to separate the filling from soil layer. 4. Measures to prevent corrosive air avalanche: (1) When designing for pipe jacking, full consideration should be given to the thickness of overburden soil; (2) Before construction, pay close attention to the air passages in the formation, including natural erosion ditches, rock cracks, artificial exploration holes, water wells, pressure relief holes, etc.; (3) When necessary, compaction grouting or other reinforcement methods can be used in overburden soil. 5. In order to reduce the working pressure of compressed air or reduce air leakage, the following measures can be adopted: (1) Lower groundwater level to reduce working pressure of compressed gas; (2) Lower groundwater level to reduce groundwater pressure, and maintain working face stability; (3) Use grouting method or freezing method to seal soil layer to prevent air leakage; (4) In complex stratum, it is advisable to adopt whole-process grouting to compact soil.

Chapter 10

Special Pipe Jacking

10.1 Micro-diameter Pipe Jacking 10.1.1 Slurry balance method or pilot boring method should be used for pipe jacking construction. 10.1.2 It is strictly forbidden for construction personnel to enter micro-diameter pipeline. 10.1.3 The total jacking force shall be controlled according to pipe allowable jacking force. 10.1.4 Jacking distance should be less than 100 m, and the longest should not exceed 150 m. 10.1.5 Length of a single pipe section should not exceed 2.0 m.

10.2 Extra-Long Distance Pipe Jacking 10.2.1 Intermediate jacking station for extra-long distance pipe jacking should meet the following requirements: 1. The effective stroke should not be less than 300 mm; 2. The capacity of hydraulic oil tank should be 3 times the full cavity capacity of jack. 10.2.2 Power supply facilities for extra-long distance pipe jacking shall meet the following requirements: 1. Power supply with sufficient capacity should be configured; 2. When the voltage drops to a level that cannot meet the normal construction needs, voltage regulation measures should be adopted. © China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_10

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10.2.3 Measurement in extra-long distance pipe jacking shall meet the following requirements: 1. Attitude indicator should be installed in pipe jacking machine; 2. The transfer station should be set up in pipe; 3. It is advisable to use an automatic measuring and positioning device for positioning and guidance. 10.2.4 Muck transportation shall meet the following requirements: 1. Pipeline transportation should be adopted for muck transportation; 2. Relay pumps should be installed in muck conveying pipeline. 10.2.5 The use of friction reduction mud should meet the following requirements: 1. It is advisable to use friction reducing mud with a small friction coefficient; 2. In main grouting pipeline, a pressurizing pump for friction reduction mud should be used; 3. The diameter of main grouting pipeline should be increased.

10.3 Special Shaped Pipe Jacking 10.3.1 Overburden thickness in rectangular jacking pipe should not be less than pipe height. 10.3.2 Rectangular pipe jacking machine should be equipped with attitude correction device, rotation correction device and back soil prevention device. When jacking in sandy soil, a mud adding device should be installed. 10.3.3 When installing pipe jacking machine in jacking pit, the deviation of the center line and elevation should be controlled within ± 10 mm. 10.3.4 During initial jacking, there should be a limit guide device to control the rotation of pipe jacking machine. 10.3.5 In initial jacking, jacking speed should not be too fast and be controlled within 10 mm/min. During normal jacking, jacking speed should be controlled at 20–30 mm/ min. 10.3.6 The pipe jacking machine should be longitudinally connected with front pipes. 10.3.7 For axis control measurement when pipes are jacked in, it is advisable to measure two ends of the same pipe section separately. 10.3.8 The following measures should be taken for rotation control: 1. 2. 3. 4.

Change the direction of rotation of cutter head; Partial grouting; Use balance wings; Pipe jacking machine is equipped with a rotating adjustment device.

10.4 Curve Pipe Jacking

119

10.3.9 When waterproof strip is pasted on pipe section, the elongation rate of waterproof strip should be the same on straight line and at corner.

10.4 Curve Pipe Jacking 10.4.1 Curve pipe jacking with reinforced concrete pipe shall meet the following requirements: 1. During initial jacking, there should be a straight jacking section not less than 20 m long, and it should gradually transition from a straight section to a curved section. 2. The rotation angle α between two adjacent pipe sections should be less than 0.3°. 3. When estimating jacking force, additional coefficient Q of jacking force should be increased for curved pipe jacking compared with straight pipe jacking. Q value should be selected according to Table 10.1. 10.4.2 Steel pipes are not suitable for curve pipe jacking. 10.4.3 When rotation angle between two adjacent pipe sections is greater than 0.5°, a multi-section pipe jacking machine with inter-section deviation correction device should be used. 10.4.4 The width of steel collar at the tail of pipe jacking machine and steel pipe socket should not be less than 160 mm. 10.4.5 Pipe allowable jacking force is related to pipeline curvature and should be adjusted according to the actual situation. 10.4.6 Pipe material for curve pipe jacking should be selected with a shorter pipe section according to the change of curvature radius. 10.4.7 When curvature radius is small, wooden washers with larger thickness and smaller modulus of elasticity should be used. The thickness of wooden washers should be adjusted according to the change of curvature radius and should not be less than 20 mm. The wooden washers should be made of unknotted pine wood. 10.4.8 When grouting for curve pipe jacking, pressure gauge or grouting valve condition should be used to judge the formation of the grout on outer wall of curved pipe, and if necessary, the grouting should be added in time.

Table 10.1 Additional coefficient Q of jacking force for curved pipe jacking Radius of curvature R

300D1

250D1

200D1

150D1

100D1

Q

1.1

1.15

1.2

1.25

1.3

Note D1 is the outer diameter of pipe

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10.4.9 Intermediate jacking station shall have the ability to adjust resultant force center. 10.4.10 The minimum pipe diameter of curved jacking pipes with Intermediate jacking station should not be less than 1400 mm. 10.4.11 For curve pipe jacking in soft soil, the pipeline should be prevented from deviating to curve outside. 10.4.12 The construction measurement in curve pipe jacking shall meet the following requirements: (1) Intermediate measuring stations should be set in pipe, and the number of intermediate measuring stations should not exceed 4; (2) In order to prevent deviation from being too large, measurement positioning of not less than 1 in curve section should be carried out for each pipe jacked; (3) The base point of the guided line should be retested regularly, preferably once every 24 h. 10.4.13 Curvature radius should be calculated according to formula (10.1): R=

L D1 L = tan α X

(10.1)

where, R L α X D1

curvature radius (m); length of pipe section (m); angle between adjacent two pipe sections; maximum gap between adjacent two pipe sections (m); pipe outer diameter (m).

10.5 Vertical Jacking 10.5.1 When multiple pipes are lifted vertically, the work shall be carried out in sequence from far working pit to near working pit. 10.5.2 The estimation of maximum vertical jacking force shall be calculated according to formula (10.2). P = P1 + P2 + P3 + P4

(10.2)

where, P maximum jacking force (kN); P1 water pressure of top cover, which is equal to water pressure of top cover multiplied by pressure area (kN);

10.5 Vertical Jacking

121

P2 breaking power value of top cover (kN), which is taken according to top cove area, 500 kN/m2 for cohesive soil and 800 kN/m2 for sandy soil; P3 frictional resistance between pipe wall and soil, which is the frictional resistance of outer wall of the whole riser (kN); P4 pipe section weight or the weight of the whole riser (kN). 10.5.3 The allowable bearing capacity of soil at bottom shall be checked to determine supporting panel area. 10.5.4 Jacking cap should be provided with gate valves and air holes communicating with the outside. 10.5.5 Water stop device should be installed before jacking. 10.5.6 Effective methods should be used to measure and control jacking verticality. 10.5.7 When installing pipe sections or adding cushion blocks, safety devices should be provided to lock jacked pipe sections to prevent pipe sections from sinking.

Chapter 11

Pipe Jacking Construction Measures

11.1 Corrective Measures 11.1.1 Deviation 1. Use center line deviation and vertical deviation to confirm the space position of pipe jacking machine and pipeline. 2. According to the relationship between forward direction of pipe jacking machine or tool pipe and the design axis of pipeline, there are three deviation states: parallel deviation, front angle deviation and rear angle deviation, as shown in Fig. 11.1. 3. Deviation correction is the process of over-excavating one side soil or forcibly jacking the pipeline to one side to adjust the forward direction of pipe jacking machine or tool pipe, so as to change the route of whole pipeline. 4. The purpose of correcting front angle deviation is to make pipe jacking machine or tool pipe turn into a parallel deviation state. During correction process, the deviation value should be continuously reduced. 5. The purpose of correcting rear angle deviation is to make pipe jacking machine or tool pipe turn into a parallel deviation state. During correction process, the deviation value will continuously increase. 6. The purpose of correcting parallel deviation is to adjust a parallel deviation with larger deviation value to a parallel deviation with smaller deviation value. 11.1.2 Deviation correction method 1. General rules (1) Deviation correction methods include guided correction and mandatory correction. (2) Excavation correction is a guided correction method, and mandatory correction methods include padding method, supporting method, main jacking cylinder method and correction cylinder method. (3) Different correction methods should be used for jacking in different soils and different pipe jacking methods. © China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_11

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11 Pipe Jacking Construction Measures

Fig. 11.1 Deviation state

2. Excavation correction method (1) Suitable for open pipe jacking; (2) It can be used in cohesive soil with good soil quality or sandy soil layer above groundwater level; (3) It should be used when deviation value is not more than 20 mm; (4) Excavate more soil on the opposite side of the pipeline deviation, and do not dig soil on the deviation side, or even leave a sill, which forms resistance, which makes the tool pipe deviate to the over-excavated side with less resistance during jacking to achieve the purpose of correcting deviation. 3. Padding method (1) Suitable for open pipe jacking; (2) It can be used in soils with poor compactness and soft texture; (3) Partially padding steel plates or wood boards on outside of tool pipe to form a mandatory local resistance to force the pipe to turn;

11.1 Corrective Measures

125

(4) After deviation correction completed, the backing plate can be removed, and it can stay in soil when it is not easy to remove. 4. Supporting method (1) Suitable for open pipe jacking construction; (2) It should be used when deviation valve is greater than 20 mm; (3) Supporting method takes effect quickly, and correction range is large. It should be used when the effect of excavation method is not obvious; (4) Use round wood, square wood or 50–100 kN jack as pillar, one end of pillar is supported against the inner wall of tool pipe on pipe other side, and the other end is diagonally supported on the soil in front of pipe. In order to expand pressure bearing area, supporting plate can be cushioned under pillar, and pipe can be jacking forward after support firmly. The resistance generated by pillar diagonal supporting force will compel pipeline to deviate to the side with lower resistance; (5) During pipe jacking, excavation method can be used to correct the deviation, and the support position of pillar needs to be adjusted while jacking; (6) Do not adjust the direction of pipe section too fast, otherwise the support force will be too large, which is easy to cause damage to pipe body; (7) When pipeline returns to normal, support should be removed in time. 5. Main jacking cylinder method (1) For short distance jacking, usually not more than 10 m, main jacking cylinder method can be used; (2) Adjust extension length of main jacking cylinders on both sides or thickness of jacking iron, causing jacking force on one side of pipeline to be greater than that on the other side, so as to achieve the purpose of correcting deviation; (3) Length difference between main jacking cylinders on both sides should be about 30 mm, not more than 100 mm. 6. Correction cylinder method (1) The front and rear sections of pipe jacking machine (or tool pipe) are connected by 4 sets of correction oil cylinders, as shown in Fig. 11.2. By adjusting the extension and contraction status of correction cylinder and changing forward direction of pipe jacking machine, the travel route of entire pipeline can be changed; (2) When correcting deviation upward, adjust the [lower right] and [lower left] of correcting cylinder to “extend” (or adjust [upper right] and [upper left] to “retract”); (3) When correcting deviation to the right, adjust the [upper left] and [lower left] of correcting cylinder to “extend” (or adjust [upper right] and [lower right] to “retract”); (4) When correcting deviation to upper left, first adjust the [lower right] and [lower left] of correction cylinder to “extend”. After correction cylinder in

126

11 Pipe Jacking Construction Measures

place, adjust the [upper right] and [lower right] of correction cylinder to “extend” (Table 11.1). 11.1.3 Matters needing attention in correction: 1. Correction operation is lagging, and it must be stopped in advance to prevent excessive correction; 2. Prior to correction, correction target value and return route should be preset, and correction operations cannot be carried out blindly; 3. When correcting deviations, always grasp position relationship between pipe jacking machine or tool pipe or first section pipe and jacking axis;

Fig. 11.2 Position of correction cylinder

Table 11.1 Correction control table Deviation direction

Correction direction

Cylinder action

Downward

Up

3, 4 stretch or 1, 2 contract

Upside

Down

1, 2 stretch or 3, 4 contract

Right

Left

2, 3 stretch or 1, 4 contract

Left

Right

1, 4 stretch or 2, 3 contract

Remark

11.2 Measures to Reduce Resistance

127

4. During pipe jacking, the overall direction of pipeline should be controlled. It is not necessary to correct deviations that occur every time, and each correction operation does not need to return to the design axis completely. The pipeline end should always be used as control direction to reduce correction number and correction range. Prevent excessive and large swinging of the entire pipeline; 5. When pipeline has both horizontal and vertical deviation, deviation in one direction should be corrected first, and then deviation correction in other direction should be performed; 6. Gravity pipelines have stricter slope requirements, and vertical deviation should be corrected first; for other pipelines, priority should be given to correct deviation in the direction with larger deviation values; 7. When there is a deviation, if it is judged that the change trend of pipeline deviation can return on its own, there is no need to correct deviation; 8. When it is necessary to correct deviations, you should always pay attention to the development trend, and it is strictly forbidden to adjust too much to prevent the opposite result from happening; 9. If deviation exceeds the quality standard and correction target is difficult to achieve, pipe jacking should be temporarily stopped; 10. When correcting deviation, measurement of pipeline direction should be intensified, the head and tail data of pipe jacking machine or tool pipe should be compared, and the regression trend should be grasped in real time to prevent left and right swings; 11. It is strictly forbidden to complete correction deviation task in one time, and deviation should be corrected repeatedly to make pipeline gradually close to return; 12. Correction amplitude and angle should be small each time. Large deviation should be broken down into several small deviations, and segment correction should be carried out to reduce correction amplitude for each segment; 13. Deviation correction must be carried out during pipe jacking and cutter head rotation.

11.2 Measures to Reduce Resistance 11.2.1 Measures must be taken to reduce the frictional resistance of pipe wall during pipe jacking. The method of injecting drags reduction mud between pipe external wall and soil is usually adopted. 11.2.2 Suitable materials should be selected for friction reducing mud according to soil quality and pipe jacking method, and slurry prepared on site should be used after standing for a period of time. 11.2.3 Friction reduction mud should have lower viscosity, higher consistency, better thixotropy, lower friction coefficient and better stability.

128

11 Pipe Jacking Construction Measures

11.2.4 Friction reduction mud usually uses bentonite as main material, and prepared mud should meet the following requirements: 1. The technical parameters of lubricating mud can refer to Table 11.2; 2. When there are acid or alkali ions in groundwater, lubricating mud should be used to prepared locally with groundwater; 3. When soil permeability coefficient is greater than 10−5 m/d, chemical stabilizers should be added; 4. For coarse sand and gravel layers with permeability coefficient greater than 10−2 cm/s, polymer chemical mud should be used. 11.2.5 Non-hydrophilic lubricants such as paraffin wax and waste grease can be used for pipe jacking in water-sensitive formations. 11.2.6 Grouting should have two parts: slurry distribution and slurry supplement. slurry distribution refers to continuous grouting at pipe front end while pipe jacking; slurry supplement refers to properly replenish the loss of friction reduction slurry for the rear pipe after jacking for a period of time. 11.2.7 The setting of grouting hole on pipeline shall meet the following requirements: 1. The pipeline should have 2–5 grouting holes according to different pipe diameters on the same cross section and grouting holes should have exhaust function; 2. The grouting holes on adjacent cross-sections can be arranged in parallel or staggered; 3. Setting of slurry distribution holes: It should be possible to easily form a complete slurry sleeve on pipe outer wall. According to the factors such as soil quality, pipe diameter, jacking length and jacking speed, 3–10 sets of slurry distribution holes are usually set up after pipe jacking machine; 4. Arrangement of slurry supplement holes: concrete pipes should be provided with a group of slurry supplement holes for every 3–5 pipe sections, and the axial spacing of each group of slurry supplement holes for steel pipes is generally 10–25 m; 5. The spacing of slurry distribution holes can be estimated as below formula: Lm = T × V

(11.1)

where, L m spacing of slurry supplement holes (m); T friction reduction mud expiration period (d), usually 6–10 d; Table 11.2 Technical parameter of lubricating mud Specific gravity

1.1–1.5 g/cm3

Water loss

< 25 cm3 /30 min

Static force

Around 100 Pa

Stability

Standing for 24 h without segregation water

Funnel viscosity

> 70 S

pH value

< 10

11.2 Measures to Reduce Resistance

V

129

daily average jacking speed (m/d).

11.2.8 Separate grouting systems should be set up for slurry distribution and slurry supplement for long distance pipe jacking. low-pressure and large-flow grouting pump should be used for slurry distribution, and high-pressure, small-flow grouting pump can be used for slurry supplement. 11.2.9 One-way valve should be installed in grouting hole. When pipe jacking in sandy soil, one-way valve should be installed on the outside of pipe with grouting hole. 11.2.10 The grouting pressure at the outlet of lubricating slurry should be between active earth pressure and passive earth pressure, and should be greater than the groundwater pressure. 11.2.11 Grouting amount can be estimated based on the volume of annular gap between pipe outer wall and surrounding soil. The actual grouting amount in cohesive soil and silt should be 1.5–3 times the estimated grouting amount. The actual grouting amount in coarse sand layer should be more than 3 times the theoretical grouting amount. 11.2.12 The lubricating mud should be simultaneously grouted while pipe jacking, grouting first, then jacking. 11.2.13 Each set of intermediate jacking station shall be provided with a separate grouting hole. Grouting in intermediate jacking station should be synchronized with starting up of intermediate jacking station and grouting shall be continuous during operation. 11.2.14 When pipe jacking in fluid plastic soil with thin overburden, grouting amount should not be too large to prevent ground from uplifting or pipeline from floating up. 11.2.15 When it is close to underground pipelines or other underground structures, grouting pressure should be appropriately reduced. 11.2.16 Each group of grouting holes should be equipped with valves independently; grouting pipe joints should be easy to assemble and disassemble and sealing should be reliable. 11.2.17 In the event of mechanical failure, blockage of grouting pipe, leakage of pipe joints, grouting hole or hole sealing ring leakage, etc., it must be dealt with before jacking can continue. 11.2.18 Before construction, a special plan for lubricating slurry construction should be prepared. The plan should include the following main contents: 1. Mix ratio of lubricating slurry, number of grouting holes, position of grouting holes and grouting pressure; 2. Equipment and installation methods for preparing, storing and transporting lubricating slurry; 3. Grouting process and requirements;

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11 Pipe Jacking Construction Measures

4. Replacement method of lubricating slurry after pass-through; 5. The closing method of grouting hole.

11.3 Measures for Entry and Exit 11.3.1 When entering and exiting the jacking hole, measures should be taken to prevent soil outside hole from collapsing. 11.3.2 The structure and plugging method of water stop ring at entrance shall be determined according to the conditions of engineering geology, pipe diameter, pipe buried depth and groundwater pressure. 11.3.3 When pipeline is below groundwater level, temporary plugging measures should be provided at entrance. 11.3.4 When entering and exiting the jacking hole, corresponding measures should be taken according to different soil conditions: 1. In cohesive soil and high groundwater pressure, water stop device at entrance should be installed, construction speed of entering and exiting jacking hole should be accelerated; 2. In silt soil and there is groundwater, measures can be taken to lower the groundwater level and shorten the time of entering and exiting jacking hole. When dewatering is not possible, soil should be consolidated; 3. In sandy soil, soil outside jacking hole should be reinforced to reduce its permeability coefficient. 11.3.5 In soft soil, the following measures should be taken when entering jacking hole to prevent pipe jacking machine from tilting and sinking: 1. The front end of guiding rail in foundation pit should be as close as possible to jacking hole to shorten suspended length of pipe jacking machine; 2. Entering and exiting jacking hole should be continuous without stopping in the middle; 3. Temporary devices to support pipe jacking machine should be installed in jacking pit. 11.3.6 When exiting jacking hole, the following requirements should be met: 1. Before exiting jacking hole, jacking speed should be reduced, face earth pressure should be reduced to mitigate the adverse effect on receiving pit; 2. Temporary support of pipe jacking machine can be installed in receiving pit to prevent pipe jacking machine from falling; 3. In sandy soil layer with abundant groundwater, soil at the entrance should be consolidated; 4. Opening clearances should be closed immediately after exiting jacking hole to prevent water and soil from flowing into the pit.

11.4 Ground Deformation Control

131

11.4 Ground Deformation Control 11.4.1 For jacking in unstable soil, closed pipe jacking should be selected, and open pipe jacking should not be used. 11.4.2 When ground deformation control is strict, its observation points should be established, and jacking parameters should be adjusted according to the changes in observation data. 11.4.3 Radial overcut and axial overcut amplitude in pipe jacking shall be strictly limited. 11.4.4 Strictly control slag discharge amount and do not discharge excessive slag. 11.4.5 It is not advisable to use large-angle correction. 11.4.6 After penetration, soil consolidation on pipe outer wall should be carried out immediately. 11.4.7 Closed pipe jacking must strictly control soil or slurry chamber pressure. Soil chamber pressure can be controlled according to the following methods: 1. Soil chamber pressure should be set between active earth pressure and passive earth pressure. 2. Active earth pressure can be calculated as follows: Pa = γ H tan2 (45◦ −

ϕ ) 2

(11.2)

3. Passive earth pressure can be calculated as follows: Pp = γ H tan2 (45◦ +

ϕ ) 2

(11.3)

where, Pa γ H ϕ Pp

active earth pressure (kPa); soil gravity (g/cm3 ) (weighted average); distance from pipe center line to ground (m); internal friction angle of soil (weighted average); passive earth pressure (kPa).

4. Increasing jacking speed, reducing excavation speed and grouting into the soil chamber can increase soil chamber pressure. 5. Reducing jacking speed and increasing excavation speed can reduce soil chamber pressure.

132

11 Pipe Jacking Construction Measures

11.5 Intermediate Jacking 11.5.1 When estimated maximum jacking force is greater than the axial compressive strength of pipe or the bearing capacity of supporting panel, intermediate jacking station shall be provided. 11.5.2 The design number of intermediate jacking station can be estimated as follows: n=

π D1 f k (L + 50) −1 0.7 × f 0

(11.4)

where, n number of intermediate jacking stations (in integer); f 0 allowable jacking force of intermediate jacking station (kN). 11.5.3 Intermediate jacking station shall meet the following requirements: 1. Output jacking force of intermediate jacking station should not be greater than jacking force that pipe section can withstand; 2. Allowable rotation angle of intermediate jacking station should be greater than 1.2°; 3. The action center of resultant force of intermediate jacking station should be adjustable; 4. Intermediate jacking station should meet the requirements of high rigidity, no deformation and convenient installation; 5. Seals in intermediate jacking station should have good sealing performance, wear resistance and long service life, and should avoid the entry of grout, groundwater, sand or soil particles; 6. Independent hydraulic oil supply system should be installed for each intermediate jacking station. 11.5.4 The installation of cylinder in intermediate jacking station should meet the following requirements: 1. The cylinders in intermediate jacking station should be fixed on the combined frame and evenly arranged around pipe, symmetrically distributed with pipe midvertical line, and the action point of resultant force should be on pipe mid-vertical line; 2. The number of cylinders in intermediate jacking station should be set as many as possible, the output thrust of each cylinder should not be greater than 1000 kN, and the stroke should be 200–500 mm; 3. The specifications and performance of each cylinder in intermediate jacking station should be the same. When specifications are different, the stroke should be synchronized, and cylinders with same specification should be arranged symmetrically;

11.5 Intermediate Jacking

133

4. The number of cylinders installed in intermediate jacking station should be estimated and determined according to jacking force of unit length, and there should be a safety reserve; 5. The jacking force margin for the first set of intermediate jacking station should not be less than 40%, and the others should not be less than 30%; 6. The oil circuits of multiple oil cylinders in the same intermediate jacking station should be connected in parallel, and oil cylinders should have independent control switches for oil inlet and outlet; 7. After installation, check whether each component is normal, and jacking test should be conducted before formal use; 8. The jacking force exerted by main jacking cylinder should always be greater than the jacking force exerted by one set of intermediate jacking station. 11.5.5 When there are multiple sets of intermediate jacking station, they should be grouped for operation and started sequentially backward from pipe jacking machine. When one set of intermediate jacking station is extended, the others should remain stationary. After all intermediate jacking stations completes jacking in sequence, main jacking cylinder will jack again. 11.5.6 After penetration, intermediate jacking station shall be closed, which shall meet the following requirements: 1. When closing, all internal components of intermediate jacking station should be removed, and intermediate jacking station should be closed with the help of the intermediate jacking station after it or the main jacking cylinder; 2. The closing should be carried out from the front to the back; 3. After closing, the intermediate joints should be closed; 4. The strength and anti-corrosion performance of pipes at intermediate jacking station should meet pipe design requirements. If it fails to meet the requirements, it should be treated; 5. After intermediate jacking station for steel pipe is closed, an inner ring should be welded on the weak section. 11.5.7 When the thrust of main jacking cylinder reaches 40–60% design thrust of intermediate jacking station, the first intermediate jacking station should be installed; after that, whenever the thrust of main jacking cylinder reaches 70–80% design thrust, one set of intermediate jacking station should be installed. 11.5.8 When the thrust of main jacking cylinder reaches 80% designed thrust of intermediate jacking station, it shall be activated. 11.5.9 For extra-long distance pipe jacking, intermediate jacking station should adopt a replaceable sealing device with reliable sealing performance, adjustable sealing ring compression. 11.5.10 In curve section or deviation section, the resultant force center of intermediate jacking station should be adjusted in time during jacking to ensure that its rotation angle does not increase.

134

11 Pipe Jacking Construction Measures

11.6 Mucking Transportation 11.6.1 Pipe transportation 1. There are usually three methods for muck transportation in pipes: truck transportation, mud pipeline transportation and muck pipeline transportation; 2. Pipe transportation should be comprehensively considered according to factors such as soil properties, type of pipe jacking machine, working space in pipe, excavation amount, jacking length and other factors: (1) Truck transportation should be used in hand excavation pipe jacking, extrusion pipe jacking, and short to medium distance earth pressure balance pipe jacking; (2) Mud pipeline transportation should be used in water flushing pipe jacking, slurry balance pipe jacking, air pressure balance pipe jacking and medium to long distance earth pressure balance pipe jacking; (3) Muck transportation should be used in medium to long distance earth pressure balance pipe jacking; (4) Sandy soil should be transported by mud pipeline transportation; cohesive soil should be transported by muck pipeline transportation. If soil quality is not suitable, it should be improved. 3. Pay attention to the following matters when using mud pipeline transportation: (1) Mud pipeline must use mud as the medium and mud pumps to provide transportation power for muck; (2) When conveying sandy soil, it is not advisable to use clean water as medium; (3) With mud pipeline in manual pipe jacking and earth pressure balance pipe jacking, a mud mixer is required to mix muck and mud evenly; (4) When mud pipeline transportation is used, a mud separation sedimentation tank should be set on ground, and its volume should be determined according to mud separation speed and discharge volume; (5) The use of mud separator can speed up the mud separation speed and reduce the volume of mud separation sedimentation tank; (6) Waste mud should be treated before discarded and discharged to avoid environmental pollution. 4. Pay attention to the following matters when using truck transportation: (1) Truck loaded with muck first passes through pipeline to jacking pit, then uses vertical transportation equipment to hoist truck to ground for dumping; (2) When moving truck in pipeline, it can be pushed by manpower or pulled by machinery. 5. Pay attention to the following matters when using muck pipeline transportation: (1) Pipeline transportation of muck is suitable for soil with good flow plasticity; (2) When flow plasticity is poor, soil should be improved for flow plasticization;

11.7 Anti-rotation Measures

135

(3) Pipeline transportation of muck should be used in hand-digging pipe jacking and earth pressure balance pipe jacking with long jacking distance. 11.6.2 On-site transportation of muck 1. The temporary storage site for muck should be set up near the jacking pit. 2. According to excavation volume, transportation distance, and site conditions, rickshaws and motor vehicles can be used to transport muck. 3. The muck should be covered with dust prevention. 4. The mound yard should have good drainage and traffic conditions.

11.7 Anti-rotation Measures 11.7.1 Viewed from the rear of pipe jacking machine, when it rotates clockwise, it is called right turn, and when it rotates counterclockwise, it is called left turn. 11.7.2 The following measures shall be taken to prevent pipe jacking machine from rotating: 1. When initial jacking into entrance, jacking speed should be slowed down and cutting depth of cutter head should be reduced; 2. The head pipe should be connected as soon as possible to increase the friction torque; 3. According to the rotation trend of pipe jacking machine, cutter head should be rotated alternately in forward and reverse directions; 4. When starting jacking, cutter head should be started before jacking pipe, and when jacking is stopped, pipe jacking should be stopped first and then cutter head be closed; 5. When entering entrance, measures such as anti-rotation clamping board, steel cable or wing plate can be used to prevent pipe jacking machine from rotating. 11.7.3 The use of anti-rotation card board should meet the following requirements: 1. Anti-rotation clamping board should be installed before pipe jacking machine enters the jacking hole; 2. Anti-rotation clamping board should be installed on the tail shell of pipe jacking machine; 3. Anti-rotation clamping board should be close to guiding rail in foundation pit; 4. Anti-rotation clamping board should be removed before entering jacking hole to prevent scratching the rubber plate of water stop ring. 11.7.4 The use of anti-rotation steel cables shall meet the following requirements: 1. Steel cables are used to bind pipe jacking machine to guiding rails in foundation pit; 2. Square timbers shall be padded inside steel cable; 3. Steel cable should be tightened with hand chain hoist;

136

11 Pipe Jacking Construction Measures

4. As pipe jacking machine enters the jacking hole, steel cable should be gradually moved back, and all steel cables should be removed before pipe jacking machine enters the jacking hole. 11.7.5 The use of anti-rotation wing panels shall meet the following requirements: 1. Anti-rotation wing plate should be used to prevent pipe jacking machine from rotating after entering the jacking hole; 2. Retractable anti-rotation wing plate should be used to facilitate entry and exit operations; 3. When constructing in sand and gravel layer, anti-rotation wing plate should be thickened and shortened.

11.8 Measurement 11.8.1 Measurement control 1. Before construction, the delivered measurement baselines and base points should be checked. 2. Before pipe jacking, ground and underground measurement and control systems should be established about pipeline design centerline and foundation pit, as shown in Fig. 11.3. The control points should be located in locations that are not easily disturbed, have clear sight and are easy to check, and protective measures should be taken. 3. The instruments and tools used for measurement should be checked and corrected, their accuracy should conform to the current national standards. 4. Temporary benchmarking points introduced by ground benchmarking points should be set in foundation pit, and should be checked regularly. 5. Pipe jacking positioning and guiding instrument should be installed firmly without shaking or collision. 11.8.2 Jacking measurement 1. The following parameters must be measured during pipe jacking: (1) (2) (3) (4) (5)

Vertical deviation of jacking direction; Horizontal deviation of jacking direction; Rotation angle of pipe jacking machine; Pitch value of pipe jacking machine; Jacking length.

2. In jacking, measurement method combining continuous measurement and intermittent check should be used. Continuous measurement usually uses a laser pointer or automatic positioning equipment to indicate jacking direction without interruption; intermittent check means that pipeline is adjusted for certain jacking distance and the measurement result is compared with guidance positioning data.

11.8 Measurement

137

Fig. 11.3 The position of axis control point in jacking pit

3. Measuring light target in pipe jacking machine should be close to front end. 4. Measurement during pipe jacking should meet the following requirements: (1) During initial jacking, measurement should be densified, and it should be measured and recorded once every 0.5 m of footage; (2) During normal jacking, measurement record should not be less than 1 time for every 1.0 m footage; (3) When correcting deviation, measurement should be densified and the measurement record should not be less than 1 time for every 0.5 m of footage; (4) Before exiting the jacking hole, measurement should be densified and it should be recorded once every 0.5 m of footage. 5. Guiding method in straight pipe jacking should be selected according to the following conditions: (1) When pipeline length is less than 50 m, manual pulling method can be used; (2) When pipeline length is less than 300 m, laser pointing method should be adopted; (3) When pipeline length exceeds 300 m, measuring station should be set in pipeline, transfer station measurement by traverse method shall be used; (4) When pipeline length exceeds 500 m, automatic measuring guide device should be used. 6. In curve jacking pipe, traverse method shall be used, and automatic measuring guide device should also be used. 11.8.3 Pass-through measurement 1. Measurement items include pipeline center line deviation, elevation deviation and pipe-to-pipe dislocation. 2. There should be no less than 1 measuring point per pipe section or per 5 m length.

138

11 Pipe Jacking Construction Measures

11.8.4 Measures for measuring elevation deviation in pipe are as follows: 1. Usually use level to measure; 2. When pipeline length exceeds 200 m, water level connector can be used; 3. When pipe height difference along pipeline axis is greater than 1/3 of pipe inner diameter, a micro manometer should be used. 11.8.5 Measurement results should have accuracy analysis and provide the maximum possible measurement error. 11.8.6 Original record of measurement should be kept intact.

11.9 Pipe Lowering Measures 11.9.1 Pipes, fittings, etc. transported to the site should be reasonably arranged for temporary storage. The site should be level and the storage site for water supply pipes should be cleared of sundries that impede sanitation. 11.9.2 When hoisting and transporting pipes, protective measures should be taken for pipe joints and anti-corrosion layer. 11.9.3 Before lowering pipes, take the following measures: 1. Lowering pipe method shall be determined according to the specific conditions of worker’s operating proficiency, pipe weight and length, construction environment, working pit depth and lifting equipment; 2. Safety measures should be formulated and trained personnel should act as on-site commanders; 3. Tools, machinery and equipment used in lowering shall be inspected and can be used only when they meet technical and safety requirements; 4. Foundation pit should be inspected, the height of guide rail in foundation pit and the width of foundation pit should meet construction requirements; 5. The elevation and location of pipeline should be reviewed; 6. The specifications and quality inspections of pipes and fittings should be carried out one by one; 7. It is advisable to clean pipe inner and outer walls. 11.9.4 The following measures should be taken when lowering pipes: 1. Workers in pit should avoid the position for lowering pipe, and it is strictly forbidden to stand under pipes; 2. Pipe body shall not collide with pit wall and the pipes in pit. 11.9.5 When using a crane to lower pipes, the following requirements shall be met: 1. The crane operator should survey the site in advance, and determine the distance between crane and pit sides, pipe placement position and other coordination matters according to working pit depth, soil quality, and environmental conditions;

11.10 Power Supply Measures

139

Table 11.3 The safe distance when crane is working on one side of overhead transmission line Transmission line voltage (kV) The shortest distance along the The shortest distance along the vertical direction of the horizontal direction of the transmission line (m) transmission line (m) F ≥ 0.6, the monitoring frequency should be increased, the reason should be found, and remedial measures should be prepared; (3) Alarm: When F ≥ 0.8, construction should be temporarily stopped, monitoring frequency should be increased, the cause should be found out, and remedial measures should be implemented. Table 13.1 Early warning value of instrument monitoring Serial number

Level

Warning status

1

Safe

Less than 60% of the control value

2

Early warning

The control value is between 60 and 80%

3

Warning

Over 80% of the control value

146

13 Construction Monitoring

13.5 Monitoring Items 13.5.1 Patrol inspection of foundation pit 1. Patrol inspection items for foundation pit excavation shall include: (1) Whether there is any difference between the soil exposed by excavation and that in geotechnical survey report; (2) Whether excavation is consistent with design requirements and whether there is over-excavation; (3) Discharge of surface water and groundwater in foundation pit; (4) Operation of drainage facilities in foundation pits; (5) The stacking situation on ground around foundation pit. 2. Patrol inspection items of foundation pit supporting structure shall include: (1) The forming quality of supporting structure; (2) Cracks and deformation of the top, side walls and bottom of supporting structure; (3) Ground cracks and deformations within the scope of construction impact or within 3 times the depth of foundation pit; (4) Deformation of inner support in foundation pit; (5) Cracks, deformation, and slippage of soil on the upper part of entrance and on the back; (6) Soil surging, quicksand, running water, piping, etc. from bottom plate and side walls of foundation pit. 3. Patrol inspection items of surrounding environment around foundation pit shall include: (1) Whether underground pipeline is damaged or leaked; (2) Whether there are cracks or deformations in surrounding structures and underground structures; (3) Whether there are cracks and deformations on surrounding roads and surfaces. 4. Patrol inspection items of monitoring facilities includes: (1) (2) (3) (4)

Conditions of reference points and monitoring points; Obstacles that affect monitoring work; Use and protection of monitoring equipment; Monitoring health, protection, work of personnel.

13.5.2 Instrumental monitoring of foundation pits 1. Foundation pit classification: The safety level of foundation pit divided into three levels (Table 13.2) according to excavation depth h of the working pit, relative distance ratio α between adjacent buildings (structures), pipelines and pit sides, engineering geology, hydrogeological conditions and the severity of damage.

13.5 Monitoring Items

147

Table 13.2 Safety classification of foundation pit Excavation depth h (m)

Environmental and engineering geology, hydrogeological conditions α < 0.5 I

0.5 ≤ α ≤ 1.0 II

III

I

h > 15

Level 1

Level 1

10 < h ≤ 15

Level 1

Level 1

h ≤ 10

Level 1

Level 2

Level 2

II

α > 1.0 III

I

II

III

Level 2

Level 1

Level 2

Level 2

Level 3

Level 1 Level 3

2. Instrumental monitoring items: vertical and horizontal displacement at top of foundation pit, and vertical displacement of ground surface around foundation pit. 3. Monitoring control value: When project is not given a monitoring control value, monitoring control value of foundation pit and surrounding environment can be determined according to the “Technical standard for monitoring of building excavation engineering” (GB 50497-2009), and combined with actual project, refer to Table 13.3. 4. Requirements for monitoring point layout (1) Monitoring points for horizontal and vertical displacement of foundation pit should be set on the top of foundation pit supporting structure; (2) Layout range of monitoring points for vertical displacement of ground surface around foundation pit should be 1–3 times the depth of foundation pit; (3) Vertical displacement monitoring lines of ground surface around foundation pit should be laid along central axis of foundation pit, and there should not be less than 4 monitoring lines for each foundation pit; (4) Monitoring points are set on monitoring line, and the distance between the monitoring points should not be greater than 3 m. 5. Requirements for reference point layout (1) Reference points should be set in a stable area that is not affected by construction; (2) Reference points should be set outside the range of 3 times excavation depth of foundation pit; (3) There should be visibility between reference point and each monitoring point; (4) The number of reference points should not be less than 2. 13.5.3 Patrol inspection items for pipe jacking 1. Inspection of pipe jacking related equipment (1) Operating status of pipe jacking machine and main jacking equipment; (2) Operating status of grouting system; (3) Operating status of intermediate jacking station;

Monitoring items

Top horizontal displacement

Top vertical displacement

Vertical displacement of surrounding ground

Serial number

1.

2.

3.

25–35

10–20

25–30

–

0.1–0.2

0.2–0.3

Relative depth control value of foundation pit (%)

2–3

2–3

2–3

50–60

25–30

40–50

Absolute value (mm)

–

0.3–0.5

0.5–0.7

Relative depth control value of foundation pit (%)

Cumulative value

Absolute value (mm)

Secondary foundation pit

Cumulative value

Rate of change (mm d−1 )

First-level foundation pit

Allowable deformation value

Table 13.3 Reference monitoring control value of foundation pit supporting structure

4–6

3–4

4–6

Rate of change (mm d−1 )

60–80

35–40

60–70

Absolute value (mm)

_

0.5–0.6

0.6–0.8

Relative depth control value of foundation pit (%)

Cumulative value

Three-level foundation pit

8–10

4–5

8–10

Rate of change (mm d−1 )

148 13 Construction Monitoring

13.5 Monitoring Items

(4) (5) (6) (7)

149

Operating status of ventilation facilities in pipeline; Operating status of in-pipe lighting and emergency lighting facilities; Operation status of vertical transportation equipment; Operating status of measuring instrument.

2. Inspection of pipe jacking conditions (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14)

Jacking deviation, correction operation and correction result; Stability and bearing capacity of back; State of the sealing ring; State of guide rail in foundation pit; State of foundation pit supporting structure; State of drainage facilities; Air quality in pipeline and foundation pit; Physical condition of construction personnel; Whether jacking record is complete, timely and objective; Changes in soil quality and groundwater during jacking; Whether jacking speed is appropriate; Whether jacking distance is equivalent to the amount of soil discharged; Freshness of air in pipeline; Whether there are any obstacles in pipe that are not conducive to escape.

3. Inspection of pipeline (1) (2) (3) (4) (5)

Appearance of pipeline; Bearing capacity and damage degree of pipeline; Joints at pipe mouth; Whether change of joint width is consistent with deviation of pipeline; Water or mud leakage in pipe.

4. Inspection of surrounding environment and above-ground or underground structures (1) Distance change between pipe jacking machine and structures; (2) Influence degree of pipe jacking machine operation on underground pipelines and structures; (3) Whether pipeline is damaged or leaked; (4) Whether structure is damaged or cracked, whether original crack is widened or increased, and whether structures are obviously displaced or deformed; (5) Whether there are cracks, deformations, or slurries on road and ground. 5. Mud inspection in pipe jacking (1) (2) (3) (4) (5) (6)

Whether pipeline is mud leakage or running; Whether grouting pipeline is leaking; Whether mud preparation ratio is reasonable; Whether mud preparation method is appropriate; Whether mud quality is qualified; Whether lubricating mud injection is synchronized with pipe jacking;

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13 Construction Monitoring

(7) Whether filling is timely; (8) Whether mud is full; (9) Whether there is mud on surface. 6. Inspection of monitoring facilities (1) (2) (3) (4)

Status of reference points and monitoring points; Whether there are obstacles that affect monitoring work; Monitoring facilities and their protection status; Status of monitoring instrument.

7. Inspection of other related items (1) (2) (3) (4) (5) 6)

Weather factors such as dewatering, snowfall, low temperature and wind; Surrounding factors that affect project normal progress; Impact degree of construction on surrounding residents and social traffic; Whether engineering safety guarantee facilities are intact and complete; Whether emergency rescue equipment is equipped reasonably; Distribution of social rescue agencies.

13.5.4 Instrument monitoring items for pipe jacking 1. Pipeline deviation (1) Pipeline centerline deviation; (2) Pipeline elevation deviation; (3) Dislocation at pipe joints. 2. Jacking force changes (1) Main jacking force; (2) Jacking force of intermediate jacking station. 3. Mud (1) Grouting pressure; (2) Outlet pressure; (3) Mud flow. 4. Earth chamber pressure 13.5.5 Instrument monitoring of surrounding environment 1. Monitoring and control value of surrounding environment shall be determined according to the requirements of relevant competent authorities. If there is no specific requirement, please refer to Table 14.2. 2. When determining the alarm value of surrounding buildings (structures), the superposition of original deformation of building (structure) and additional deformation caused by construction should be considered. 3. Instrument monitoring items of surrounding environment include:

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151

(1) Vertical displacement of ground surface shall be monitored for pipe jacking project; (2) For bridges, horizontal and vertical displacements of bridge deck and tilting displacement of bridge piers should be monitored; (3) For highways and railways, vertical displacements should be monitored; (4) For fences, line poles and high towers, vertical and tilting displacement should be monitored; (5) For underground pipelines, vertical and horizontal displacement should be monitored; (6) For high buildings, vertical, horizontal and tilt displacement should be monitored; (7) When it is inconvenient to set up monitoring points, indirect monitoring should be adopted; (8) In key areas, ground penetrating radar can be used to detect soil compactness on outer wall of pipe.

Chapter 14

Engineering Quality and Acceptance

14.1 General Provisions 14.1.1 The unit in charge of construction makes completion documents and submits application for inspection to construction unit. The construction unit shall organize professional project management unit, design unit, supervision unit, unit in charge of construction and other related units to check and accept the project and engineering data. 14.1.2 For completion acceptance of pipe jacking, the industry pipeline acceptance specifications shall be implemented according to the requirements of different industries. 14.1.3 Before project is completed and accepted, construction site should be cleaned and restored, as well as necessary visual inspection and sealing test.

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14.2 The Requirment of the Pipeline Appearance Quality Pipeline appearance should meet the following requirements: 1. Pipe is clean and free of debris and oil; 2. Pipe section is not damaged, and defective part should be repaired densely and surface should be smooth; 3. Smooth, no sudden change, no deformation in pipeline; 4. The filling in gap of pipe joint is full, dense, and flush with pipe inner surface; 5. Pipeline is connected tightly and firmly with jacking hole in working pit, and there is no water leakage or sand gushing; 6. Grouting holes are all closed without water seepage or mud leakage; 7. Joint rubber ring is installed correctly without displacement or falling off; 8. There is no water seepage in pipes and pipe joints.

14.3 The Requirment of the Pipeline Allowable Deviation The allowable deviation shall meet the requirements of Table 14.1.

14.4 Requirements for Surrounding Environment Impact The impact of pipe jacking on surrounding environment shall meet the following requirements: 1. When crossing road, there should be no visible cracks on road surface; 2. When crossing dams and underground facilities, no damage and water seepage shall be caused; 3. When crossing railways, subways, highways and other above-ground and underground facilities, the cumulative deformation shall comply with the regulations of relevant authorities. If there are no specific regulations, please refer to Table 14.2.

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Table 14.1 Allowable deviation of pipeline jacked Check item

Allowable deviation (mm)

Check frequency Scope

1

2

3

Straight pipe jacking horizontal axis Inner bottom elevation of straight pipe jacking

Jacking length < 300 m

50

300 m ≤ Jacking length < 1000 m

100

Jacking length ≥ 1000 m

L/10

Jacking length < 300 m

D < 1500

+ 30, − 40

D ≥ 1500

+ 40, − 50

300 m ≤ Jacking length < 1000 m

+ 60, − 80

Jacking length ≥ 1000 m

+ 80, − 100

Curved R ≤ 150 × D1 pipe jacking horizontal axis R > 150 × D1

Horizontal curve

150

Vertical curve

150

Inspection method

Points

Per one pipe point section

Theodolite or hanging center line ruler Level

Theodolite

Compound 200 curve Horizontal curve

150

Vertical curve

150

Compound 150 curve 4

Elevation R ≤ 150 × D1 of inner bottom of curved top pipe R > 150 × D1

Horizontal curve

+ 100, − 150

Vertical curve

+ 150, − 200

Level

Compound ± 200 curve Horizontal curve

+ 100, − 150

Vertical curve

+ 100, − 150

Compound ± 200 curve (continued)

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14 Engineering Quality and Acceptance

Table 14.1 (continued) Check item

Allowable deviation (mm)

Check frequency Scope

5

Stagger between adjacent pipes

Steel pipe, glass steel pipe

≤2

Reinforced concrete pipe

15% wall thickness, ≤ 20

Inspection method

Points Ruler

6

Circumferential deformation of steel pipe ≤ 0.03 × D and FRP pipe

7

Wrong mouth at both ends when aligning 50

Note D is pipe inner diameter (mm); L is jacking length (m); D1 is pipe outer diameter (mm); R is design radius of curvature of curved jacking pipe Table 14.2 Allowable deformation reference value of the surrounding environment Item

Object

Cumulative value Deformation value (mm)

Tilt

Rate of change (mm d−1 )

–

500

1

Groundwater level change

1000

2

Pipeline displacement

Pressure

10–30

–

1–3

Non-stress

10–40

–

3–5

Rigid pipe

Flexible pipeline 3

Building

10–40

–

3–5

Maximum settlement

10–60

–

–

Differential settlement

–

2/1000

0.1H/ 1000

4

Embankment

Maximum settlement

30

–

3

5

Ordinary highway

Maximum settlement

20

–

2

6

Highway

Maximum settlement

15

–

2

7

Railway

Maximum settlement

5

–

1

Remark

Observe the measurement point data directly

Note H is structural height of the building; the third cumulative value is the smaller of the maximum settlement and the differential settlement

Chapter 15

Health, Safety and Environmental Protection Management

15.1 Health Management 15.1.1 Labor Protection 1. It shall meet the requirements of national and local labor protection laws and regulations. 2. Construction personnel should be equipped with corresponding labor protection equipment.

15.1.2 Healthcare 1. Medical treatment: Construction site should be equipped with medical kits and corresponding emergency medicines should be equipped according to the construction area, season and operation characteristics. 2. Health care: A health care system for employees’ health inspection, disease prevention, dietary hygiene, etc. should be established and implemented in earnest. 3. Public health (1) Pay attention to environmental sanitation of station, and clean up the garbage regularly; (2) The dormitory should be disinfected, kept clean and tidy, and measures to prevent rodents, flies and mosquitoes should be taken; (3) The dining room and kitchen should be kept clean and tidy, tableware must be disinfected, and unidentified and spoiled food should not be consumed; (4) Maintain personal hygiene, take a bath and change clothes frequently to prevent epidemics.

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15.2 Security Management 15.2.1 Basic Regulations 1. Construction personnel should carefully survey site, understand the various underground facilities, pipeline distribution and surrounding environment of construction site, and formulate targeted safety technical measures. 2. Before construction, unit in charge of construction shall notify the use and management unit of relevant buildings (structures) along the route, explain to them the construction plan, and protection measures for existing buildings (structures). At the same time, corresponding emergency plans shall be made according to the nature of the buildings (structures) to be crossed. 3. Regulations and systems to ensure safe production shall be established and implemented, and records of safety activities shall be kept. 4. Full-time or part-time safety officer should be set up, and safety officer shall receive safety training and pass the examination. 5. Safety production vocational training shall be provided for employees on duty. Special work must be certified to work, and the site safety inspection shall be carried out regularly to eliminate hidden dangers, and safety production and accident life-saving education should also be carried out. 6. Full attention should be paid to the natural environment of construction area to prevent natural disasters such as floods, mountain fires, landslides, and mudslides from damaging people and property. 7. Blasting operations should comply with the regulations of “Safety regulations for blasting” (GB6722-2014). 8. When temperature is higher than 38 °C or lower than – 30 °C, construction operations should be stopped and protective measures should be taken. 9. No alcohol is allowed before and during work. When entering construction site, you must wear appropriate work clothes, work shoes and a safety helmet. It is not allowed to work bareback, barefoot or wear slippers. 10. It is strictly forbidden to store toxic and corrosive chemicals on construction site for a long time. When using these chemicals, you must wear protective equipment in accordance with relevant regulations. 11. Construction site should be set within approved scope, site and roads should not be occupied arbitrarily. 12. During construction in streets, highways, railways and rivers, traffic reflective vests and safety helmets shall be worn. 13. During construction in urban areas, eye-catching safety signs must be set up, fences and warning lights must also be set up at the same time. 14. When constructing on roadside, clear traffic signs shall be set up, and special personnel shall be assigned to clear the traffic. 15. It is strictly forbidden for non-operators to tamper with mechanical equipment and electrical facilities at construction site.

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159

16. Construction machinery and electrical equipment should be debugged and inspected before construction.

15.2.2 Regulations on Safe Use of Electricity 1. Lighting voltage in pipeline shall not exceed 36 V. 2. Power distribution box and lighting distribution box should be set up independently. 3. Each electrical equipment should be independently equipped with a switch box, implement the configuration of “one machine, one gate and one leakage protector”. 4. Mobile distribution box and switch box should be installed on a fixed bracket, and have measures to prevent moisture, rain and sun. 5. Electrical equipment should be protected to zero or grounded according to requirements of power supply system. Ground resistance should be less than 4 Ω. 6. Outdoor lighting should use waterproof lamps. 7. When repairing electrical equipment, power supply should be cut off, and a warning sign should be hung up or guarded by a special person. 8. Electricity for construction strictly abides by the regulations of “Safety Code for Electricity Supply and Power on Construction Site” (GB 50194-2014). 9. The use of hand-held power tools should comply with the “Safety Technical Regulations for Management, Use, Inspection and Maintenance of Hand-held Power Tools” (GB/T 3787-2006).

15.2.3 Safety Regulations for Electric Welding 1. The welding machine shall be used in strict accordance with the parameters marked on the nameplate and do not use it with overload. 2. Before using welding machine, you should check that the welding machine is connected correctly, the current range meets the requirements, the shell is reliably grounded, and there is no foreign object in the welding machine before it can be closed. 3. When working, welder iron core should not vibrate strongly, and screws of pressing iron core should be tightened. 4. Temperature of welding machine and current regulator during work should not exceed 60 °C. 5. Maintenance should be done to keep the inside and outside of welding machine clean to ensure good insulation between welding machine and welding cord. If there is any damage or burn, it should be repaired immediately.

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6. Electrician should regularly check technical condition of welding machine’s circuit and insulation performance of welding machine. If there is any problem, it should be eliminated in time. 7. During operating, wear labor protection article, such as work clothes, work hats, gloves and foot covers, etc. 8. In welding and cutting workplaces, there must be fire protection equipment, such as fire hydrants, fire extinguishers, sand boxes, and buckets filled with water. 9. When welding in pipeline, a ventilation device must be provided. 10. It is strictly forbidden to conduct electric welding or cutting in containers that have been sprayed with paint, rubber, fuel, etc. 11. When conducting electric welding in fire-prohibited places, a fire permit must be obtained, and guardianship and fire prevention measures must be in place before operation can be performed. 12. When working at heights, construction personnel should wear safety belts and comply with relevant regulations for working at heights. 13. During construction, construction personnel should be careful to avoid electric shock and be protected from arc light, metal splash and other injuries. 14. After welding or cutting work is completed, surrounding area of welding site must be carefully inspected to confirm that there is no fire hazard before leaving.

15.2.4 Gas Welding Safety Regulations 1. Before operation, you must wear work clothes, work hats, gloves and protective glasses as required to prevent arc damage and burns. 2. Oxygen bottle filled with oxygen should be lifted gently and slowly, bottle mouth should not be lifted. Oxygen bottle should not be exposed to the sun or close to high temperatures and should be kept away from fire sources and flammable materials. 3. Distance between acetylene gas bottles, oxygen bottles and welding objects shall not be less than 5 m. Acetylene pipes and oxygen pipes must not be mutually used, pipes and joints must be firmly connected. 4. When igniting, oxygen bottle should be turned on first, and then a small amount of acetylene gas bottle; when it is extinguished, acetylene gas should be turned off first, and then oxygen gas. When flashback occurs, acetylene gas bottle should be turned off first, and then oxygen gas bottle. 5. When welding is suspended, gas valve of acetylene gas bottle and main valve of oxygen bottle must be turned off. 6. Before performing gas welding, a fire permit must be obtained.

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15.2.5 Fire Protection Regulations 1. A certain number of fire extinguishers, sand boxes, shovels and other fire extinguishing appliances should be provided in construction site, and they are not allowed to be used for other purposes. 2. To remove weeds around site, width of fire path should be greater than 5 m. 3. When constructing in forest and grassland areas, preventive measures shall be taken in accordance with relevant local fire protection regulations. 4. When using an open flame for heating, a proper safety distance must be ensured and furnace base must be lined with masonry or heat insulation board. 5. The exhaust pipe of internal combustion engine and the chimney of heating stove should take into account the seasonal wind direction and extend more than 0.5 m from appropriate side of building, and should be installed with heat insulation boards and fire hoods. 6. Attention should be paid to burning situation of heating stove, and no flames should be allowed to escape and no oil should be used to support combustion. Unextinguished ashes shall not be dumped casually. The fire must be completely extinguished before personnel evacuation 7. It is forbidden to smoke and use open flames in construction site. Cigarette butts are not allowed to be littered in control room, working pit, and pipes. 8. Oil and other flammable materials must be properly kept, and fireworks are strictly prohibited. 9. When oil catches fire, fire extinguishers and sand should be used to extinguish the fire. Water is strictly prohibited. When electrical appliance catches fire, power supply should be cut off first, then put out the fire.

15.2.6 Windproof Regulations 1. During construction period, special personnel shall be assigned to inquire and record the weather forecast to prevent sudden attacks by strong winds. 2. Safety isolation facilities shall be set at construction site to evacuate immediately in case of safety accident occurs. 3. Carrying out regular wind-proof safety inspections for vertical hoisting machinery. 4. After working at heights, all parts, tools, and waste must be cleaned up to prevent people from being blown off by strong winds. 5. Before arrival of strong winds, construction area and equipment should be inspected, handled, and temporarily reinforced according to wind classification. Items that cannot be reinforced should be transported to the building in time. 6. All high-altitude operations should be stopped when 6 level wind, all operations should be stopped when 8 level wind, all activities should be stopped and evacuation preparations shall be made when 9 level wind, and the construction personnel shall evacuate to the safe area in time before the gale above force 10 comes.

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7. When stopping construction during strong winds, power supply should be cut off, and safety conditions of construction site enclosures, vertical hoisting machinery and other equipment should be closely monitored. 8. After strong wind, construction facilities, machinery and power lines should be inspected. When supporting structure is damaged, it must be removed or reinforced immediately.

15.2.7 Lightning Protection Regulations 1. Before thunderstorm season, a comprehensive inspection of engineering facilities should be carried out. Construction sites with higher terrain and construction machinery above ground must be equipped with lightning protection devices, and grounding resistance value should meet specified requirements. 2. During thunderstorms, lifting operations and high-altitude operations are prohibited. 3. When lightning strikes, construction personnel should: (1) They should stay indoors, close doors and windows, and outdoor workers should immediately hide in the building; (2) Do not use televisions, stereos, computers and other electrical appliances without lightning protection measures or insufficient lightning protection measures, and do not use faucets; (3) Do not touch antennas, water pipes, barbed wire, metal doors and windows, exterior walls of buildings, etc., stay away from electric wires and other live equipment or other similar metal devices; (4) Do not use telephones, mobile phones, or internet; (5) Stay away from water, open fields, mountain tops, and building tops in the open air, and find a place to hide. If you cannot escape, stay away from trees, poles, and not close to objects with good conductivity; (6) Flammable materials in open containers should not be handled; (7) Do not use umbrellas, do not carry shovel, steel bars, etc. on your shoulders, you should immediately take off metal objects on your body; (8) It is not suitable to drive motorcycle or ride bicycle; (9) If you feel skin irritation or hair erection, you should avoid it quickly. If you can’t avoid it, you should squat on ground immediately, put your feet as close as possible, put your hands on your knees, keep your chest close to your knees, and lower your head as much as possible to reduce the risk of lightning strikes. 4. Once someone is struck by lightning, ask for rescue. If breathing and heartbeat stop, artificial respiration and heart compression should be performed immediately.

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163

5. When lightning strikes cause fires, explosions, casualties, and damage to engineering facilities, the lightning protection agency should be notified to send personnel to the site to investigate, find the cause, and take remedial measures. 6. After thunderstorm, a comprehensive inspection of engineering equipment and power lines should be carried out.

15.2.8 Flood Control Regulations 1. Try to avoid construction in areas prone to landslides, collapses and mud-rock flows. 2. Try to avoid flood periods or avoid construction in areas that may be affected by floods. When construction is necessary, drainage ditches and dams should be dug well. 3. During flood season, materials and equipment must be stored above the flood level warning line. 4. Construction machinery and electrical equipment should have rain and flood protection facilities. 5. In construction site, roads on should be kept unblocked, drainage system should be good, and site appearance should be clean and tidy. 6. All materials should be placed neatly and securely, without affecting the drainage of fire-fighting equipment, public facilities and their own projects.

15.2.9 Winter Protection Regulations 1. During construction in cold seasons, the premises must be tightly enclosed and equipped with heating facilities. 2. Main water supply pipeline must be wrapped and buried with insulation materials. In addition to temporary pipeline, water drain valve must be installed in lowlying place. When water supply is stopped, the accumulated water in pipe must be drained. 3. Timely remove ice and snow inside and outside construction site and anti-skid measures should be taken around the site. 4. When diesel engine, water pump and other equipment are temporarily out of service, the accumulated water must be drained to prevent freezing and cracking of machine.

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15.2.10 Safety Regulations During Construction 1. If pipe jacking machine comes into contact with buried pipelines, such as highvoltage cables or natural gas pipes, it may cause casualties. 2. If pipe jacking machine comes into contact with buried pipelines, such as telephone lines, fiber optic cables, water pipes or sewers, it may cause property damage and bear heavy responsibility. 3. In case of increase in rotation resistance of pipe jacking machine or abnormal noise during jacking, pipe jacking machine should be shut down for inspection in time. When it is running, no disassembly or repair is allowed. 4. Performance of various instruments should be intact and able to timely and accurately reflect abnormal conditions that may occur in head of pipe jacking machine or pipeline. 5. When pipe jacking passes through foundations such as roads, bridges and buildings, it should be realized that earth pressure or slurry pressure at head of pipe jacking machine may cause building uplift or settlement. 6. In case of possible accidental impact, necessary precautions should be taken to protect personnel safety. 7. Before construction, locations of all underground utilities have been determined and accurately marked. 8. When working in pipeline, harmful gas tester should be equipped and ventilation equipment should be installed.

15.3 Management for Environment Protection 15.3.1 The hydrogeology, vegetation, landform, climatic characteristics, human environment, cultural and historical sites around the construction site shall be investigated. The environmental management methods of relevant local departments, the division standards of environmental function zones and the pollutant discharge standards shall be understood, and corresponding measures shall be taken. 15.3.2 Attention should be paid to the protection and effective use of land resources, and the existing roads should be used as much as possible. Road construction should not block and fill drainage channels and should avoid or reduce the occupation of cultivated land, farmland, forest belts, etc. After construction, the occupied farmland, cultivated land and vegetation shall be restored. 15.3.3 Attention should be paid to the treatment of the three wastes on site. waste liquid pool should be built at low place on construction site, and the waste liquid from machinery in construction site, the waste liquid from circulation system, the domestic wastewater and the eliminated mud will flow into the waste liquid pool through diversion ditch (gradient not less than 3%). The waste water should be discharged into municipal drainage pipe network after sedimentation and filtration

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165

to reach the requirements of standards, and the waste liquid that cannot be discharged should be solidified and treated. 15.3.4 The land contaminated by muck, mud, oil, etc. should be properly replaced or restored. 15.3.5 Equipment should be installed firmly to reduce noise. When noise’s equivalent sound level exceeds 70 dBA, noise reduction measures must be taken. 15.3.6 Ecological environment should be protected, green vegetation should not be destroyed, and wild animals should not be hunted. 15.3.7 The waste soil, muck and waste mud generated during construction should be centralized stacking and transported out in time. The transport vehicle should be a sealed vehicle or a covered dump truck. The vehicle and tires should be kept clean and free from mud and other debris to prevent road pollution. 15.3.8 Flushing facilities, sewage tanks and drainage ditches should be set up at the entrance and exit of construction site, special personnel should be assigned to clean the vehicles on site. 15.3.9 Noise should be strictly controlled in accordance with “Emission standard of environment noise for boundary of construction site” (GB 12523-2011). 15.3.10 Relevant procedures should be completed for construction in night and measures should be taken to reduce the impact of sound and light. 15.3.11 A drainage system should be set up at construction site and it is strictly forbidden to discharge mud into municipal drainage system.

Chapter 16

Production Management

16.1 General Provisions 16.1.1 Before construction, units in charge of design and construction should jointly compile the “Pipe Jacking Construction Organization Design”. 16.1.2 It is necessary to carefully organize the implementation and management in accordance with the requirements of engineering construction organization and design.

16.2 The Acceptance System for Equipment Installation 16.2.1 After pipe jacking equipment is installed, its quality shall be accepted item by item by acceptance team composed of personnel from measurement, safety technology, machinery, installation, and supervision. Pipe jacking can only be started after passing the acceptance. 16.2.2 If the installation quality does not meet requirements, pipe jacking shall not be started, and a special person shall be designated to be responsible for rework.

16.3 Post Responsibility System 16.3.1 The post setting is determined by unit in charge of construction according to project scale and equipment.

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16.3.2 At least following positions shall be established: pipe jacking operator, worker above pit, worker under pit, electrician, surveying worker, etc. The construction personnel shall pass necessary safety training and operation training.

16.4 Completion Inspection and Acceptance System 16.4.1 After pipe jacking is completed, a quality acceptance committee or group shall be formed by the owner, design, supervision and construction departments to timely evaluate and accept the project quality. 16.4.2 The basis of engineering quality acceptance criteria is pipeline design or contract indicators. 16.4.3 “Project Quality Acceptance Report” shall be filled in during acceptance.

Chapter 17

Technical Files

17.1 Original Record The original record of pipe jacking should include the following: 1. 2. 3. 4. 5.

Pipe jacking construction site survey form; Back installation acceptance record; Acceptance record of guide rail installation in foundation pit; Pipe jacking construction site record sheet; Pipe jacking construction measurement record sheet.

17.2 Reporting Documents The documents reported for pipe jacking shall include the following: 1. 2. 3. 4.

Original record of pipe jacking construction; Grouting inspection record; Process (sub-item) quality assessment form; Settlement observation record.

17.3 Filing Requirements The original record of pipe jacking and the filing of reporting documents shall meet the following requirements: 1. Objective, true, accurate and complete; 2. Reflect professional characteristics, use professional terms and standard words strictly; 3. The font is neat and easy to recognize; 4. Keep pages clean and free from dirt, sewage or engine oil; © China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8_17

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5. Sentences are fluent, accurate, and focused; 6. Use international units or agreed units; 7. Original records should be completed synchronously during construction, and no supplementary or post-recording is allowed; 8. When a major event occurs, a complete record must be made, including the cause, process, development, treatment methods, results, etc.

Appendix

The Reference Table for Pipe Jacking Archives

See Tables A.1, A.2, A.3, A.4, A.5, A.6, A.7, A.8 and A.9.

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Length Estimate the total jacking force

Entry measures

Pipe diameter

Overburden thickness

Exit measures

Type, location, clear distance (on-site explanation)

Displacement requirements

Entering and exiting

Disadvantages

Underground pipeline

Settlement requirements

Obstacles to traverse

Disadvantages

Guardrail

Ladder

Water elevation

Qualified Unqualified

Compactness

Moisture content

Width Qualified Unqualified

Bearing capacity

Compressibility

Number of relay rooms

Slope

Tilt requirements

Logo

Depth

Depth of water level

Φ

Soil description

Liquid limit

Jacking section

C

Pipe bottom soil Plastic limit

Length

Support form

Groundwater type

Crossing layer

Pipe top soil

Pipe jacking

Environment

Starting Jacking pit

Soil

Project name

Table A.1 Pipe jacking construction site survey form

(continued)

Qualified Unqualified

172 Appendix: The Reference Table for Pipe Jacking Archives

Foreman:

Other

Date:

Main construction personnel

Project name

Table A.1 (continued)

Shift

Surveyor

Grouting worker

Operator

Operator

Foreman

Name

Pipe grade

Pipe section material

Post

Estimated jacking speed

Jacking method

Age

_m/day

Remark

Joint form

Single pipe section length

Jacking section

Appendix: The Reference Table for Pipe Jacking Archives 173

Second retest

First measurement

Design value (mm)

Deviation (mm)

Measured (mm)

Acceptance conclusion:

Deviation (mm)

Measured (mm) Date:

–

>2m

d

0.1%H c

0.1%L a

Allowable deviation

Measurement content b

Verticality

Jacking section Horizontal twist

Project name

Project

Table A.2 Acceptance record for back installation

e

–

(continued)

>2m

l

174 Appendix: The Reference Table for Pipe Jacking Archives

Foreman:

Observe

Third retest

Solid No deformation No cracks

Back wall

Surveyor:

Close No deformation No settlement No cracks

Back soil

Other

Straight Solid Not deformed Can withstand the maximum force Steel back fixed and stable

Date:

Date:

Apparent

Acceptance conclusion:

Deviation (mm)

Measured (mm)

Acceptance conclusion:

Operator:

Table A.2 (continued)

Conclusion:

Appendix: The Reference Table for Pipe Jacking Archives 175

Conclusion

Deviation (mm)

Measured (mm)

Conclusion

Deviation (mm)

After pipe jacking machine Measured (mm) in place

Second

First

Design value (mm)

Measured (mm)

H

Date:

Date:

a

≤ 3 mm b

Measurement content G

+ 10, 0 mm E

Allowable deviation F

Jacking section Midline displacement

Jacking elevation

Project name

Project

Table A.3 Acceptance record for guide rail installation in foundation pit

c

d

l

(continued)

>4m

176 Appendix: The Reference Table for Pipe Jacking Archives

Foreman:

Observe

Operator:

Re-inspection after pipe jacking machine in place

Table A.3 (continued)

Deviation (mm)

Straight Solid No deformation Can bear the weight of pipe jacking machine and pipe

Appearance

Surveyor:

Other

Stable left and right Stable back and forth, Stable up and down Strong welding, Close fit

Date:

Date:

Stable

Conclusion

Deviation (mm)

Measured (mm)

Conclusion

Conclusion:

Appendix: The Reference Table for Pipe Jacking Archives 177

Time

Shift record

Handover time

Date

Project name

Class progress

Soil

Footage

Jacking section

Number of jacking picks

Number two

Jacking force

Inclinometer reading

Pipe material

jacking force

Target coordinates

Elevation deviation

Remark

Successor

Grouting state

Total jacking distance

Handover person

Light target coordinates

Horizontal deviation

Number Jacking Number of jacking force Pitch Deflection three picks (MPa)

Soil chamber pressure MPa Number one

Number of offmanagers in this class

Number of pipes jacked

Table A.4 Pipe jacking site record

178 Appendix: The Reference Table for Pipe Jacking Archives

Appendix: The Reference Table for Pipe Jacking Archives

179

Table A.5 Pipe jacking survey record Jacking section

Project name Serial number

Number of pipes jacked

Jacking distance

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 Surveyor:

Date of measurement:

Midline deviation (mm)

Elevation deviation (mm)

Left

High

Right

Low

Remark

180

Appendix: The Reference Table for Pipe Jacking Archives

Table A.6 Pipe jacking construction record Serial number

Pipe jacking construction record Project name Construction unit Location (station number) Specifications of Pipe jacking equipment

Pipe material

Takeover form

Soil

Date (month/day)

Shift

Jacking thrust

Footage (m)

Cumulative footage (m)

kN

Centerline displacement deviation (mm) Left

Technical director

Pipe diameter

Right

Quality inspector This form shall be filled in and kept by the construction unit

Jacking measures

Hydrological situation Elevation Stagger Stagger deviation distance distanc of pipe of adjacent e of top pipe pipes bottom (mm) (mm) (mm) (+) (-)

Measuring person

The accident and measures taken

Appendix: The Reference Table for Pipe Jacking Archives

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Table A.7 Grouting inspection record Grouting inspection record

Serial number

Project name Construction unit Grouting material Grouting position (pipe number)

Grouting date

Grouting pressure (MPa)

Grouting equipment model The amount of injected Fullness material (kg)

Remark

Other instructions: Construction (supervision) unit

Construction unit Technical director

Quality inspector

Recorder

This form shall be filled in by construction unit and kept by supervision unit and construction unit

Receiving team Quality inspector

Person in charge of construction

Date of assessment

Rating

%

Number of points to be measured

Average pass rate

Allowable Deviation value or actual measurement value at actual measurement deviation point Measurement (specified value ± items deviation value) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 mm

Number of main projects

Stake Quality situation

Process (sub-item) name

Serial number

Part (segment) name

Party team

Serial number

Serial Visual inspection number items

Construction unit

Project name

Process (sub-item) quality assessment table

Table A.8 Process (sub-item) quality assessment table

Qualified points

Pass rate %

Evaluation Opinion

182 Appendix: The Reference Table for Pipe Jacking Archives

Appendix: The Reference Table for Pipe Jacking Archives

183

Table A.9 Settlement observation record Settlement observation record

Serial number

Project name Construction unit Benchmark number

Instrument model

Benchmark position

Instrument verification date

Benchmark elevation

Pipe jacking machine location

Observation date

Temperature Observations

Observation point

First (m)

Times

Times

Last cumulative

This settlement

Total settlement

settlement (mm)

(mm)

(mm)

Observation point layout diagram:

Technical director

Reviewer

Calculator

Surveyor

Observation Unit Seal

This form shall be kept by surveying unit, urban construction archives, supervision unit and construction unit

References

1. “Code for construction and acceptance of water and sewerage pipeline works” GB 50268-2008. 2. “Technical specification for pipe jacking of water supply and sewerage engineering” CECS 246-2008. 3. “Construction regulations for pipe jacking engineering” DG/TJ 08-2049-2008. 4. “Reinforced concrete sewer pipes used for jacking construction” JC/T 640-2010. 5. “Concrete and reinforced concrete sewer pipes” GB 11836-2009. 6. “Prestressed concrete cylinder pipe” GB/T 19685-2005. 7. “Glass fiber reinforced plastics jacking pipe” GB/T 21492-2008. 8. “Glass fiber reinforced plastics mortar pipes” GB/T 21238-2007. 9. “Technical specification for building foundation pit support” DB 11/489-2007. 10. “Technical specification for building foundation pit support” JGJ 120-2012. 11. “Blasting Safety Regulations” GB 6722-2014. 12. “Technical specification for Construction machinery safety in use” JGJ 33-2012. 13. “Safety Technical Regulations for the Management, Use, Inspection and Maintenance of Handheld Power Tools” GB/T 3787-2006. 14. “Technical specification for construction site temporary electrical safety” JGJ 46-2005. 15. Zhiguo Wu, Mechanical pipe jacking deviation correction method, Municipal technology, 2013, 31(3):114–116. 16. Binquan Yu, Chuancan Chen, Technology of pipe jacking construction, Beijing: People’s Communication Press, 1998. 17. Xuewei Wu. Construction technology and application of fixed length winding FRP sand pipe jacking, Beijing: Science Press, 2007. 18. Chunhui Ge. Pipe jacking engineering design and construction, Beijing: China Building Industry Press, 2012. 19. Pipe jacking construction technology and acceptance specifications (trial), Beijing: People’s Transport Press, 2007. 20. Xuanjiang Han. Principle and application of large-scale underground pipe jacking construction technology, Beijing: China Building Industry Press, 2008.

© China Architecture Publishing & Media Co., Ltd. 2024 L. Wang et al., Technology Standard of Pipe Jacking, https://doi.org/10.1007/978-981-99-5597-8

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