Tunnel boring machines: trends in design & construction of mechanized tunnelling: proceedings of the International Lecture Series in TBM Tunnelling Trends, Hagenberg, Austria, 14-15 December, 1995 9781003078081, 1003078087

Citation preview

TUNNEL BORING MACHINES

PROCEEDINGS OF THE INTERNATIONAL LECTURE SERIES TBM TUNNELLING TRENDS HAGENBERGI AUSTRIA I 14-15 DECEMBER 1995

Tunnel Boring Machines

Trends in Design & Construction of Mechanized Tunnelling Edited by

HARALD WAGNER & ALFRED SCHULTER D2 Consult, Linz, Austria

r.?\ Taylor & Francis ~ Taylor & Francis Group

LONDON AND NEW YORK

The texts of the various papers in this volume were set individually by typists under the supervision of either each of the authors concerned or the editor.

Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Taylor & Frands, Rotterdam, provided that the base fee of US$1.50 per copy, plus US$O.I 0 per page is paid directly to Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, USA. For those organizations that have been granted a photocopy license by CCC, a separate system of payment has been arranged. The fee code for users of the Transactional Reporting Service is: 905410811 8/96 US$I.50 + US$O.I o. Published by Taylor & Frands 2 Park Square, Milton Park, Abingdon, axon, OX14 4RN 52 Vanderbilt Avenue, New York, NY 10017 Transferred to Digital Printing 2006 ISBN 90 5410 8118 © 1996 Taylor & Frands

Publisher's Note The publisher has gone to great lengths to ensure the quality of this reprint but points out that some imperfections in the original may be apparent

CONFERENCE SPONSORED BY Government of Upper Austria, Linz

Federal Ministry of Economics, Vienna

International Tunnelling Association (ITA), France

American Society of Civil Engineering (ASCE), USA

CONFERENCE COORDINATED BY

...

**** * * * * ** **

'."

Central Austrian Training in Technologies Relay Centre Austria of the EU

Regio nal Office Linz

HARALD WAGNER

Civil Engineer, born in 1941, Graduated from Technical University of Graz (M.Se. 1970). Geotechnological Education at Soil mechanic Laboratory Hamburg, Germany (1972). Theodor-Kbrner - Award for Science, Vienna and Graduation for Doctor Technical Science (Ph.D.) at Technical University of Graz, Austria (1974). Licensed Professional Engineer of Austria (P.E., 1980). Authorized manager for Engineering and Technology of Tunnelling Contractor Beton- und Monierbau - Innsbruck (1984). Partner and Managing Director of D2 Consult Ine., Engineering and Consulting Company for Tunnelling and Geotechnology with emphasiS on innovative developments, based in Linz, Austria and Rockville, Maryland / USA (1985). Founder and Board Member of Geomechatronic Center Linz (GCL) in Softwarepark Hagenberg, a non-profit organization, composed of Research Institutes from Universities and Tunnelling Industry, to serve the Tunnelling Community with better concepts (1992). Promoter for Tunnelling Technology of new, synergetic concept, combining the geomechanic philosophy of the New Austrian Tunnelling Method (NATM) with cyclic - incremental construction elements and parallel continuous operations of Tunnel-Boring-Machine (TBM) Technology and precast reinforced concrete Tunnel Lining Segments.

ALFRED SCHULTER Civil Engineer, born in 1949. Graduated from Technical High School of Graz (B.Se., 1968), and from Technical University of Graz (M.Sc., 1976). Collaboration with Harald Wagner since 1977 in Tunnel Design and Preparation Activities in NATM and Shield Driven Tunnelling Technology for Contractor Beton- und Monierbau, Innsbruck (1980). Licensed Professional Engineer of Austria (P.E., 1985). Experiences as acting Site- and Project Manager of Tunnel Projects on behalf of several Construction Joint Ventures in Austria, Germany and Greece (1986). Graduation for Doctor of Technical Science (PhD.) at Technical University of Graz (1993). Partner and Managing Director of D2 Consult Inc. Developed numerous innovative concepts several of which have been international patented in Subway, Railway, Highway and Water Tunnel projects throughout Europe, USA and Asia. Active in international publishing of scientific papers.

VII

ORGANIZATION

HONORARY CHAIRMAN

Sebastiano Pelizza Prof. Dr. Ing.

ITA - International Tunnelling Association, Bron Cedex, France Polytechnical University of Turin, Italy

EXECUTIVE CHAIRMAN

Harald Wagner Dipl.-Ing. Dr.techn.

D2 Consult Ltd., Linz, Austria GCL - Geomechatronic Center Linz, Austria

SESSION CHAIRMEN

Pascal Guedon Ing.

Simecsol Ltd. , Le Plessis Robinson, France

Peter Kogler Dipl.-Ing.

Alpine Westfalia Ltd., Zeltweg, Austria

Rick P. Lovat Ing.

Lovat Tunnel Equipment Inc. , Etobicoke, Canada

Harald uuffer Dipl.-Ing. Dr.

Porr AG, Vienna, Austria

ORGANIZERS D2 CONSULT LTD., LINZ GCL-GEOMECHATRONlC CENTER LINZ

SCIENTIFIC COMMITTEE

Bruno Buchberger Prof. DDr.

RISC - Research Institute for Symbolic Computation, Kepler University Linz, Austria

Gunther Swoboda Prof. Dr. Ing.

GCL Geomechatronic Center Linz, Austria Technical University Innsbruck, Austria

Alfred Schulter Dipl.-Ing. Dr. techn.

D2 Consult Ltd., Linz, Austria

Manish D. Kothari M. Se.

ASCE, American Society of Civil Engineers D2 Consult Ltd. , Rockville, USA

IX

CONFERENCE SECRETARY

Andreas Beil Dipl.-Ing.

D2 Consult Ltd. , Linz, Austria

Christa Fried! cand. Mag.

Assistant Conference secretary

TECHNICAL SECRETARIAT

Hubert Maier Ing.

D2 Consult Ltd., Linz, Austria

HorstWoger Ing.

D2 Consult Ltd., Linz, Austria

CONFERENCE ADMINISTRATION

Carolin Strohhausl-Stross DDipl.-Ing.

D2 Consult Ltd., Linz, Austria

Margarete Prend!

D2 Consult Ltd., Linz, Austria

Ursula Steingruber

D2 Consult Ltd., Linz, Austria

Regina Brandstiitter

GCL - Geomechatronic Center Linz, Austria

ASSISTANCE AT THE ORGANIZATION:

Adolf R. Hemedinger

Hemedinger Public Relations, Linz, Austria

Doris Hemedinger

Dr.

Alfred Wolf

Grafik Design, Linz, Austria

x

Attendees of the conference at the court yard of SchlojS Hagenberg

AIGNER Peter, ARISTAGHES Pierre, AUTUORI Philippe, BABENDERERDE Lars, BABENDERERDE Siegmund, BARGMANN Paul, BAZ Mahmoud, BElL Andreas, BIBES Jean-Paul, BIELECKI Rolf, BLINDOW Friedrich, BOULANGER Jean Louis, BOUSSOULAS Nikos, BOUYGUES Olivier, BRANDSTETTER Regina , BRAUN Willi, BROCKWAY Jack, BROSCH Franz-Josef, BUCHBERGER Bruno, BURGER Werner, CELADA Benjamin, CERESOLA Aldo, CHOMA Stefan, CUFER Suzana, DALLERJosef, DELlS Theodore, DESREUMAUX Stephane, DIENER Andreas, DINGA Peter, DOPPER Hans, EBERLEIN Herbert, EINSTEIN Herbert, EKREM Osman, ENZENHOFER Wilfried, ERDEM Yucel, ERTEN Atila, ERTEN Hakan, ERTL Jan, FERRARI Robert, FRANKOVSKY Miloslav, FRIEDL Christa, FUCHSBERGER Martin, GARGIULO Sabato, GEHRING Kari Heinz, GHAREHKHANI Ali, GLANG Siegfried, GOBL Peter, GOLD Heimo, GOLSER Johann, GRABE We rner, GRADENEGGER He lmut, GUEDES DE MELO Pedro, GUEDON Pascal, GUNARATNAM Daniel, HAACK Alfred, HANAMURA Tetsuya, HASER Felix, HElLEGGER Rudolf, HElM Norbert, HERWEGH Marco, HERWEGH Norbert, HINTERPLATTNER Bernhard, HLADIK Ivo HUTTER Stefan, ISLER ]lirg, lAGER Manfre d , JANOSKE Boris, JANZON Hans, JODL Hans Georg, KAIPHAS Albert, KASPAREK Ulryk, KAUER Georg, KIENREICH Rainer, KLEPSATEL Frantisek, KLOSE Christian, KNABE Michael , KOGLER Peter, KONTOPIDOU Evdoxia, KOSC Anton, KOUKOUTAS Stelios, KRCIK Marian, KREUZER Ernst, KRIEGL Gunter, LANGWIESER Josef, LAUFFER Harald, LAZZARINO Maurizio, LEBERBAUER Peter, LEE Cheng­ An, LEITL Christoph, LETTNER Gerald, LIN Sho u-I, LlNDTNER Wolfgang, LlNIGER Wolfgang, LOVAT Rick, MAlER Hubert, MANSOUR Mona , MARIK Libo r, MARTAK Lothar, MESANOVIC Damir, MOSLER Jiri, MOYSON Dirk, MUELLER Siegfried, PANAGOPOULOS George, PAPACHLIMINTZOS Panagiotis, PELlZZA Sebastiano, PETERSDORFF Albrecht, PICKLJosef, PRAZAK Milan, PRENDL Margarete, QUONIAM Alain, RACLAVSKY Jaroslav, RATKOVSKY Jr., RATKOVSKY Koloman, REA Giovanni, REDER Klaus, REMMER Franz, SADGORSKI Wellin, SAMETZ Ludwig , SCHMIDT Harald, SCHONWALDER Markus, SCHREYER Jorg, SCHULTER Alfred, SIFFERLINGER Nikolaus, SIMONSEN Knut Ivar, SNUPAREK Richard, SOVCIK Stefan, SRB Martin , STAMOS Costas, STEHLIK Ermin, STEINGRUBER Ursula, STEMPKOWSKl Rainer, STERNATH Rupert, STIFTER Sabine, STIX Gerhard, STROHHAUSL­ STROSS Carolin, STROHHAUSL Siegfried, SUKPRAPRUTI Buncha, SUKPRAPRUTI Buntoon , SWOBODA Gunte r, TENNE Ola, TESAR Jiri , TROJER Karl , VAFIDOU Katerina, VIGL Alois, WACHTER Robert , WAGNER Harald, WALLIS Shani, WENNMOHS Karl-Heinz, WINTER Peter, WOGER Horst, WOLETZ Daniela, WOLFF Wilfried, YANG Quiang, YOU Kwangho, ZEMAN Vladimir, ZENKER Edmund

XI

TABLE OF CONTENTS B. Buchberger Welcome address

1

C. Leid Welcome address of the Government of Upper Austria

3

BLOCK A • TBM DRIVE· TECHNOLOGY

H. Wagner TBM tunnelling based on Geomechatronic Key note lecture

7

H. Einstein Decisions aids for tunnelling

13

G. Swoboda / M. Mansour Three-Dimensional numerical modelling of slurry shield tunnelling

27

K.H. Gehring Design Criteria for TBM's with respect to real rock pressure

43

M. Herrenknecht Latest developments in mechanised tunnelling technology

55

S. Strohhausl TBM tunnelling under high overburden with yielding segmental linings (Eureka Project EU 1079 - "Contun")

61

H. G. Jodl / R. Stempkowski Operations research aspects of TBM drives - Case study of Wienerwald-Tunnel

69

BLOCK B • TBM AUTOMATION, SIMULATION AND QUALITY CONTROL

S. Stifter Chances for cooperation between industry and university ­ Synergies for TBM tunnelling

83

A. Schulter The importance of geometry for computer controlled segment erection

89

R. Bielecki / J. Schreyer Suitability test for the segmental lining for the Elbetunnel 4th tube, Hamburg

99

XIII

w. Sadgorski

European geotechnical engineering norm ENV 1997-1 and ist meaning for tunnelling

107

H. Erten / G. Kriegl TBM-Simulator - Interface model between machinery and lining

115

DINNER SPEECH

S.Pelizza Dinner Banquet at SchloiS Weinberg

123

BLOCK C - IBM CHALLENGES

S. Babendererde / L. Babendererde Experiences in mechanized tunnelling

127

o. Bouygues Geotechnical investigation during TBM drive at EOLE-Project, Paris

139

D. Gunaratnam Technology for tunnel construction with special applications for Wanjiazhai Water Transfer Project

147

H.A.Janzon High speed tunnelling in Sydney's Blue Mountains

153

R. Sternath

Construction of the railway tunnel under the Great Belt - Risk and chances

161

A. Haack Comparison between conventional tunnel driving method and TBM drives. Worldwide demand of tunnel constructions

179

J. Golser Case study of an alpine transit freight tunnel concept. Influences of geology on tunnel technology

191

T. Hanamura State of the art of the Japanese TBM technology. New developments

199

XIV

BLOCK D - TBM TUNNEL LINING / SEGMENT MANUFACTURING

R. Heilegger / A. Beil Full automated tunnel segment production system. A case study

215

W.Uniger Quality control on computer controlled tunnel segment manufacturing plant

223

N. Herwegh Requirements for sealing gaskets in yielding joints of TBM tunnelling

231

W.Grabe Design of gasktes for deformable tunnel lining joint configuration. New developments

239

E. Zenker

Joint connectors for tunnell linings

243

D.Moyson

Precast tunnel segment reinforced with steel wire fibre reinforced concrete (SFRC) - Astate of the art

247

CLOSING LECTURE

H. Wagner ClOSing lecture

257

Author Index

263

xv

WELCOME ADDRESS

B. Buchberger 1

Since our ftrst contacts with the 02 Consult company ten years ago, our institute became interested and, with the growing intensity of our cooperation, fascinated by the new technologies in tunnel construction. Our own background is computer mathematics and software, in particular "symbolic me­ thods" and part of our research is quite abstract. I remember that, at the beginning, it took me some effort to convince my young co-workers to engage in mathernatics­ based design and implementation of software for simulation and control of tunnel planning and tunnel construction. Meanwhile we went through a couple of quite successful projects in this area in a long-lasting and fulfilling cooperation with 02 Consult. Some of the researchers at our institute became deeply involved in the challenging mathe­ matical and software-technological problems of tunnel engineering. I also felt quite happy when, following an inspiration which we had at a cool beer after a nice lunch, the chairmen of 02 Consult, Dr. H. Wagner and Dr. A. Schulter, decided to build up the "Geomechatronic Consortium" and to settle this institution in the frame of our "Software Park" in Hagenberg. Under the chairmanship of Prof.Or. G. Svoboda, the Geomechatronic Consortium brought together various Au­ strian companies and institutions with expertise in all areas of tunnel engineering induding the aspects of automation and software. The consortium was able to produce considerable momentum in a technology, which has a particularly active tradition in a country like Austria. Now, today, we have the pleasure to host 1

the International Conference "Tunnelling Trends" in Hagenberg. This is surely a further important impulse for our growing Consortium and its research and develop­ ment activities and I would like to thank all participants for having followed the invitation of the organizers. I would be particularly happy, if you found also some time during the conference for a short visit of the various institutions here in the Software Park Hagenberg and I do hope that some new cooperations and projects will evolve from your being together at this place. Tunnel engineering seems to become one of the most important technologies for the future. Tunnel technologies will be able to make a signiftcant contribution to solVing pressing problems of mankind as, for example, the destructive effects of growing traffic, the dramatic growth of urbanized areas, and the urge for save storage of hazardous material. Tunnel engineering also seems to have one of the highest economic growth potentials. Ten years age, in my vision I have seen this institute, when the castle still has been a ruin, and the people though, that this vision is a joke. Today I have an other vision and you should feel free to think it is another joke, and in this vision I see the next conference to take place ftve years from now, in the underground of Hagenberg. I wish that this conference, by the talks, the discussions, and the personal contacts between experts, will create ideas for further technological improvements, and increase in the level of automation, new applications and new business chances.

ProfDrDr.h.c., Chairman of the Research Institute for Symbolic Computation, Hagenberg, Austria 1

WELCOME ADDRESS OF THE GOVERNMENT OF UPPER AUSTRIA C. Leitl 1

On behalf of the Government of Upper Austria I would like to welcome the honourable Attendees of the TBM Tunnelling Trends Conference here in Hagenberg, the beautiful village of Upper Austria surrounded by the scenic Muhlviertel. My special welcome is addressed to Prof. Sebastiano Pelizza, President of the International Tunnelling Association, co-sponsoring this conference, and to prof. Bruno Buchberger, heading the Research Institute for Symbolic Computation, in short RISC, who is hosting this conference. I also have the pleasure to mention, that the American Society for Civil Engineers in New York is co­ sponsoring this conference and represented by Prof. Herbert Einstein from Massachusetts Institute of Technology and Mr. Manish Kothari. In addition I would like to mention the members of the organizing institutions with Prof. Gunter Swoboda from the Geomechatronic Center Linz and the team of D2 Consult, Dr. Wagner and Dr. Schulter, Linz.

technology. I quickly became familiar and fascinated by the presented concept, which did combine most advanced information technology with sophisticated mechanical and electronical equipment. The government of Upper Austria continuously has supported and still supports the development of advanced technologies in the underground construction industry, especially when combined with Universities like in the case of Geomechatronic Center Linz. With this policy in science and technology, Upper Austria has achieved one of the lowest unemployment rates in the Alpine-Adriatic region. Our world is getting closer with increasing world population, and global networking is becoming even more decisive for the quality and stability of our life. Infrastructures like tunnels, are guararIteeing our present living standard and the living standard in developing countries. Worldwide competition is featuring free markets and forcing the ingenuity of our engineers. To the best of my knowledge, visions for the underground industry, born in Linz and here in Hagenberg, have proven their compatibility with other countries underground construction traditions. We are proud also to mention, that from a number of countries, e.g. the United States, Italy, France and Germany, the technology of "Linzer-Tunnelbau-Methode" with precast concrete segmental linings for tunnels has been successfully applied. And the

Approximately only five years ago, I as a member of the Government of Upper Austria have been approached to support the idea for establishing an institution, dedicated to the Geomechatronic idea. This idea has been reinforced by impressing facts and figures in regard to the international development of underground structures. I have been born into the construction industry, and having been grown up with the rapid development of 1

Dr., Government of Upper Austria

3

technology as such could contribute to the improvement of quality of life and to the employment of the construction industry both at home and in those countries. The beginning has been giving hope and this conference is a clear indication for the optimism which became a key element for the work in the past. I want to draw your attention to the dinner banquet at SchloB Weinberg, hoping that you will fmd this a pleasant relieve from intensive conference activity. The government of Upper Austria wishes the esteemed attendees at this international lecture series a very successful venue.

4

BLOCK A TBM DRIVE· TECHNOLOGY

TBM TUNNELLING BASED ON GEOMECHATRONIC Keynote Lecture H. Wagner

ABSTRACT

and robotic systems is ringing. In accor­ dance with the complex nature of the network consisting of mechanical and civil engineering, civil engineers and especially geotechnical engineers are challenged to develop innovative solutions. Geomecha­ tronics will help to track along this route of interfusion successfully between civil engineers and mechanical engineers, bet­ ween lining and rock and between indivi­ dual lining segments.

In civil engineering, tunnel construction has always been based on observations far more than any other construction. Reason for this phenomenon can be seen in the fact, that there is no other condition as decisive as the changing ground condi­ tions in underground construction. Obser­ vational methods by their nature are subject of experience, especially when using pre­ dominantly manual methods for construc­ tion. Experience can be explained as kind of data base of an individual. With the development of information technology it became feasible for almost everybody to collect data, and to work on data base. In addition to this, mechanization started to become an increasing part of underground construction. It was only a question of time when the marriage between informa­ tion technology and mechanization was to be celebrated.

INTRODUCING GEOMECHATRONICS In recent years one of the leading European

car manufacturers has expressed the wil­ lingness, to employ all of the graduates of the mechatronic faculty of Linz University. This shows the excellent reputation which this faculty could gain in the past. Inspired by this success, and oriented at the same industrial needs, an institute has been created in association with the Universities of Linz and Innsbruck and in close coope­ ration with the Industry, dedicated to the mechatronic idea. This institute has been named Geomechatronic Center Linz, (GCL). The market of underground engineering and construction is growing and to some extent related to the growth of world population. There are developments of people escaping from the country side to the urban areas mostly in the coastal regi­ ons, creating transportation needs. Solutions can only be found by going underground using concepts and systems on a compe­

Parallel hereto, tunnelling became more and more subject of engineering and thus also subject of design. The designers started to develop models, and to develop simu­ lations to model nature in their design office, and to prepare documents for pro­ jects on competitive basis. This was the time, when Geomechatronics became the logic consequence of mechanization and the capability, to combine mechanization with information technology. With steadily increasing requirements in regard to quality, safety and economy, the bell of automation 1

1

Dipl.-Ing. Dr. techn., D2 Consult Linz, Austria

7

titive basis. With geomechatronics in TBM­ tunnelling, the potential of improvements in regard to cost and quality has a real chance to grow. Geomechatronic is using the diSciplines of mechanics, electronics and robotics in the field of geotechnology. Geotechnology means all geotechnic technologies induding especially TBM-technology. By the nature of this new discipline, there are stronger roots and relations in mechanized tunnel­ ling, especially when entering into full face tunnel boring concepts with precast con­ crete segmental Jinings, than in conventional tunnelling with incremental support. Howe­ ver, in spite of some differences in the lining concept, conventional tunnelling is considered to be included in geomecha­ tronics as well. The basics of the geome­ chanical understanding of the interaction between excavation and geomechanical response are considered to be identical, as it all depends on the ground. Geomechatronic thus acts as a connecting member between geotechnology and me­ chatronics. It has to be based on structural assumptions allowing for the development of advanced mechatronic approach. Struc­ tural details and even construction proce­ dures have to be developed in order to be compatible with the mechatronic ap­ proach. The use of standard features even if mixed with one or the other mechatro­ nical suitable detail, e.g. of the lining joints, may end up in results, which do not signi­ ficant differ from standard solutions.

engineers and engineering can be achieved without any engineering training or any other technical education. Design has to be understood in context with engineering, also when applying geomechatronics. Design is creating some­ thing, which has not existed before. Design is essential to engineering, and is virtually synonymous for any technical development. Structural design is most commonly asso­ ciated with mechanical and civil engineering and with the SUitability for automation. The concept of failure in mechanical and structural engineering is essential of all engineering understanding including the geomechatronic approach. Engineering design has its first and for most objective in failure observation and subsequently prevention. Disasters that do occur are ultimately failures either of design or con­ struction. The lessons learned from disasters can do more to advance engineering know­ ledge than all successful machines and structures in the world together. Failures appear to be inevitable in the wake of prolonged success, which encou­ rages lower margins of safety. Failures in turn lead to greater safety margins and new periods of success . To understand what engineering is, and what engineers do , is to understand how failures can happen, and how they can contribute more than successes to advance the underground technology. With this understanding in the future, less cases will be created and the mutual understanding of all parties involved in underground construction will be im­ proved to the benefit of our industry and of global society.

ENGINEERING AND DESIGN Engineering is in general a human endea­ vor. It is integrated into our culture and intellectual tradition. The ideas of enginee­ ring are in fact in our bones, and historically became part of our human nature. Funda­ mental understanding and appreciation of

CREATING EUREKA PROJECT Thanks to Eureka project EU 360, remar­ kable developments in tunnelling techno­ logy will make it easier and cheaper to

8

build tunnels. An Austrian-German-Italian team has come up with a way of cutting costs and time consumption in tunnelling. A robot controlled precision lining system has been developed under the aegis of the project, making it possible to excavate and line a tunnel at the same time also in soft ground using shield mould. Non stop tunnelling will open the way to pierce the Alps clear from one side to the other, or make a tunnel between Europe and Africa.

ground. This will be achieved with seg­ ments of wedge shaped configurations.

Austrians have good cause to be interested in tunnelling. The Brenner Pass strategically located on a direct line between two of the power houses of the European econo­ my - Munich and Milan - is the obvious route for 2 mio. trucks and 20 mio. holiday makers each year. Continuous excavation will be achieved by using innovative links between tunnel lining segments. Segments have to be locked precisely one another both radially and longitudinally in a position determined mathematically and controlled by sensors. The precision approach will also minimize damage to the lining seg­ ments. The project employs sophisticated tech­ niques to optimize the design of compon­ ents: 3-D animation to plan lining installa­ tion, and finite element structural analysis to determine the stresses and strains caused during jacking. A real-time computer system will allow the site manager in his surface cabin to monitor and control the robot fitting of the rings underground. The project has developed a robotics application based on an innovative com­ bination of principles for tunnel lining segments. The kinematic principle must allow segments to be locked precisely one another both radially and longitudinally in a position determined mathematically and controlled by sensors. The geometric prin­ ciple must allow simultaneous installation of the segments and excavation of the

Figure 1. Saint Clair River Railway Tunnel, Canada - Finished Structure of conventionally bolted and gasketed one-pass precast-concrete segmental lining (1994)

Conventional segmental lining methods among others use a special key stone to close each ring of segments in the roof area. Examples for this lining method can be found presently all over the world. These systems are used as one-pass lining systems, e.g. for the Saint Clair River Railway Tunnel, and for the Yan' an Dong Lu River Tunnel in Shanghai, China.

Figure 2. Yan'an Dong Lu River Highway Tunnel, Second Tube, Shanghai, China - Thrusters keeping conventional bolted and gasketed one-pass segments in place during erection (1995)

9

Other systems are related to expansion gaps arranged in the roof area and widely used in the United States, where it is known as the Los Angeles Tunnelling Method (LATM). Mostly this system is used as a primary lining, later followed by the instal­ lation of water proofing membranes in between the primary lining and the cast­ in-place final concrete lining. An example is given for this system with the TBM­ driven section of contract section E4 of the Washington Metro.

for the Wanjiazhai Yellow River Diversion Project (WYRDP) in Northern Shanxi, China.

Figure 4. Yellow River Diversion Tunnel No. 8 on General Trunk Line - Precast concrete one-pass lining segment installation. double-trapezoidal honeycomb­ type segment, with hydraulic erector and timber dowel connector in Circumferential joint (1995)

FOCUSING THE FUTURE

There are only a few reasons for the de­ velopment of geomechatronics in TBM­ tunnelling, one is cost reduction and the other one is quality improvement. Geome­ chatronics is aiming to be acknowledged as to facilitate , coordinate and integrate research for the design and construction of the underground industry. It proVides to the underground industry perspectives for future construction related research and development. Cooperative research efforts by involVing the industry, public authorities and univer­ sities have been undertaken with the target to practically approach and to improve the business performance of the underground industry. Development of innovative solutions to the underground engineering challenges are coming from collections of worldwide underground experiences. In coordinating research efforts geomechatronic helped the underground construction industry

Figure 3. Washington Metro Green Line Section E4, USA - Precast Concrete Primary Segmental Lining without any mechanical connectors in the joints ex­ panded towards the underground (1995)

Another interesting development has been used for water supply tunnels combining two trapezoidal segments on their longer side to hexagonal shaped segments, known as so called Honeycomb Segments. This type of segment, originally developed in Italy, is gaining popularity. It additionally combines the technology of continuous excavation and installation with advantages of force flow in the segments, temporary during construction and in the final con­ struction stage. Using this type of segments together with fast locking joint configura­ tions seems to offer state of the art segments for straight tunnels. Such segments have been used among others for the Evinos Project in Greece, and is under construction 10

including machine manufacturers and de­ signers to develop high performance con­ struction systems and construction proce­ dures. Geomechatronics outlines vital and viable means to develop and deploy underground construction needs for the 21st century underground infrastructure in order to remain competitive in the next decades. Geomechatronics success over its first five years promises for even greater opportu­ nities for contributions to the underground construction industry. There are no limits to the impact geomechatronics can make. The underground construction community is challenged to contribute all its experience and resources for further development of the underground world.

REFERENCES [l} Petroski, Henry. To engineer is human

- the role offailure in successful design . Vintage Books, a division ofRandom House Inc ., New York 1992 [2} EUREKA-Project EU 360 Eurotunnel.

Diggingfor victory overpolution. Published by Eureka-Secretariat, Brussels-Vienna, 1995

11

DECISION AIDS FOR TUNNELLING H. H. Einstein 1

ABSTRACT

• Decision making under uncertainty inclu­ ding risk analysis. Planners, designers and contractors have to make decisions in which they have to explicitly consider the uncertainty in cost, time and resource requirements; (Fig. la)

The Decision Aids for Tunnelling (DAT) are a computer based interactive tool with which tunnel construction cost, time and resource requirements can be estimated. It is possible to include uncertainties if desired and thus have results in form of distributions which are needed in modern decision making. The paper briefly reviews the basic structure of the DAT and then discusses applications such as cost, time and resource estimation for transalpine tunnels. Following this, and most important in the context of this lecture series, are applications of the DAT to compare diffe­ rent tunnelling technologies.

Figure la. Cost Distribution for Different Alignment Alternatives

INTRODUCTION

The Decision Aids for Tunnelling (DAn have been developed during the last five years at MIT and Ecole Polytechnique Federale based on preceding work at MIT in the area of tunnel construction modelling and representation of geologic uncertainty (e.g. Einstein et al., 1996; Einstein et al 1978). Recent applications for the Swiss Alp Transit project and other tunnels in Europe and elsewhere (e.g. Einstein et al. 1991, 1992; Descoeudres and Dudt, 1993, 1994), for the design of a continuous tunnel boring machine (Nelson et al., 1992) and for the assessment of a tube transportation system in cities (Sinfield and Einstein, 1995) indicate why the DAT are needed in plan­ ning, design and construction of under­ ground facilities: 1

• Detailed design and construction decisi­ ons. Designers and contractors have to compare a large number of different tunnel geometries, excavation procedures and other construction details; (Fig. 1b)

Figure lb. Time Distance Diagram for Different Con­ struction Procedures

Professor of Civil Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts USA

13

of uncertainty about geologic conditions or, for that matter, certain information at specific locations such as in boreholes.

• Technology assessment. Designers, con­ tractors and equipment- and material suppliers need to assess the effect of different technologies on cost, time and environmental consequences. (Fig. 1c)

• Geologic Updating This allows one to use observed geologic conditions as the tunnel is excavated to modify the geologic description of the as yet unexcavated part of the tunnel. • Tunnel Analysis and Design These modules are mainly intended for educational use. One can interactively design a tunnel cross-section and perform simple analyses of the liner stresses and displacements.

Figure 1c. Comparison of Advance Rates for different tunnel technologies

The DAT which allow one to model any geology, any construction procedure and any technology while simultaneously consi­ dering uncertainties, if desired, satisfy this requirement. This paper will, after brief description of the DAT-structure present applications of the DAT which illustrate their capabilities. Given the topic of this lecture series, emphasis will be placed on the technology assessment.

• Construction Simulation ("Construction Simulator") This module simulates the tunnel con­ struction process through the ground class profiles created by the geology module. This involves relating geologiC conditions (ground classes) to construc­ tion classes. Construction classes define tunnel cross sections, initial and perma­ nent support, as well as excavation methods which are best suited for a particular ground class. The Construction Simulator then calculates cost, time and resources (material, manpower, equip­ ment). It is also possible to simulate the construction of a system of tunnels or other underground openings which de­ pend on each other such as the construc­ tion of an access shaft from which tunnels are driven. A very important characteristic of the Construction Simulator is to include so called construction uncertainties reflecting the fact that construction performance varies even under constant geolo­ gic!geotechnical conditions and that there are unexpected and/or irregularly occurring events such as equipment failure an accidents.

STRUCTURE OF THE DAT

Only the most essential characteristics will be mentioned here since the DAT have been described in detail elsewhere (Einstein et al., 1992, Halabe, 1995). The DAT are an interactive computerized tool based on C++/ C, MOTIF and the XWINDOW system. They consist of five components (modules): • Description of Geology (Geology Module) This module transforms user input on geologic and geotechnical conditions into probabilistic geologic/ geotechnical profiles through which the construction of the tunnel(s) is simulated by the "Construction Simulator". The geolo­ gic/ geotechnical descriptions can be in any form, such as the ground classifica­ tion systems used in the NATM, or using basic physical properties. Included in this description can be the expression 14

The DAT user describes construction, including the consideration of uncer­ tainties through activity networks such as those in Figures 2a and 2b. A network represents all activities occurring in a round or cycle of tunnel construction and the Construction Simulator applies the appropriate networks(s) round after round (cycle after cycle) to "build" the tunnel. The networks appear on the

screen as shown in Figures 2a and b and the user can interactively create and modify them. • Project and Construction Management Decisions during construction such as changing from heading and bench exca­ vation to full face excavation have to be made based on estimates of the expected conditions. This module allows one to compare the consequences of different decisions on a probabilistic basis. The applications of the DAT, which will now be discussed, make use of the Geology Module and the Construction Simulator. The examples will make it possible to illustrate further details about these modules and the DAT overall.

DETERMINING CONSTRUCTION COST AND TIME

Figure 2b. Decision Aids for Tunnelling (DAY) Con­ struction Network for Drill and Blast, Heading and Benching Construction

Several extensive studies have been done with the DAT, amongst others for AlpTransit (Einstein et al., 1991, 1992; Descoeudres and Dudt, 1993, 1994), and some of the work done regarding the Gotthard Base Tunnel will be presented here. The geology was first subdivided in homogeneous zones (Figure 3) and typical geologic!geotechnical

Figure 3. Estimated Homogeneous Geologic Zones Gottbard Base Tunnel and Possible Combination ofShafts and Tunnels

15

parameters were defined and associated with ground classes (Table 1).

The geologic/ geotechnical characterization is then associated with design and con­ struction consequences. Specifically the typical support requirements as illustrated in Figure 5 can be related to construction activities and input in detailed networks and associated cost and time equations as shown in Figure 2a. In the case of the Gotthard Base Tunnel, a simpler procedure was used, in that each of the groundclasses (Table 1) was associated with costs per linear meter and advance rates (the latter corresponds to the simple network of Figure 2b). Each groundclass not only has its particular unit cost and advance rate but we also considered the construction uncertainty as illustrated in Figure 6 for the advance rate.

Table 1 Gotthard Base Tunnel Parameter State - Ground Class . Association Lltholn,! Gnllu-'Granita' Gneiu·'Granlte'

Gnel .. ·'Granlte' Cn,iu·'Grlnite' Gn 1.·'Granlte' Gnelss·IGranlte' Schist

Schist Schist Schlu Schist Schist Ph lIite Ph IIiCe Ph IIlte Ph Jllce Ph lllte Phylllle

Fa.ll i n.

not not not

faulted bulled flulled

hulled hulled hulted not not not

faulted faulted

fulle d

faulted

faulted hulted

not not not

faulled faulted faulted

halted

hulled faulud

O.,erburden dOO.

D1

1000·15DQ m >150Q In

dOOO la 1001-1500 m ::.1500

11'1

dOOO

m

1000-1500 >1!OO

m m

1500 m

Grund

W3 M3 H3

W. M. H' W3 M3 H3

m

W3 M3 H3

3 bar)

very strong waler acting on concrete single-layer KDB

not very strong water acting on concrete single-layer WUB 01" KOB (umbfella seal ot alJ.round) lwo-layer \NUB Of KOD (all-round)

single-layer \NUB with KOB 01 twI>layer KOB

single.Jayer WU8 with KOB

single or ~yer wue

(all-round)

(all-round)

(alkotnt)

with KOB (al!-round)

Remar1t.s: KOB: seal with plastic sealing membrane WUB: seal with inner shell comprising watertight concrete

Table 2. Sealing combinations based on a draft for updating the DS 853 for two-shell lining (S7VVA, PSP (1994))

For seals comprising plastic sealing mem­ branes, generally speaking, as far as the Deutsche Bahn AG is concerned the DS 853 (Deutsche Bahn AG (993)) is taken as the basis. The most important regulations are to be found there in Section 87 ff, essential sealing details in Appendix 13 "Sealing new Railway Tunnels".

CURRENT AND FUTURE CONSTRUC· TlON VOLUMES IN GERMANY

Since 1990, the total length of operational transport tunnels has grown from around 850 to almost 1,100 km. This increase has partly to do with ongoing urban rapid transit railway construction with an annual rate of completion corresponding to some 17 to 18 track km (Fig. 7, curve metro). This corresponds to a length of some 12 running km and in turn, to an increase of roughly 60 km over the observed 5 year period. On the other hand, in the field of railways (curve railway) around 150 km of highly modern tunnels have opened since 1990 in addition to the existing network, mainly in conjunction with the two new lines Hanover-Wurzburg and Mannheim-Stuttgart. Finally, approx. 15 km of additional tunnels have been opened for traffic in conjunction with federal high­ ways since 1990 (curve road). Fig. 8 shows the award-related share for the most important clients in transport tunnel construction in Germany.

Figure 6. Possible combinations for sealing systems in the case of two-shell tunnel lining depending on the soil and water conditions; Haack (Oct. 1995)

184

At the turn-of-the-year 1994/95, there were roughly 96 km of transport tunnels and approx. 75 km of supply and disposal lines with major cross-sections under construc­ tion. Table 3 provides the individual details. Related to the driven length, at least 56 %, a ration of almost 3/5 is accounted for transport tunnels and accordingly around 2/5 by supply and disposal tunnels (Fig.

9a). However, the weight of the transport tunnels becomes far more evident if the excavated volumes are included. Thus, if transport tunnels on the one hand, are compared with utility tunnels on the other, we determine that the length-related ratio is approx. 5/4 but the volume ratio around 55/4 (please see Table 3 and Fig. 9b).

Figure 7. Contracts awarded in traffic tunnel construction between 1980 and 1995

185

Figure 8. Contract-related and length-related data on use of traffic tunnels constructed between 1980 and 1995

Figure 9. Proportion of the various types of tunnel usefor the turn-of-the-year 1994/95 (values in brackets refer to the previous year).

Type Underground, urban and rapid transit systems (US) Long distance railway (B) Road (S) Utility lines M (A) Sewerage Others (So) Total

km 50 9 37 18 56 1 171

For transport tunnel construction, a com­ parison of the engineering methods that were employed is also of interest. Fig. lOa provides the details over the years. This shows that around 3/ 4s of the overall driven length of transport tunnels were executed by mining means and around 1/4 by cut-and-cover. This applies both to

10;Sm;! 3500 870 4230 167 425 33 9225

Table 3. Excavated length and volume of the tunnels under construction at the turn of 1994/95

186

inner-urban Underground, urban and rapid transit system construction as well as to transport tunnels in general. A further aspect that springs to mind in conjunction with Underground, urban and rapid transit system construction is that at the turn-of­ the-year 1994/95, good 18 km, representing a ratio of almost 2/5 of the overall driven length, was completed using tunnelling shields. The ratio for shotcreting methods is also roughly 2/5. Of particular interest, last but not least for the construction industry is the tunnel construction volume anticipated in the near future (5 to 10 years). The relevant fmdings obtained from the end-of-the-year survey 1994/95 are contained in Table 4. This construction volume of around 340 km of transport tunnels will largely be realised by the year 2000 according to the latest level of planning. Apart from 55 km of Underground, urban and rapid transit railway tunnels, the volume of 181 km of long-distance rail tunnels and 104 km of road tunnels is really remarkable. With respect to the road tunnels, it should be said that the measures currently being prepared in the Eastern German federal states are still at the pre-planning stage, which means they are not far enough advanced to safely be included in the statistics. The 104 km of planned road tunnels contained in Table 4 have at least reached the planning approval stage. In addition, it appears as far as we can say at the moment that 89 road tunnels with an overall driven length of approx. 125 km have been additionally planned. They have to be added to the values contained in Table 4. T~e

Underground. urban and rapid transit systems Long distance railway Road Total

~

55 181 104 340

Figure 10. Data on trenchless and cut-and-cover construction methods in conjunction with the traffic tunnels under construction at the turn-of-the-year (length-related)

Planners and contractors are of course greatly interested to know the locations of the planned tunnel projects. Fig. 11 contains a break-down of the planned tunnelling volume according to the federal states.

Figure 11. Classi­ fication accor­ ding to federal states for planned and registered traffic tunnel pro­ jects (construc­ tion starting as

10'm' 4.260 24.900 13.720 42.880

from 1995)

Table 4. Excavated length and volume of planned tunnels construction starting after 1995

187

EUROPEAN SITUATION CONCERNING THE SITUATION IN EUROPE

• A recently discussed special tunnel for transport of goods between South­ Germany and North Italy (Tunnel Tyrol) with a total length of about 150 km.

Numerous rail and road tunnels are in operation (Table 5) or are being built in various European countries. AB examples, the following major projects are either in operation, under construction or in the planning stage:

Traffic tunnels (route km) Metro Rail Road Austria France Germany Great Britain Italy Norway Spain Switzerland Total

15 270 550 200 60 20 200 1315

105 650 380 220 1150 260 750 360 3875

210 180 70 30 600 370 100 140 1700

• A tunnel undercrossing the 0resund between Denmark and Sweden with a length of 4 km. • A tunnel between France and Spain undercrossing the Pyrenees along the route between Narbonne and Barcelona with a total length of about 12 km.

Total

330 1100 1000 450 1810 650 1050 500 6890

• The Gibraltar Tunnel between Spain and Morocco, which will probably be about 50 km long. • The Mont Cenis Tunnel between France and Italy, again with a length of about 40 to 50 km. • A large number of tunnels within the framework of the planned pan-European high-speed rail links, scheduled to be completed by the year 2015.

Table 5. Rail and road tunnel operations in various West European countries (status 1990)

• Various tunnels planned in Norway beneath straits in order to connect islands with one another or with the mainland; the overall length will be greater than 100 km. A number of these tunnels will be more than 10 km long and will be constructed at depths of 600 m and more below sea level.

• The Channel Tunnel (rail) between Britain and France, which is approxima­ tely 52 km long came into operation at the end of 1994. • The Great Belt Tunnel (rail) in Derunark, between the islands of Funen and See­ land, which is about 7 km long.

Taking all these new construction proposal into account, the pan-European traffic tunnel network is likely to far exceed 10,000 km by the year 2000.

• The Alpine transit routes for rail traffic in Austria/Italy (the Brenner Base Tunnel) and in Switzerland (where the Gotthard Base Tunnel and the L6tschberg Tunnel are being contemplated), each approxi­ mately 40 to 50 km long. • An additional Alpine transit between Lyon (France) and Turin (Italy) with an estimated length of 54 km. 188

BIBLIOGRAPHY

Haack, A. (May 1995): Tunnelbau in der Bundesrepublik Deutschland: Statistik 0994/95), Anaryse und Ausblick; Tiejbau, Ingenieurbau, StrajSenbau 37 (995) 5, pp. 25-51 . Haack, A. (Oct. 1995): Vergleich zwischen der einschaligen und zweischaligen Bau­ weise mit Tubbingen bei Bahntunneln fur den Hochgeschwindigkeitsverkehr; book series ''Forschung Praxis, U- Verkehr und unterirdisches Bauen''; Alba-Fachverlag, Dusseldorj, 1995; pp. 251-256; paper pre­ sented to World Tunnel Congress, STUVA­ /ITA-Tagung '95, Stuttgart, May 1995. DIN 4030: Beurteilung betonangreifender Wiisser, B6den und Gase. STUVA, Ingenieurburo Philipp, Schutz & Partner (PSP) (994): Expertise ''Einscha­ liger/zweischaliger Ausbau mit Tubbingen fur ein- und zweigleisige elektrifizierte Eisenbahntunnel, die mit Geschwindigkei­ ten bis 300 kmlh befahren werden''; prepa­ redfor DB; 11 .1994. Deutsche BahnAG (1993): Eisenbahntun­ nel planen, bauen und instandhalten; DS 853, Ausgabe 10.1993.

189

CASE STUDY OF AN ALPINE TRANSIT FREIGHT TUNNEL CONCEPT· INFLUENCES OF GEOLOGY ON TUNNEL TECHNOLOGY j. Golser 1 ABSTRACT

in Europe and with the economical inte­ gration of the former East Block countries, demand for the increase of transportation capacities is steadily increaSing. The existing traffic lines, highways, freeways and railroads are at their capacity limit and are not adequate for the future needs. Truck transport causes problems for the environment like air pollution and noise. The existing rail transportation systems are either at their capacity limit or not attractive enough, so that most of the goods are transported on road. The Alps are a great barrier between the mediterranean industrial zones and the rest of Europe. Since the freight traffic volume between Italy and Northern Europe has doubled the last 20 years and it is expected to double again in the next 20 to 30 years the Alpine countries agreed to plan 6 new main transport lines through the Alps to transport 135 Million tons of goods per year. Austria has 3 main corridors from Germany to the south, the Pyhrn corridor to the Balken, the Tauern corridor to Italy and the Balkan and - the most important - the Brenner corridor, the con­ nection Munich - Verona.

The Alps build a barrier for the North­ South freight transit. Most of the goods are transported by trailers on freeways causing environmental problems. The freight volu­ me is estimated to double during the next 20 years which would lead to a traffic infarct on the existing roads and rail tracks. It is the policy in Europe to transfer long distance freight transports from road to rail. The mixed rail system, high speed passen­ ger traffic and freight transport is unefficient, costly and limited in capacity. It is proposed to construct a separate automized freight transit line through the Alps from Rosenheim to Verona. The ali­ gnment is underground in two single track tunnels. The total tube length is more than 500 km. Special TBM's are to be designed to cope with hard rock and great deformations of the rockmass due to high overburden. Lining systems are to be developed which allow considerable radial deformations. INTRODUCTION

THE PROBLEM

The global interweaving of industrial pro­ duction, the exchange of goods and the high mobility of people have caused a significant increase of transport volumes during the last decades. With the elimination of customs in the European Union, with the political changes 1

The connection Munich - Verona uses a corridor through Tyrol along the Inn valley to Innsbruck in East-West direction and then turns to south over the Brenner pass to Bolzano and Verona.

Prof. Dipl.-Ing. Dr., Mining University, Leoben, Austria 191

Tyrol has become the main transit corridor between Germany and Italy since Switzer­ land has strict restriction on transit freight transportation on roads. The environmental consequences with regard to air pollution and noise and the traffic congestions are an unacceptable burden for the people living there. Today more than 30.000 cars, 4.000 trucks and 130 trains use this corridor every day with maxima of 6.000 trucks per day. For the year 2010 it is estimated that these figures will be doubled. Such a scenario will cause an infarct on rail and road.

adjustment to the different required train velocities. The first step should be to separate pas­ senger traffic and goods traffic in the alpine bottle necks in the very sensitive areas like Tyrol. For the passenger traffic the rail net exists already, it has been improved during the last years. The alignment goes from Rosen­ heim via Wbrgi, Innsbruck and the Brenner pass to Bolzano in Italy (Fig. 1). With some additional improvements the passenger traffic can be managed in the future, if the existing railtracks are relieved from the transit goods transportation. The request for 250 km/ hour shall be reconsidered, a minimum speed of 160 km/hour should be acceptable in difficult alpine terrain.

What is needed in Tyrol is: • the relief of the roads from freight transit • an underground alignment for the rail freight transit • the passenger traffic shall be on the surface. The tourist who visit the Alps because of the beautiful scenery shall not be carried through long tunnels • the environmental problems must be solved in order to improve the quality of life for the people living in these alpine valleys.

PROBLEM SOLUTION

The transportation of persons and the transportation of goods have entirely dif­ ferent requirements. Passenger rail traffic should be high speed with trains in short intervals and with alignments at the surface. Goods traffic must guarantee delivery "just in time", high speed has no priority. The target must be to establish separate high priority rail nets for passenger traffic and for transportation of goods with the

Figure 1. Route comparison between separate traffic and mixed traffic

Goods shall be transported underground on rail on a separate alignment. IPG, International Planning Group, has proposed an entire underground solution crossing

192

the Alps from Rosenheim to Verona with connections to the existing rail net in Rosenheim, Worgl, Bolzano and Verona.

• The protection of people and environment. • The short construction time. • Reliability because of the simplicity of the system using proven components.

The total length of this alignment is approx. 350 km with 83 % in tunnels.

• Compatibility with the existing rail system. • Landscape protection because of under­ ground alignment.

The existing improved alignment for pre­ dominantly passenger traffic is approx. 424 km long with 5 % in tunnels. The proposed freight tunnels solution is compatible with the existing rail and rolling stock system of the European railways, which means, that every freight train can be taken through these tunnels in addition to the freight shuttle services between Rosenheim and Verona. Every freight, like cars, containers, trucks, trailers and semi trailers can be transported through this system.

• Environmental protection by transfer of transports from road to underground rail and by eliminating the necessity to widen the existing freeway. • Low running costs through automation. • Lower investment costs because of au­ tomized low speed operation and exclu­ sion of passenger transportation. This reduces substantially investment and maintainance costs for safety installations and ventilation.

Special emphasis is to be given to:

• Lower investment costs caused by the reduced cross sectional area for freight transport.

• economy • reliability and safety

TUNNEL CONSTRUCTION

• underground alignments

The alignment follows the shortest possible route from Rosenheim to Bozen and Verona. The project includes two single track tubes with 5.55 m internal tunnel diameter, con­ necting tunnels every 1.500 m for safety and maintainance purposes and crossovers at approx. 15 km distance (Fig. 2)

• environment • punctuality and guarantee of transporta­ tion time. Cost increasing characteristics, like high speed, are not relevant for transportation of most of the goods. The system solution for the cross-alpine freight transit is a fully automized under­ ground rail system in two tunnel tubes with conventional traction, using a loco­ motive each at the front and at the rear end of the train. The arguments for the separate automized freight transit system are: • To master the increasing freight volume in an economical way.

Figure 2. Route Municb- Verona- Tunnel profile

193

The longitudinal section and the alignment are chosen with longitudinal grades bet­ ween 0,2 and 1,5 % in order to consider the hydrogeological situation and to have enough headings to minimise construction time. The longest heading will be approx. 25 km, the other headings are all between 15 and 20 km long (Fig. 3). Most headings shall be driven uphill to reduce problems caused by water inflows.

Geology The alignment crosses the central East Alps in North-South direction and meets all the tectonical series from the Penninicum to the lower, middle and upper east Alpine

as well as the South Alpine. Fig. 4 shows only the longitudinal section from Raubling to the Puster Valley. The Penninicum from the Katschberg to the Brenner fault is also called the "Tau­ ernfenster" and is the tectonical lowest serie of the Alps. The Penninicum contains the central Gneisses, the Zillertaler Gneisses, as well as the lower and upper schist cover which enclose the Gneiss domes like onion shells. The Lower East Alpine is represented by the Innsbrucker Quartz phyllites. The Upper East Alpine contains the Nort­ hern Limestone Alps and the northern Greywake Zone. The South Alpine; south of the Puster­

Figure 3. Longitudinal section and construction time schedule Rosenheim-Bozen

194

Figure 4. Geological Section Bozen-Rosenbeim

Valley, is composed of Quartzphyllites, Quartzporphyr, and tertiary sediments, predominately carbonates.

Innsbruck Quartzphyllites: quartzphyllites, green schists, porphydro­ ides, marl, quartzite

From North to South we have the following lithological units:

Permomesozoikum: breccia, pyhllites, flint schists, thin layered carbonates

Flysch Zone:

Sandstones and chalky marls

Upper schist:

calcareous mica schist, prasinites, marls, quartzites

Northern Limestone Alps: limestones, dolomites, some chalky marls, greywakes, clayey schists and sandstones

Central Gneisses: granitic gneisses, migmatic gneisses and onatexites

Werfener layers: clayey schists, sandstones

Old Crystalline: paragneisses, mica schists, marls amphibo­ lites

Greywakes: phyllites, diabase, dolomite 195

Brixen Granites: biotitgranite

The classification system as we use it in

Austria is based on rock mass behaviour

during tunnelling and the main rock classes

are estimated to be:

Brixen Quartzphyllites: quartzphyllites, graphitic quartzites, mica schists, gneisses, porphyroids

Stable to slightly friable:

2 to 5 %; The rock mass behaves elastic,

minor local support is required.

Verrucano: basalt, breccia, conglomerates from the palazzoic quartzphyllites

Friable:

approx. 70 %; failure phenomena reach

shallow into the rock, equilibrium is reached

after short time.

Bozen Quartzporphyry: porphyry and tuff

Pressure exerting under low cover:

approx. 10 %; this category includes qua­

ternary valley fills and soft rocks with

failure mechanisms which may reach deep

into the rock.

Southalpine Mesozoikum: dolomite, Jura limestones, Oolith limestones Brixen Quartzphyllites: quartzphyllites partially chloritic, quartzites, gneisses, partially dyke rocks Southalpine Permotrias: Sandstones, dolomites, limestones, locally siltstones, marl

Pressure exerting rock under high cover:

10 to 15 %; this category includes greywakes

and phyllites in the Kitzbuhler Alps, mica

schists and possibly gneisses under the

highest overburden.

Main Dolomite: dolomite in thick layers with layers of clay schist

Tunnel Excavation and Support The economy of the project depends mainly on short construction time. The proposed alignment allows the excavation of more than 30 tunnel headings from 15 portals, the longest heading being approx. 25 km long. With this lengths conventional drilling and blasting is too slow. Consequently the project foresees two single track tubes for TBM excavation. The excavation diameter will be approx. 6.5 m. It is suggest, that a continuos TBM exca­ vation with continuos support application guarantees an average progress rate of 700 m per month. With this performance a construction time of 5 years would be possible. The short construction time con­ tributes to lower the investment costs.

Southalpine Mesozoikum and Tertiary: limestones, dolomite, marls

Rock mass classification So far only a very rough classification could be made based on general information about strength and deformation parameters of these rock types and on experience with underground constructions in these formations. Special attention must be paid to the high maximum overburdens, 1.200 m in the northern and southern limestone alps and 2.400 m in the central alps, causing high primary stresses. 196

The TBM must fulfil certain requirements to cope with high deformations. Radial deformation due to high primary stresses are expected to be in the range of 10 to 20 cm, in extreme situation they may be 30 cm and more. With shielded TBM's precast element sup­ ports can be installed. Continuos excavation with simultaneous installation of a final single shell prefabricated lining promises the highest advance rates. Due to the expected deformation the TBM shall be able to cut variable diameters with a variability of say 30 to 40 cm in diameter. The shield should be variable in diameter so that it cannot be blocked by the squee­ zing rock. A short gripper shield construc­ tion could be a solution. It gives the pos­ sibility to install precast elements and reduces the risk to be blocked in squeezing ground. The precast element support allows radial rock deformations in the range of 5 cm depending on the joint details and the backfill grouting of the gap between exca­ vated rock and precast ring. Radial defor­ mations more than that will require special yielding elements in the longitudinal joints. Since more than 20 TBM's will be in ope­ ration simultaneously in very different geotechnical situations it seems not advi­ sable to stick to one excavation and support system for the total length of 500 km tunnel tubes. For tunnel sections with a considerable percentage of highly squeezing ground an open TBM seems practical because this TBM is not so vulnerable to be squeezed or blocked by the rock. With an open TBM a single shell shotcrete lining with high strength shotcrete in combination with systematic bolting seems a good solution. To cope with high deformations special deformable elements may be used in lon­ gitudinal deformation slits in the shotcrete shell.

Probe drilling and drilling of dewatering holes parallel to the continuos excavation process is one additional requirement and challenge for the TBM developers. For mucking the use of conveyer belts may provide advantages compared to conventional mucking trains.

CONCLUSION

The project idea is based on a concept which separates passenger traffic from the rail transport of goods. Underground freight transportation on rail has great advantages compared to the mixed traffic such as environmental protection, higher capacity, greater reliability and lower cost. Great effort is required to improve and develop further TBM technology to cope with the extraordinary challenge of hard rock in combination with high primary stresses and great deformations. The concept of "Low Cost Transit Systems" offers chances for the European traffic policy, for the benefit of economical pro­ sperity and for the quality of life in a highly industrialised Continent.

197

STATE OF THE ART OF THE JAPANESE TBM TECHNOLOGY • NEW DEVELOPMENTS T. Hanamura ABSTRACT

The construction investment in and inter cities is still vital need in Japan and the high rate of investment is forecasted to keep in thefollowing 20 years. In this situation the tunnelling technologies keep toplay important roles. Among them a TBM technology will play a major role in the highly mechatronized construction techno­ logies to pursue the high efficiency of excavation and to attain the cost reduction. Japan has greatly contributed in the shield TBM technology and the new technology developments are spouting out. The TBM for rock tunnels is obtaining the important position in the rock tunnelling in Japan. In this paper extensive developments which are being carried out in Japan will be discussed and introduced. CONSTRUCTION INVESTMENT IN AND INTER CITIES AND TECHNOLOGY PROGRESS 1)

The 20th century can be called a century of industrial society with mass production and high efficiency as its goals. Japan has experienced and succeeded in achieving the mass-production capacity of an indu­ strial society, and now faces an information and globalization society. However, Japa­ nese citizens encounter difficulties and strains in and inter cities such as: skyroc­ keting land prices, traffic congestion and the lack of traffic infrastructure for roads, railways, harbors and airports, the lack of green and open space in cities, the lack

1

of urban infrastructure for sewage and garbage disposal facilities, earthquake vulnerability, etc. These are some of the issues that Japan have faced as a result of urban congestion problems. The construction investment in and inter cities is still vital need in Japan. The amount of Japan's investment in construction is large enough and exceeds that of USA or major European countries. The high growth rate of investment is forecasted to keep in the following 20 years. It predicts that the development and redevelopment in and inter cities continue to be big in Japan. Most of the large cities of Japan are located in the estuary part of the river, where geological conditions are mostly soft and weak by the alluvial soils near the surface. Since the land available for industrial use was limited, the most of those structures have been built in the estuary and coastal zones including reclaimed lands. However the large quantity of the lands is covered by mountains in Japan. Inter cities traffic connections have to cross mountainous areas. Roads and railways have to excavate tunnels in the mountain and build bridges over the valley. Japanese tunnel engineers have encoun­ tered the difficulty in geological conditions from soft soils to hard rocks . Engineers had to fight with the soft soil problems in urban areas, and have developed techno­ logies of land fill , land improvement, foundation engineering including pile foundation, slurry walls and shield tunnels. New technologies have also been introdu­ ced for the mountains. Tunnels have to

11, General Manager, Technology Development Dept. 11, Taisei Corporation, Tokyo, Japan. 199

be excavated sometimes in the extremely hard or soft rocks such as volcanic rocks in order to keep the traffic priority of the planned route of railway and roads. Engi­ neers had to fight with the difficulty of geology from weak soils to hard rocks. Just after the world war 11 Japanese con­ struction industries were greatly influenced by the technology of the United States. Introduction of heavy equipment to dam projects for hydroelectric power station was called revolution to the Japanese construction technology. Japanese construc­ tion industries had noticed the importance of new equipment and technologies. Con­ struction industries were eager to import new technologies from developed countries in 1960's and 70's. Construction industries imported both technical know-how and equipment. The drill-and-blast method for rock excavation and the shield tunnel method for soil excavation were those typical ones. Japanese engineers absorbed and digested the imported technology, and revised and developed to the new techno­ logy of their own. NATM was introduced in Japan in 1970's, and almost at the same time the mobility system in the tunnel construction had been gradually changed from rail system to the rubber tire system. NATM was introduced to cope with swelling rocks at first in Japan. However gradually NATM had been adop­ ted in many mountain tunnels and became the standard rock tunnel method in Japan. Though TBM had once been introduced for some rock excavations in Japan at that time, TBM could not function well for the susceptive rock, specially weak rocks in Japan. Since then, most of Japanese tunnel engineers had not much interested in TBM for long time. Only small numbers of engineers have noticed the importance and have tried to use TBM occasionally with the strong understandings of owners. However recently Japanese engineers have

concerned much with TBM and eager to apply into Japanese rocks since Japanese engineers have been enlightened by the recent remarkable achievements of TBM technologies attained in US and in European countries. Japanese engineers have been stimulated by the extensive use of TBM in varieties of rocks and the efficiency of high speed excavation and low cost construction. Japanese tunnel engineers have classified into two main schools of excavation me­ thods as: the rock excavation school with drill-and-blast or mechanical means and the shield tunnel excavation school for soils. Shield tunnelling school engineers come from the experience of soil excavation including cut and cover methods for city infrastructures. Rock tunnelling school engineers come from the experience of rock excavation mainly in railway tunnels at the beginning, afterward road tunnels involved, with know-how and highly me­ chanized equipment such as hydraulic drilling machines, mechanized excavators, mobile systems with the rubber tire. Recently the new big waves are surfing among Japanese tunnel engineers. The first set of waves is changes in the integra­ tion of rock and soil engineering as a continuum media engineering. Though design standards are completely different in two schools in Japan at this moment, two school engineers have begun to col­ laborate one another to introduce more economical and fast way of excavation and to integrate both systems in the desi­ gning. Euro Channel Tunnel project gives them a strong impact on the use of the shield tunneling method with the segmental lining into the rock tunnels. There are some tunnel construction cases where one shield machine is used continuously both in rocks and soils in one project. The effort to conform two design methods has been contrived and some measures were achie­ ved in some projects. The NATM has been 200

gradually introduced in the excavation of soils instead of using shield method in urban area of the city. NA1M had not been applied for long time in urban areas of Japan, since Japanese engineers had been afraid of ground settlements by the lowering of ground water table during and after excavation. Because the mountain tunnel­ ling method induding NATM allows the draining of water into the tunnel, NATM had not obtained the reliability in regard to the ground settlement. Therefore most of Japanese engineers have placed much confidence in the dosed type of shield tunnel methods which does not allow water drain into the tunnel at all, specially for the settlement suceptible soils in the alluvial soft ground. The second set of waves is the extensive use of TBM into more rock tunnels in Japan. High speed and low cost are key words in tunneling construction in Japan nowadays. Japanese engineers have noticed the efficiency of TBM from the achieve­ ments attained in US and in European countries. Engineers have more interests in TBM and have begun to use TBMs more for both temporary and permanent exca­ vations in the rock tunnels. Japanese ma­ chine makers are also eager to enlarge their capabilities of machine productions not only for soft soils but also for hard rocks since they have suceeded in supp­ lying TBMs for the Euro channel project with know-how of shield tunnel machines.

tunnels need the large sectional area for multiple lane use. The road tunnel with three or more lanes need the span of more than 20m. Though the railway tunnel itself is not becoming large, the some of the cross-sectional area needs the large span of the tunnel for the enlarged part of multiple train lines or the station. Since the deep underground construction is getting popular in urban areas of Japan, even the subway station itself is constructed by the tunnel method, not by the cut-and­ cover method. Therefore large areas are excavated by some special tunnelling me­ thods. At the same time, the excavation of large diameter tunnels generally contributes the lowering of costs. A deep excavation is a vital need in urban areas of Japan. Depth that has been utilized in tunnels in the urban areas is up to around 40 m at this moment. Some of the structure has exceeded more than 40 m in depth. They are vertical shafts and shield tunnels for underground river for flood water reservoir, sewage lines and pump stations, underground high voltage power lines and power substations, ete. In future, it will be used up to around 100 m below the surface. In deep underground, high earth pressure and water pressure will act on structures. High earth pressure acts when excavation takes place as the stress in the ground is liberated. High water pressure acts on the lining systems of the structures. High pressures require the supplemental support for the ground and the thick linings though it raises the cost of construction.

The span of 20 m in diameter and the

depth of more than 50 m is a present target

of the tunnel technology in urban areas of

Japan.

TTRENDS OF TECHNOLOGY INNOVATION General Trends in Tunnelling Technology inJapan The construction of large diameter tunnels is one of major trends in tunnelling con­ struction in the world. The area of tunnel cross-section is becoming large. Road

201

Development of Modern Shield Tunnel Technology Japan has contributed two major advance­ ments in a modem shield tunnel technology for soft soil excavation. One advancement is the development and promotion of the closed face mechanical shields (closed type shield) tunnel technology which have been used extensively throughout Japan since 1960. The slurry shield method of the closed type has been developed tunnels of wider diameters and attained the dia­ meter of 14 meters. Another advancement is the invention of earth pressure balance (EPB) shield. The earth pressure balanced shield has a unique system that the chamber between the ground face and the bulkhead is always filled with excavated soil with some admixture which helps to prevent water inflow and retains the tunnel opening. As a transformation of EPB, a rheological foam shield tunneling method was de­ veloped. By adding foam in the face and the chamber, the face pressure has stabilized and face retainability has increased. By adding foam-removable admixture into the excavated soil, the soil becomes normal state from slurry state and is able to dump into the normal disposal area in Japan.

Diversification of Modern Shield Technology

Extensive Use ofTBM in Rock Tunnels in Japan

In US, there is a conference called the Rapid Excavation and Tunneling Confe­ rence (RETC) with the history of over the 25 years. Tunneling industries in US have made the great effort to attain the rapid excavation and to reduce costs. One of the most important trend is the use of TBM. TBM technologies in US have pro­ gressed successfully with technical innova­ tions. Same is in European countries. The use of TBM for the mountain rocks in Japan had been somewhat behind among the developed countries in the tunnel constructions. However recently TBM has been used for the construction of penstocks and headraces in hydroelectric power stations. For a construction of the inclined penstock shaft, a TBM is used for drilling the center pilot tunnel upward and a reaming TBM is used for the widening of the pilot tunnel into the penstock tunnel downward. For the road construction, a TBM is used for the pilot tunnel and then the whole tunnel is widened out to use multiple lanes tunnel. In this way TBMs have begun to be used in many purposes in Japan. The TBM technology has been greatly paid attention as the rapid excava­ tion method.

NEW DEVELOPMENTS IN SHIELD TUNNELLING TECHNOLOGY

The modem shield tunnel technology has a big trend of diversification such as: a large diameter excavation, a deep excava­ tion, a free shape excavation, a multiple face excavation, a sharp edged curving tunnel or a rotating shield tunnel from vertical to horizontal or vise versa, a me­ chanical underground docking of two tunnels, further systemization of full auto­ mation for excavation and logistics, etc.

Shield Tunnel of 14 meters Diameter in Trans-Tokyo Bay Highway 2) 3) 4) 5) The Trans-Tokyo Bay Highway is a 15.1 km long highway which consists of under­ sea shield tunnels, two man-made islands and bridges crossing Tokyo Bay. Kawasaki Man-made Island was constructed at the midpoint of the undersea tunnel where 202

the water depth is 28m. Kawasaki Man­ made Island is a cylindrical concrete struc­ ture of 98 m outside diameter which is surrounded by the annular steel jacket. The total length of the tunnel between Kawasaki side to the Kisarazu Man-made Island which connects to the bridge part, is about 10 km. Two tunnels are constructed in parallel. Two tunnels starts from Kawa­ saki side and Kisarazu Man-made Island. Four tunnels starts from Kawasaki Man­ made Island in which each two tunnels starts in parallel to the Kawasaki side and two to the Kisarazu Man-made Island. Each two tunnels meet in the underground of undersea and are jointed in between three points of Kawasaki side, Kawasaki Man­ made Island and Kisarazu Man-made Island. Features of the shield tunnels are described as follows; 1) Type of shield machine:

Slurry type

2) Outside diameter of shield tunnel: 13.9 m (machine diameter: 14.14 m) 3) Length of each shield machine drive:

2.5 km approximately

4) Cover of the ground in undersea part:

10 to 18 m

5) Hydrostatic pressure: 6 kgflcm2

6) Geological condition of surrounding ground: Extremely weak alluvial soil 7) Seismic condition:

Need to be considered

8) Estimated time of tunnel completion: 1997 The special features of these shield tunnels are that the tunnel is the world largest class of diameter with the shallow cover depth of very soft ground in the undersea part and that each tunnel facing one another will meet in undersea part and will be jointed in the ground. The construction of tunnels now receives the peak time and it will continue in the next year.

Shield Tunnel with Continuous Multi­ ple Circular Sections Japan has developed two types of systems with continuous multiple circular sections. One is a system called the Double-O-Tube (DOn which is an earth pressure balance type shield having multiple circular cross sections in the same vertical plane. Another system is called the Multi-Circular Face (MF) Shield which is the closed type shield and can use both slurry and earth pressure balance type. Each of both systems occupies the smaller projected area on the surface

Figure 1. Courtesy of Trans- Tokyo Bay Highway Corporation and Japan Tunnelling Association

203

compared with the area projected by plural tunnels. This benefits the easier planning of the route of tunnel lines in the congested urban area and reduces the cost for land acquisition and construction.

a. Double-O-Tube (DOT) Shield Tunnel 2) 6) The DOT tunnelling method is a unique system of simply mechanized EPB shield and can excavate multiple circular cross sections at one time. Each circular face has a set of radial cutter arms. Multiple sets of arms rotate simultaneously with synchro­ nized control of arm revolution so that each set of arms does not touch and collide with each other. One example is the con­ struction of subway called the Rijoh Shield Construction Project for the new transpor­ tation system in Hiroshima.

Figure 2. Courtesy ofMinistry of Construction and Taisei C01poration

1) Machine size:

10.69 m (5.345 x 2) wide x 0 6.09 m high x 10.7 m long

Osaka which will be used for a subway station. This tunnel technology construct the whole station with the platform and two train lines at one time. The center circular face produces a large spacious area for the platform and concourse.

2) Length of tunnel: 850 m 3) Soil condition: Unstable alluvial viscous soil and solid sand 4) Construction period: 1989 - 1992

1) Machine size:

7.8 m high x 17.3 m wide x 9.7 m long 2) Length of shield tunnel: 107 m 3) Depth of tunnel bottom: -35 m from the surface

b. Multi-Circular Face Shield Tunnel 3)7)

4) Cover thickness: 27m

A Multi Circular Face Shield is composed of two or more circular cutter faces in continuous two or more vertical planes which overlap each other. Each face has an independent circular cutter and can be changed in size. One example is the Triple Circular Face Shield Tunnel constructed in

5) Soil condition of tunnel part: Mix layers of sand (N > 50) and clay (N = 8 - 25) 6) Construction period: 1991 - 1996 204

1) Vertical shaft: OD. 0 5.7 m x 38 m deep 2) Horizontal tunnel: 00.02.75 m x 433 m long 3) Depth of horizontal tunnel: (Average approx.) 34 m 4) Machine size: (Vertical shield) 0 5.82 m x 9.71m long (Horizontal shield) 0 2.89 m x 5.16 m long 5) Soil condition: Dilluvial sand (N > 26), clay (N = 7 - 29) and alluvial clay (N < 9) 6) Construction period: 1993 - 1995 Figure 3. Courtesy of Osaka Municipal Transportation Bureau and Kajima Corporation

Rotating SWeld Technology

b. The Horizontal Sharp Edged Curving Tunnel

3) 8)

The horizontal sharp edged curving tunnel is another application of the rotating shield technology which is applied into the hori­ zontal plane. Since the sharp edged curving tunnel is in the horizontal plain as a whole with some differences of depth included, this tunnel can use the earth pressure balance shield system. One of the example is the horizontally rectangular curving tunnel constructed in Kawasaki which is used for the connecting water line between a rain water reservoir and a pump station.

The rotating shield has a spherical head which rotates and a new small shield machine starts to excavate out of a spherical head. The examples of using this techno­ logy are a Vertical-Horizontal Continuous Tunnel and a Horizontal Sharp Edged Curving Tunnel.

a. The Vertical-Horizontal Continuous Tunnel The vertical-horizontal continuous tunnel system consists of a main shield machine for vertical excavation with an incorporated sphere that houses a built-in sub-shield machine for horizontal excavation. When the main vertical shield reaches the specified depth to turn, the sphere rotates 90 degrees and the sub-shield starts continuously from the vertical tunnel to excavate a horizontal tunnel. The slurry shield and the reverse circulation systems are used for vertical excavation and the slurry shield system is used for horizontal tunnel excavation. One example is the sewage works in Tokyo.

1) Inner diameter and length of tunnel:

(Main tunnel) 0 4.5 m x 260 m (Sub-tunnel) 0 2.8 m x 65 m 2) Machine size: (Main shield) 0 5.53 m x 7.3 m (Sub-shield) 0 3.68 m x 4.635 m 3) Depth: (Average) 11.5 m 4) Soil condition: Silt (N = 2 - 4) 5) Construction period: 1992 - 1994 205

Figure 4. Courtesy of Taisei Corporation

Double Tube Shield Technology (provisional naming) This is a newly developed shield technology and may be called the Double Tube Shield Technology. The main shield machine houses an incorporated sub-shield machine. The main shield machine will excavate first a larger diameter tunnel and later a smaller diameter shield machine will start from the main shield machine. This technology adapts first to the subway construction in Tokyo. Though this subway line has normally two train lines, some special part of three train lines is constructed for an emergency pull-out line plus normal two train lines. The construction has just started.

3) Main shield machine: 014.18 m x 10.695 m long 4) Sub-shield machine: 09.7 m x 10.675 m long 5) Cover depth: 15 m 6) Soil condition: Mudstone 7) Construction period: 1995 - 1998

Figure 5. Courtesy of Sato Kogyo Co. , Ltd.

1) Tunnel length of emergency pull-out

area: 370 m (triple train lines) 2) Tunnel length of normal train lines: 700 m (double train lines)

206

Non-circular Section Shield Tunnelling Method There have been developed several types of the non-circular section shield. As typical examples of developments, two method will be discussed. One is the flexible section shield tunnelling method. Another is the elliptical excavation face shield method.

a. Flexible Section Shield Tunnelling Method 9) The flexible section shield tunnelling me­ thod can excavate various cross sectional configurations. The excavation system is composed of a main cutter and more than one auxiliary cutters called planet cutters. The planet cutters are fitted to the swing arms and swing arms themselves are atta­ ched to the main cutter. Swing arms rotate while revolving with the rotation of the main cutter and the stroke of swing arms is computer-controlled by the hydraulic jacks. This tunnelling method was applied to the construction of the sewage line in Tokyo. 1) Tunnel length: Figure 6. Courtesy of Tokyo Metropolitan Government and Taisei Corporation

564.95 m 2) Tunnel method:

b. Elliptical Excavation Face Shield Method 10) 11)

EPB 3) Shield machine outer diameters: 3.16 m (vertical) x 4.66 m (horizontal)

The system is combined with a circular disc cutter and supplemental excavating equipment called swing cutters and slide cutters which make full face excavation possible. The elliptical excavation face shield method will be used in the multi­ purpose conduits in Nagoya area.

4) Minimum radius of tunnel curve: 20m 5) Depth: 13 - 20 m 6) Soil condition: Dilluvial sand and clay

1) Tunnel length: 540 m

7) Construction period: 1992 - 1993

2) Tunnel method:

EPB 207

3) Tunnel dimension: 7.45 m (vertical) x 5.0 m (horizontal) 4) Shield machine outer diameters: 7.95 m (vertical) x 5.4 m (horizontal) 5) Cover depth: llm

6) Soil condition: Gravel include boulder of 0 0.3 m 7) Construction start: 1995 NEW DEVELOPMENTS IN ROCK TBM TBM use for Pilot Tunnels

TBM was used for the excavation of pilot tunnels in the road tunnel project in Kobe. The main tunnel was excavated by the TBM for pilot tunnels at first and then widened out by the slot drilling method. Two pilot tunnels were driven first by using TBMs and then other part of the tunnel cross-section was enlarged by the slot drilling and by the conventional enlar­ gement methods such as controlled blasting in blocks, use of large breakers or large hydraulic wedges.

Figure 7. Courtesy ofHonshu-Shikoku Bridge Authority,

Japan Tunnelling Association and Okumura Corpora­

tion

TBM FOR INCLINED PENSTOCK TUNNEL TBM has been used for the excavation of steep inclined penstock tunnel for the pumped storage hydroelectric power stati­ on. A special set of TBM is used for the inclined penstock tunnel near the Tokyo area. First a smaller TBM for center pilot tunnel is used to excavate upward from the bottom part of the horizontal penstock tunnel, and then the pilot tunnel is widened out by the reaming TBM to excavate down­ ward from the top. In order to prevent the backsliding of TBM during the excavation of the pilot tunnel, the backsliding preven­ tion reaction members and ring structures are equipped in the tunnel. TBM moves upward by the shield jacks with bearing the thrust on to the reaction members and ring structures. In every 40 m, anchored

1) Tunnel size:

8.964 m high x 15.736 m wide 2) Area of the tunnel cross section: 77.0 m 2 3) TBM diameter and length: o 5.0 m x (583 m x 2 + 576 m x 2) long 4) Geological condition: Granite (unconfined compressive strength: 250 Mpa) 5) Construction period: 1991 - 1992 208

backsliding prevention segments are equip­ ped and the thrust is born by these seg­ ments.

REAMING TBM FOR ENLARGEMENT OF EXISTED TUNNEL (RENEWAL TBM)

1) Diameter of penstock tunnel:

The rearning TBM has been used to enlarge and renew the existed tunnel. Following is an example of the enlargement of existed headrace tunnel for the renewal of the existed power station installation by using the reaming TBM in Kyushu island.

07.0m 2) Length of penstock tunnel:

771 m x 2 tunnels in parallel 3) Angle of inclination of penstock tunnel: 52.5 0

1) Diameter of tunnel excavation:

4) Diameter of pilot TBM: 02.7 m

04.31 m 2) Length of tunnel: No. 1 tunnel: 1509 m No. 2 tunnel: 4319 m

5) Diameter of reaming TBM: 07.0m 6) Geological condition: Sandstone and mudstone

3) Geological condition: Slate, sand stone and conglomerate

7) Construction period: 1994 - 1997

4) Construction period: 1993 - 1995

Figure 8 . Courtesy of The Tokyo Electric Power Co., Inc. and Okumura Corporation

209

Figure 9. Courtesy of Okumura Corporation

Combined TBM for Two Phase Geology (TBM for Both Rock and Soil)

Mobile Tunneller The machine has been developed as the mobile hard rock tunneller for a variety of tunnel cross sections which is based on the TBM called Mobile Miner. This mobile tunneller incorporates both the hard rock TBM and the mobility of the roadheader. The horseshoe-shaped tunnels can be driven without using drill-and-blast methods with its capacity for cutting 8.1m high. The mobile tunneller is suitable for the tunnel excavation in urban areas of high environ­ mental sensitivities without making blasting vibrations and noise. The mobile tunneller has advantages to produce smooth walls, roof, and floor, and minimize adjacent rock loosening and damage generated by exca­ vation. The excavation capabilities of the mobile tunneller are descried as follows .

Combined TBM for two phase geology has been used in many place in the world. Following is an example of using this combined TBM system for the sewage tunnel construction in Hiroshima prefecture. The rock part of tunnel is excavated first by the equipped rock cutter-face, and then the cutter face is changed into the one for soil at the geological boundary point bet­ ween rock and soil. After the rock part is he soil part is excavated by the EPB shield method. The boundary area of changing the cutter head was geological improved by injection before TBM arrives at the area. Thrust force had been born by the shield jacks and steel segments all through the tunnel. 1) Diameter of tunnel excavation: 02.13 m

1) Area:

2) Length of tunnel: 873 m

50 - 80 m 2 2) Dimensions: Height: 6.1 - 8.1m, Width:

3) Geological condition: Rock part: Granodiorite (UCS = 500-700 kgf/cm2) Soil part: Sand 4) Construction period: 1995 - 1995

3) Shape: Variable cross section 4) Rock strength: UCS = 50 -250 MPa 210

9 - 12 m

REFERENCES

The mobile tunneller is applied to the road tunnel in Kobe. Some of facts are described as follows.

1) Hanamura, T(1995): Innovative Tech­ nology and Recent Developments in Japan, Technical Seminar of IFAWPCA 95 Bali (27th Convention)

1) Cross sectional area:

Upper half: 70.4 m 2 (Height: 7.4 m) Lower half: 19.1 m 2 (Height: 1.5 m) 2) Dimensions: Height: approx. 10 m, Width: 11.154 m

2) Japan Tunnelling Association (1990): Tunnelling Activities inJapan 1990

3) Shape: Horseshoe-shape

3) Japan Tunnelling Association (1992): Tunnelling Activities in Japan 1992

4) Rock strength: UCS = 100 - 220 MPa

4) Japan Tunnelling Association (1994): Tunnelling Activities in Japan 1994

5) Project period (include other tunnels): 1994 - 1998

Area: Dimensions: Shape:

5) Okumura, H., Wasa, Y, Abe, K, Kanai, M., Inoue, H, Yoshida, K and Watanahe, H (1992): Design and Engineering ofLarge Diameter Tunnel Lining System for Trans­ Tokyo Bay Highway, Towards New Worlds in Tunnelling, Vieitez-Utesa & Montanez­ Cartaxo (eds), Balkema, Rotterdam, pp. 269-276 6) Ishikawa, S. and Kiyoshi, M.(1992): Selection of the Shield Tunnelling Method for the New Transportation System in Hiro­ shima, Towards New Worlds in Tunnelling, Vieitez-Utesa & Montanez-Cartaxo (eds), Balkema, Rotterdam, pp. 45-52

50 ~ 80 m2

Height: 6.1 - 8.1 m

Width: 9 ~ 12 m

Variable cross-section

7) Kuzuno, T, Ina, S., Ikematsu, T and Nishida, S.(1995): Subway Station Con­ struction by Slurry Type Triple Circular Face Shield Machine in Artesian Water­ bearing Sand beneath a Building, Paper in 21st ITA Conference. 8) /toh, H, Kainuma., N., Fukawa, Y and Kaneko, K (994): Development of Vertical­ Horizontal Shield Machine, Tunnelling and Ground Conditions, Abdel Salam (ed.), Balkema, Rotterdam, pp. 355-362

Figure 10. Courtesy of Taisei Corporation

211

9) Kanabe, Y, Ishikawa, A. and Chiba, S.(1992): Development and Verification Tests of Flexible Section Shield Tunnelling, Towards New Worlds in Tunnelling, Vieitez­ Utesa & Montanez-Cartaxo (eds), Balkema, Rotterdam, pp. 203-212 10) Inokuma, A., Ishimura, T , Asakura, H , Fujii, Y , Asakami, Hand Nakamura, M.(1992): The Design of the Primary Lining for an Elliptical Shield Tunnel, Towards New Worlds in Tunnelling, Vieitez-Utesa & Montanez-Cartaxo (eds), Balkema, Rotter­ dam, pp. 213-220 11) Inokuma, A ., Asakura, H, Kiyoshi, M., Kaneko, K., Matsumoto, T and Nakajima, Y(J992): The Design for a Shield Machine with an Elliptical Excavation Face, Towards New Worlds in Tunnelling, Vieitez-Utesa & Montanez-Cartaxo (eds), Balkema, Rotter­ dam, pp. 221-228

212

BLOCK D TBM TUNNEL LINING / SEGMENT MANUFACTURING

FULL AUTOMATED TUNNEL SEGMENT PRODUCTION SYSTEM. A CASE STUDY.

R. Heilegger

I,

A. Beil

ABSTRACT

in an increase in the daily progress rates and therefore calls for a higher production speed in the production of the segments and makes new demands on the quality and, in particular, on the tolerances of the concrete segments. In the case of the world's currently largest tunnel project, the "Yellow River Diversion Project" in China, where a tunnel system with an overall length of 200 km is being built to supply water to several million people, daily progress rates of max. 60 mJday are being achieved in the fIrst section amounting to approx. 12 km in length with an excavated diameter of approx. 4 m. This means that with a ring division of 4 segments and a ring width of 1,6 m, there is a maximum daily requirement of 150 segments. Assuming that in the case of such large-scale projects such as transit tunnels crossing the Alps, several tunnel boring machines operations are proceeding at the same time, the even larger piece numbers per day and production plant would be realistic. In China, and with other large tunnel projects (e.g. Eurotunnel) the production of the segments gas until now, always been commenced with a relatively large lead so as to have a sufficient supply of segments at the start of tunnelling and in view of the relatively low productivity of the seg­ ment production. As a result, segment stores amounting to several thousand square meters (Fig. 1) had to be set up, a factor which leads to considerable increases in

Automation of tunnel boring machines (TBM's) results in higher daily progress rates which requires also a higher demand on segments at the same time. This paper deals with a research program with the aim to develop a full automated tunnel segment production system. For improving the technologies of the production using of high precision moulds, automation of the production sequences, quality assurance during process, quality control of the final product as well as a logistic transport system are investigated. To reach highest quality, mould design becomes important. Theoretical requirements on mould con­ struction and actual practical experiences are discussed.

INTRODUCTION

The manufacturing of the precast concrete segments for tunnel lining represents a considerable and often decisive cost factor. In particular, the construction of large-scale tunnel projects with automated tunnel boring machines and then the lining with segments does not only call for the further development of the mechanical technology but also makes new demands on the pro­ duction of the concrete segments. The further development of the tunnel boring machines results, in the fIrst instance, 1

2

2

Ing., General Manager of the Euroform Ltd., Cavenago di Brianza/ltaly Dipl.-Ing., D2 Consult, Linz, Austria 215

SOME REQUIREMENTS ON THE PRO­ DUCTION OF CONCRETE SEGMENTS

costs and to acceptance problems and is hardly possible in inter-city areas.

With the present relation, we would like to give you more information about the property concrete segments and show you the possible and different ways to produce them. The choice of systems especially depends on the follOWing elements: • Segment type In this case we should make a distinction between accuracy concrete segments for the final lining of the tunnel or pre-lining segments having only the structural function . Production systems is also determinated by particular features of the segment Le. holes, blockouts, parallel or tapered rings and so on.

Figure 1. Segment storage (Boston-Out/all Tunnel, MAlUSA)

In order to increase the productivity of the

pre-fabricated parts works to an exert that would correspond with the tunnelling requirements and so reduce manufacturing costs, a factor which today positively influ­ ences the ability to execute many tunnelling projects, in the coming years new technical and technological concepts will be required for segment production plants. The increased demands made on the geo­ metrical accuracy parameters particularly make vast demands on the design of the molds as regards rigidity, simple and safe operation and the frequency of use. In addition to this, considerations must be made as regards an economically and technologically purposeful use of automated or semi-automated machinery and plants and an economically and technically con­ vertible quality assurance and control of the continuous production process as well as the finished product. Here, in the search for new solutions one has to proceed from the actual project and the associated demands made on tunnel lining. Further­ more, the qualifications, the local features and the experience of the productions companies have to be taken into conside­ ration.

• Overall and daily production of the single segments or whole rings First of all, both the production depends on the scheduled feed of the TBM, on the possibility of storage both in the factory or in the building yard, and it depends also on the necessary concrete resistance that allows the use of segments with TBM in the tunnel. • Availability of an area to create a new factory or to use existing sheds, concreting plant, cranes, specialized man power. The production of segments could be awar­ ded to a local manufacturer considering also that in the center of the town there isn't usually any available area. On the other hand, for example, the Adler Tunnel plant in Basel had been installed directly at the job site with the advantage of reducing the transport costs of segments and to regulate in a easier

216

Fixed moulds

way the production output, according to the necessity of TBM. • Possibility of using one or more shifts a day. It is normally more advantageous to use more shifts and to employ steam curing than to use more moulds.

PRODUCTION METHODS

After taking into consideration the above mentioned elements, we produce to the choice of production system. We can use four different methods: 1 2 3 4

-

Fixed single moulds Carousel plants Batteries Longline moulds.

This system is usually used for a lower production and also in case that steam curing is not employed. The advantage of this type of mould is an casy action on the single mould in order to make repairs or changes without over­ drawing on the production's cycle. Another advantage consists of the possibility of inserts deshuttering according to the concrete resistance (for example after 2 hours). If a steam curing is not used, a considerable energetic saving expense is possible. The last advantage is that the steam curing cycle (precuring, main-curing, and post curing) can be easily respected.

Considering of the motion, those four systems are divided into two classes: a) Fixed formwork (i.e. production place) with all the other motion operations such as concrete transport, segments transport, reinforcement transport, etc. point 1, 3 and 4 are included in this class. b) Moving formwork with all operations in fixed place within a limited area. In this class are included carousel plants with steam curing.

Figure 2. Elevation and transversal section of a fiXed mould

Disadvantages are: more labour incidence, more energetic expense if steam curing used and more required production area, too. A vibration system expense is as high as the formwork's number. Concerning the use of batteries with vertical casting, we must stress that this system requires less space than single mould. However it is limited to special concrete segments that do not have tolerances and

ADVANTAGES AND DISADVANTAGES OF DIFFERENT MOULD TYPES

Before deciding on a final choice, we would like you to consider and disadvan­ tages of the decribed methods listed below. The advantages and disadvantages of the single mould system are summarized as follows: 217

do not include an high inserts number. The longline moulds manufacturing is used for concrete segment that by the point of accuracy are not demanding and also for concrete segment with few or no inserts.

PRIMARY FEATURES OF CONCRETE SEGMENT MOULDS

For a better understanding of the im­ portance of the moulds, we enumerate their primary features:

Moving moulds (carousel plants) • Ruggedness and structures in order to guarantee maintenance of initial dimensions after 1000 castings, too.

The advantage of this system is represented by a considerable productivity i.e. less required labour and less times as segment mould transport, concrete transport, rein­ forcement transport and placing and seg­ ment deshuttering. As it is a production line that works with fixed cycle time, it is easier to guarantee a steady production both by the point of quality and quantity. Infact, the crew always perform the same operations.

• Mechanical manufacturing and refmishing surfaces in order to assure the flatness of the segment contact surface. • Construction conception of the elements to be removed so that during the shuttering phase it will be possible to execute any other fittings with the purpose of letting the tolerances unchanged. • Exact choice of application points of vibrators as to obtain the best result, concrete features of the segment mould facades permitting. In particular, as concern formworks with horizontal casting, we have the follOWing primary components:

Figure 3. Example for a concrete segment plant - 3 line system

Another advantage is that the moulds neces­ sary to obtain the same quantity of concrete segments production are less i.e. the num­ ber of single moulds reuses is higher. The costs of the plant is normally less than the higher number of required fixed moulds in order to obtain the same production. If construction of sheds and covered storage areas is required, carousel plants need less area i.e. less investment costs. Concerning the vibration, the number of vibrators is less due to the vibration that takes place in a suitable vibration station.

Bottom Mould Bottom mould is composed by 2 side panels in bended sheet, reinforced on the whole surface. The sheet thickness takes into account the number of reuses without making heavy the formwork. In order to guarantee the highest precision, the bottom mould is assembled and welded in a special template. The structure of the bottom mould is duly stiffened to assure resistance to torsion. In 218

the vibrators area (under or on the sides) special supporting are put on with the purpose to avoid breaking of material and secure the best effect vibration.

and technologically purposeful use of automated and semi-automated machinery and plants. The use of such machinery and plants is, in the first instance, naturally dependent on the magnitude of the project Le. dependent on the overall costs, whereby today the following innovations are being increasingly used:

Front-shutters Front-shutters are composed of sheets of great thickness with reinforced stiffenings and are thermically trended before manu­ facturing on digital control machines. Front-shutters can be either fixed or hinged.

• full electronic control of segment mould moving

Side panels Side panels are manufactured in sheets of great thickness with strong stiffenings that resist torsion. The side panels are thermi­ cally treated before manufacturing on digital control machines. The side panels include a profile to get the place for the gasket and normally one male/female type in order to assure an easier assembly of segment of the tunnel.

• automated steel bar cutting plants • automated bending and welding units to manufacture reinforcement cages (Fig. 4) • fully electronic dosing and concrete mixing plants • fully electronic transport and additive facilities for the concrete

Brackets for side panels Brackets for side panels are equipped with a regulation system that allows for putting the same along the axes X-Y-Z. All this to obtain the possibility to make further regulations during segment production. The locking system with a special bolt secures the maintenance of the side panels position during the vibration and guarantees at the same time a good transmission of the vibration.

• fully electronic control mechanism for the final quality control of the segments

Cover panel The cover panel is hinged directly to the bottom mould in order to avoid damage of front-shutters. The locking takes place with a bolt that has qUickes locking.

Figure 4. Welding robot for segment reiriforcement cages

AUTOMATION TENDENCIES IN PRO· DUCTION

When considering the use of such facilities, the geographical situation and the resulting specific conditions (e.g . the qualification

In the automation of segment production, it is largely a question of the economically 219

of manpower, wages, technical standard) of the country in question play a role. D2 Consult, together with the Institute of Prefabrication Technology and Construction OFF) in Weimar, Germany and the Austrian company Uni Software Plus are developing, in the form of a research and development project, specifications for a master control stand, with the aid of which the entire production process can be monitored and controlled to enable large-scale construction projects with large piece numbers to be tackled. As the shortening of production times in the manufacturing of pre-fabricated concrete segments is restricted by the speed of the physical and chemical processes during the hardening of concrete, the intercoordination of the individual produc­ tion stages is increasing in significance. However, there is also the possibility of jointly controlling the tunnel rock drill as well as the segment production from the superposed master control stand (Fig. 5) so as to establish a dependency between the transport of the segments to the instal­ lation site and the tunnelling speed (just in time production).

fibre segments were used in the construc­ tion of four water supply tunnels in Italy and in the construction of the underground railway in Neapel. The practical use is also being tested in Germany. In addition to decentralizing the production process by doing away with the manufac­ turing of reinforcement cages and their placing into the mould, even shorter pro­ duction times are being achieved in these construction projects. The formwork for a segment with a thickness of 20 cm was able to be removed 2,5 hours after steam treatment. In addition to this, the use of steel fibres which often occurs at the edges during the erection of the segments can be reduced.

QUALITY ASSURANCE AND CONTROL

The automation of tunnelling means that high demands are made on the segment manufacturing process and in their erection. This results in a series of aspects arising as regards quality assurance and control, in particular for the segment manufacturing process. Here, in addition to the quality parameters of the material and rigidity properties, the geometrical accuracy parameters are increasingly playing a significant role. I. e. a high degree of precision is called for which already exceeds that of the standard manufacturing and control procedures. Consequently, what is required, on the one hand, are production-associated quality assurance and quality management systems which guarantee the adherence to precision parameters during production and, on the other hand, measuring procedures which perform a repeat check after production. The testing procedures, out of necessity, extend beyond the finished segment pro­ duct even to the moulds. Here it is largely a question of the cyclic examination and

Figure 5. System structure for a project supervision

THE USE OF NEW MATERIALS

As the use of steel fibre shotcrete is beco­ ming more frequent in tunnel construction, for some time now the use of steel fibre concrete has also been tested in the pro­ duction of segments. For example, steel 220

Task I: Optimization software program for segment production:

the realignment of the moulds as well as the automatic discarding of defective or inaccurate moulds. In the case of associated quality assurance, it is largely a question of reducing the production of defective segments in advan­ ce and, if possible, completely excluding such. In the case of such off-line quality assurance, the production stages which have a specific influence on material and geometric parameters are monitored. These include, amongst other things:

Based on the input of project specific parameters, it enables evaluation of several possible alternatives for segment produc­ tion. Further, upon defining values for certain technological production parameters it calculates the best possible alternative for segment production.

Task H: Development of a Quality Con­ trol Hand Book for segment production (Quality Diagnosis):

• handling the moulds,

The goal of this task is to develop a Quality Control Hand Book, which could be utilized for different tunnel segment lining produc­ tion. This handbook could be utilized for numerous international production scena­ rios, as it would take into account the applicable international codes and stan­ dards.

• the concrete prescription and the concrete production, • concrete vibration, • the installation of the reinforcement cages and the components to be installed, • the hardening of the concrete by heat or steam treatment.

Task Ill: Development of an off-line Quality Management Mechanism:

In the afore-mentioned research and de­ velopment project, D2 Consult, IFF and Uni Software Plus are preparing the concept for quality control and a quality manage­ ment which can be adapted for different types of segment production plants. The project can be subdivided into three major tasks (Fig. 6):

The purpose of this task is to develop a concept for off-line Quality Management Mechanism, which can be integrated into the computer to conduct, Quality Prognosis.

CONCLUSION

Further to the manufacturing and the pre­

paration of the single elements, the assem­

bling of all these components is very

important because decides the mould's

tolerances.

This operation must be made in our work­

shop with an highly qualified staff and

with suitable instruments of measurement

(micrometrical rods, location templates

manufactured at digital control).

Figure 6. Structure oJ the R&D Project "FLEX-CIM"

221

Concerning the possibility to plan and to use a full automatic plant we have to consider the following point: • In the production of concrete segments some people must be directly involved. For example during the opening of the mould, the placing of the lifting device, cleaning, oiling, the closing of the mould and the placing of the reinforcement cages (Fig. 7). This operations could be automatic but with very high costs. All the movings of the mould in a carousel plant are automatic.

Figure 7. Placing of a reinforcement cage

These are the considerations that should be done before starting with the concrete segment manufacturing. Overall it should be a good cooperation between designers of concrete segments, calculator of the segment structure, TBM manufacturer, the sealing suppliers and the segment produ­ cers.

222

QUALITY CONTROL ON COMPUTER CONTROLLED TUNNEL SEGMENT MANUFACTURING PLANT W. Liniger 1

ABSTRACT

of rated values is made possible through on-line data acquisition of relevant process data. The quality diagnosis mostly results only in a "good"- or "bad"- decision on the usability of the produced concrete element. Changes of production conditions which are necessary to eliminate the found quality deficiencies are only possible in off-line mode. The quality prognosis, however, aims at finding trend changes in the production process by current on-line data acquisition and analysis, detecting and correcting this way creeping parameter deviations in early stages, so that the concrete element repre­ senting the final product may be produced in stable quality. Trend changes in the production process are not only due to failures and defects, wear on wearing parts is not avoidable. Therefore a quality pro­ gnostic system has to give orders to carry out the prophylactic maintenance and if necessary to displace wearing parts. Ne­ cessary corrections in the production pro­ cess to a certain state are possible in on­ line mode. The prophylactic maintenance ensures the functioning of machinery and plants, so that the flawless production may be formulated as the goal of the application of quality prognostic systems.

New methods of computer-aided produc­ tion control and total quality management are necessary to produce concrete precast elements effectively according to the market requirements and quality assurance de­ mands. The production of precast tunnel elements makes especially high demands on the product quality, in particular concerning the compliance with geometrical parame­ ters. These quality demands effectively may be fullfilled only by means of process control systems and coupled with them quality assurance and quality management systems. There are described concepts which represent different developement stages of a complex process control system with quality diagnostic and quality progno­ stic components. As basis of the automation system are taken the object-Orientated process control system PROVBE which had been developed by the Institute IITB Karlsruhe - member of the Fraunhofer Society Germany (FhG) - as process visualization and control system PROVIS and adapted in co-operation of the FhG - IITP Karlsruhe and the Institute of Prefabrication Technology and Construc­ tion Weimar Reg. Ass. (IFF) as system PROVBE to the requirements of application in precasting works. The quality diagnosis is based on the principle, that the supervision of process parameters and parameters of the finished concrete element with regard to assurance in

INTRODUCTION

In connection with the introduction of certificated products European and Inter-

Prof. Dr.-Ing. habil. Wolfgang Liniger, Institute of Prefabrication Technology and Construction Weimar, Germany

223

national standards demand the application of quality management systems, for instance according to ISO 9000 ff, which not neces­ sarily are to be computer-aided, but may also be realized by documentations and instructions given from the company's management in connection with the ap­ propriate supervision measures. But the manufacturing of concrete tunnel segments requires such a high quality that it hardly makes sense to assure it without computer­ aided control. The production of segments for tunnel projects makes especially high demands on the assurance of exactly defi­ ned quality parameters, in particular regar­ ding the geometrical dimensions of concrete elements, for which tolerances have to be guaranteed within the range of ± 1 mm. Therefore computer-aided quality assurance and quality management systems are ur­ gently needed, they shouldn't however act seperately, but should be linked with existing or planned machinery and plant control systems, production and process control systems as well as with operating data aquisition systems as they are operating based on a great variety of process data. informations. Below will be described an approach to achieve this goal. It is based on experience which had be gained in the field of pro­ duction of small-sized concrete elements as well as wall and structural panel elements and it is applicable to the production of tunnel segments.

AUTOMATION AND QUALITY CONTROL - ACTUAL SITUATION IN THE CONCRETE PRECASTlNG PLANT

In the last years automation engineering and technologies have gained increasing significance in concrete and precast pro­ duction facilities.

224

The main goals of automation can be formulated as: • reduction of costs of production, • guarantee of realibility of the entire production process, • guarantee of quality characteristics which are uniform and reproducible, • faster and better production capacity utilization. Examples from the metal working and chemical industry show, that there are made extremely high efforts to realize these tasks. Partly there are used seperate, working at the same time independently from each other systems for production control, process optimization and quality control. Quality assurance systems are defined by the regulations of the ISO 9000 ff. A typical structure which demonstrates the connec­ tions between company and process ma­ nagement is shown in Fig. 1. From the ISO 9000 may be taken generally formula­ ted specifications for manufacturing pro­ cesses. Fig. 2 shows the derived from this principles for general runs in a precasting plant which are also typical for the pro­ duction process of tunnel segments. But on the whole all systems are operating on the same process data, which are only differently analyzed. In addition these systems are partly linked in different ways with higher level computer systems for production planning and control as well as for company management. Because of the costs it's not conceivable to introduce seperate systems for a concrete precasting work. A comparison with com­ panies of the chemical and metal working industries concerning the degree of auto­ mation shows immediately that the auto­ mation in concrete precasting works is still on a relatively low level.

Figure 1. Quality Management System with regard to ISO 9000 (source: WEIG4 Fachverlag Augsburg/Germany 1995)

As example there are given typical auto­ mation tasks and their realization according to Fig. 3.

that means a modular system with adaptable interfaces is in demand which thanks to the adaptability allows to avoid time­ consuming and fraught with errors basic code changes and achieve a fast adaptation to the basic control systems of various producers.

The realization of automation tasks in a precasting plant has to be payable. In spite of the high quality demands this also applies to the production of tunnel seg­ ments. This problem can be only solved by extending a process automation system based as far as possible on generally availa­ ble personal computer hardware by means of quality assurance components. To make the adaptation to special produc­ tion lines and their machinery and plants easier it has to be demanded a small extent of engineering and re-engineering work, 225

Figure 2. Aspects of tbe implementation of ISO 9000 in tbe prefabrication ofprecast elements

Ta. k

Stucbrd

T ....d

basic machinery controls

PLC

PC ba.ed

process vizualization

PLC based PC ba.sed

PC ba.ed

data base oriented process controls

interest to the production of tunnel ele­

ments. Instead of well-founded knowledge

experience and e mpirical methods are

used. Raw material differences due to the

deposit may already cause quality deficien­

cies.

But the above mentioned possibility to

determine correlations is of decisive signi­

ficance for solving the two follOWing kinds

of problems:

rllStstep.s

process optimization automated sto rage control automated agement

quality

man·

Quality Oing.nosis PCbasc:d

Figure 3. Typical tasks of automation and comparison with the actual state in the precasting plant

• calculation or estimation of expected output parameters based on the known input parameter constellations,

Being based on common process data the quality assurance and automation of the production process are closly connected. One of the problems which are not suf­ ficiently solved yet in the precasting industry is the unreliability in relating specific values of input parameters in the production of precast elements with the resulting output values of finished products, for instance gross density, strength values, resistance to outwashing etc., which are of special

• calculation of the necessary input para­ meter constellations in dependence on the demanded output parameters. In spite of some trials of mathematical modelling there havn't been achieved satisfactory results in this matter. The production of precast elements is a com­ 226

plicated non-linear physico-chemical pro­ cess which probably may not be simulated by deterministic models. Therefore it's necessary to use other correlation methods, for instance the method of computer con­ trolled teaching, non-linear classification, use of neural networks or fuzzy­ technologies. At present applications in this field are on trial. The mentioned above correlation possibi­ lities are of special interest in connection with the application of quality assurance systems, especially for the quality diagnositc and prognostic. QUALITY DIAGNOSTIC SYSTEMS

On principle quality diagnostic systems find out errors in production runs, but only when the error already happened. These systems diagnose shortcomings in the production process and analyse the reasons for a decrease in productivity. They require a developed information system and pro­ vide unlimited technical possibilities.

Statistically orientated diagnostic systems: These systems are generally placed into a level above the basic controls. Process, machinery, order and personnel related informations are gathered and analyzed which represent data of the past and, in general, may not be processed on-line. An efficient quality diagnostic system ac­ tually requires to combine both kinds of systems - the statistically orientated com­ ponents allow to analyze the knowledge of the past, whereas the error-orientated components allow to take into consideration actual status informations. The fact, that error analysis means analysis of happened errors, is an unsolved problem. Therefore quality diagnostic systems which however are necessary and have to be an integrated part of complex process auto­ mation systems are not capable to assure a flawless manufacturing. For this purpose quality prognostic systems are necessary, their development and application in the precasting industry are actual demands.

We distinguish the following kinds of quality diagnostic systems:

QUALITY PROGNOSTIC SYSTEMS

Error-orientated diagnostic systems:

In the end quality prognosis means that it may be predicted if the finished product will meet the quality demands or not. If it's foreseeable that quality determining problems will happen at a special stage of the production process it has to be tried to avoid this problems by interventions into the process control system. In case it shouldn't succed a correction the concerned concrete element could be taken out of the production excluding thus further money wasting working steps. But exactly this case should be avoided by quality prognosis, because this results represents the classical case of the quality diagnosis with the yes/ no-decision.

They are an integrated part of PLC systems and show the kind of error, the location of error as well as possible reasons for errors and give recommandations for eli­ mination. These systems get status informations from the PLC, are PC-orientated and more and more prOVided with auxiliary devices for troubleshooting, components of multimedia systems (CAD, computer animations, video recording explaining the replacement of parts and functional groups) are possible, also explanations in kind of symbols and clear text which support the application in developing countries. 227

The use of quality prognostic systems requires that the futur finished product parameters may be concluded from the actual process parameters. As already mentioned above a mathematical modelling did not bring positive results due to the complex character of tunnel segment ma­ nufacturing. Therefore another approach has to be founded. In priciple the production process of precast elements may be described by correlations between the input and output parameters. The basic relationship between input and output parameters is illustrated in Fig. 4.

Figure 5. Basic structure of a quality prognostic system

SCOPE OF REALIZABLE FUNCTIONS

The function of the process control system and of the quality assurance and quality management system (quality diagnosis and quality prognosis) are closely connected because of the access to the same process data and as far as the hardware is concerned may be realized at reasonable costs in kind of personal computer systems. The software may be realized by the real-time operating system OS/2, WINDOWS NT and WIN­ DOWS 95. The production process itselfs is overlayed with a first level containing programmable logic control units which is however not necessary for all phases of production. The higher-level process control system PROV­ BE forms the interface to other possible functions. A graphic process visualization is appro­ priate to the state of art. The data processing by means of a data base system creates the base for further analyses. Fig. 6 shows additional components of the entire automation system.

Figure 4. Input and output relations in the production of concrete elements

At present we are working on the applica­ tion of the above mentioned methods to get correlations between input and output parameters within the framework of quality prognostic systems. After integration of this methods we will get a quality progno­ stic system the basic structure of which is shown in Fig. 5. The quality control function unit realizes both the tasks of the quality diagnosis and the tasks of the quality prognosis. The possible feedbacks to the production process can avoid quality de­ ficiencies as far as it makes sense to take contermeasures in case of recognized deviations.

228

Figure 6. Survey structur of the automation system

NEW DATA PROCESSING POSSIBILI· TIES AND MEANS FOR QUALITY MA· NAGEMENT

This development work resulted in an information system which allows to place an information chip directly into the con­ crete element, where it is readable and may be written on without direct electric contact. Subjects of this information system are:

High quality demands are made on precast elements. Up to now it didn't succeed in putting unambigeous, durable and forgery­ proof marks concerning

• A family of semi-conductor chips, on which the information is written before placing it into the concrete element (read only chips) or where the existing pro­ duction and testing informations may be currently specified during the produc­ tion process (eeprom chips with write­ read-characteristics).

• the completion date, • testing results, • afterwards realized modifications or repairs directly on the precast element without conSidering its assembly conditions. There are used several marking methods, whereby optical marks of code or non-code type are applied, either in clear text manner or in bar codes. After handling the precast element these marks are no more readable. The institute IFF Weimar took the initiative to create in a research co-operation a line for designing information storage media to be integrated in precast elements which brought feasible results.

The characteristics of this chip family depend on the operating mode, on the necessary storage capacity and life-time. The scope ranges from battery driven chips which at present are readable at distances up to approx. 9 m, to passive chips with a virtually unlimited life-time, because an individual energy supply is not needed for them, but their informa­ 229

REFERENCES

tions are readable only at utmost di­ stances within the range of centimetres (approx. 50 - 80 cm). But this means already a lot.

Friichtenicht, H W, Liniger, W und Wern­ stedt, j. (1994): ProzejSautomatisierung Tunnelbau, Projektstudie IFF Weimar e. V/Germany

The integration into the concrete element requires that the chip stands up to the acceleration during the compaction. Several series of experiments clearly proved that these chips stand up to acceleration peaks up to 350 g (l) without problems.

jaschke, H-]. and Kummetsteiner, W (1995): Diagnostic Sytems for Acceptance and Superoision of Production Machinery and Systems, Concrete Precasting Plant and Technology, Issue 411995 pp 68 -81 Leist, R. und Scharnagl, A. (Hrsg.) (1993): Qualitatsmanagement - Methoden und Werkzeuge zur Planung und Sicherung der Qualitat (nach DIN ISO 9000if) Augsburg, WEKA Fachverlagfiir technische Fiihrungskrafte

• A generation of recording and reading devices with the following characteristics: - mobile operation mode, that means reading devices with a mini-display which allow to get immediately infor­ mations on the actual concrete element and at the same time to store the infor­ mation in a personal computer for a later access,

Wagner, H, Schulter, A. and Strohhausl, S. (1991): CONEX Tunnel Systems with Future, Part 1: Dowel Connections

MAYREDER Linz/Austria 3/1991 - stationary operation mode, that means writing/reading devices wich are directly coupled with the machinery and plants and are permanently linked with their control devices.

Wagner, H, Schulter, A . and Strohhausl, S. (1992): CONEX Tunnel Systems with Future, Part 2: Experiences in Realisation

MAYREDER Linz/Austria 8/1992

Special controllers which enable the com­ munication with PLC and PC control sy­ stems had been developed for both kinds.

concrete clement v.ith implemented infonnation chip

writing/reading device with controller,

memory and display

serial interface

PC station

Figure 7. System configuration for the application of an information chip implemented in the concrete element

230

SEALING GASKETS FOR YIELDING ONE PASS TUNNEL SEGMENTS

N. Herwegh

ABSTRACT

1

ved loading of the concrete, i.e. approx. 1000 T/m.

Within the framework of the EUREKA Research Project No. 1079 "CONTUN" entitled "Mechanized Tunnelling Under High Overburden", a development project is carried out to investigate sealing pro­ blems, especially in the region of the deformable elements which can be inserted in longitudinal joints as and when required, under the management of D2-CONSULT and with the firms Herrenknecht (manu­ facturer of tunnel boring machines), Phoenix AG and Datwyler Gummiwerke AG (manufacturers of seals), and STUVA as the scientific consultant and test institute. The solution presented in the paper con­ stitutes a sealing system that combines the deformable element and the lining seal, both made from synthetic rubber (EPR: ethylene-propylene rubber), wherein the main difficulty is to absorb the cross­ sectional compressive strain generated by a designed deformation path of 30 mm per element in such a way that the sealing function is not impaired.

• Highest possible initial load without deformation. • Absorption of forces from ring gap grouting up to 2 bars without deforma­ tion, i.e. approx. 200 T/m. • Water pressure to be absorbed 10 bars. Higher water pressures to be prevented or reduced by specific measures. • Joint gap widths: ring joints 0 - 5 mm, joint displacement-ring joint +1- 2 mm, longitudinal joint +1- 1 mm. • Sealing system to function for duration of the expected tunnel service life of 100 years. These inputs were supplemented during development in so far as to create a modular system which allows deformable elements to be placed in existing concrete formwork, if reqUired; also 2 per concrete segment as and when needed.

SPECIFICATION

The specification drafted by the project group includes the following requirements: • Deformation to be absorbed per deforma­ ble element 30 mm. • Force to be transferred to equal at least the maximum normal force at the appro­ Figure 1. Possible deformable rubber element arrangements

30 Chartered Engineer, Datwyler AG, Altdorf, Switzerland 231

Depending on the rock mass, a deforma­ tion-free design is permitted, or, if all possibilities are utilised, e.g. ring division into eight, up to 48 cm of deformation, in relation to the circumference of the lining.

DEFORMABLE ELEMENT

According to the specification the deforma­ ble element shall: • transfer 1000 T/ m of normal force, • allow deformation of 30 mm, • seal against 10 bars of water pressure in all joint and connection regions,

Figure 2. Deformable rubber element in longitudinal joint

known. In this case, it is only the designed deformation path and the total height of the element in its fmal state that are unusual. The geometry of the pure elastomer body was studied using the R&D calculations in order to achieve an optimum cross section. The study showed, however, that the ma­ terial volume was decisive not the cross sectional geometry. A lattice-grid structure that closed on one side was selected be­ cause of its ease of manufacture and its uniform conditions across the total cross section of the element. The endeavour to employ high quality elastomers most economically finally led to the consideration to use this latticed cross section as a formwork and to fill the cavities in such a way that they yield under external strain. Basically, two groups of materials can be used to fill the cavities:

• be insertable in the lining formwork, • combine with the actual lining sealing frame to make a deformable sealing unit. The almost inevitable result was a cross section-tailored rectangular body of the same dimensions as the cross section of the concrete segments. In order to absorb the deformation path of 30 mm, a defor­ mation element with an total height of 60 mm was selected. The inserted element is joined with the lining by and during the concreting process, constituting a single unit with the lining after formwork removal. The only parent substance conceivable for this task is a permanently elastic one which allows deformation of 30 mm from the original height. Moreover, a porous design is required with an air volume of 50% in its non deformed state and a solid body ratio of almost 100% on attaining full absorptive capacity, eliminating any further deformation. The viability of incompressible building elements comprising elastomers is long

• plastic deformable elastomers or elasto­ mer reclaims in an uncured state which under high pressure behave like liquids and can be squeezed out into the tunnel interior via openings.

232

• aerated, concrete-like building materials with a precisely specified pore volume. The first solution is notably efficient if yielding is to be controlled selectively across short sections, but it was not follo­ wed up, since to control a large structure like the one in questions proves too costly and the ejected material quantity of 12 litres per metre is too high. In contrast, the use of concrete with a high ratio of pores to fill the cavities is simpler, ecologically friendlier, a familiar technology, and the exposed concrete surface facing the lining element aids connection work. For preliminary tests, a single grid element was cut from the lattice and a test specimen made from EPR.

Figure 3. Sections of deformable rubber element consi­ sting of single chambers

This element was filled with aerated con­ crete of varying strength and pore ratio, and placed in a steel form to prevent any lateral yield under an applied load. After hardening, the absorption behaviour of the concrete was studied in a press.

233

Elements can be placed side-by-side as and when needed, even for large-scale tests with ring widths of 60, 90, 120, 150 or 180 cm. This facilitates full-scale tests on conventional concrete segments with existing formwork, eliminating the high conversion costs. THE ACTUAL SEALING FRAME

In accord with the modular principle, the sealing frame shall:

Figure 4. Test arrangement for a single chamber

The measuring results confirm the assump­ tion that the absorption behaviour of the rubber aerated concrete element can be influenced in the desired direction by altering the pore ratio and strength. D2­ Consult was mainly responsible for selecting suitable materials and it carried out the pressure tests in its own tunnel laboratory. After the preliminary tests, an almost full­ scale grid element was assembled, with all practical details, for a lining thickness of 40 cm, reduced to a theoretical ring width of 30 cm, thereby cutting testing costs, although all the sealing elements used in further tests were original parts.

• function with normal concrete segments without any deformable elements, as well as with elements with one or two deformable elements. For greater safety, the cross section was designed so that joint gap widths of 0 - 10 mm and a joint displacement of +/ 10 mm can be sealed safely. • withstand short-term loads in the labo­ ratory two or three times greater than operating pressures, i.e. 20 to 30 bars. The most difficult task was to guarantee the sealing function in the region of the deformable element where the seal is compressed by 30 mm to a height of 60 mm. This requires: • a deeper groove in the concrete and deformable element than in conventional concrete segment seals to guarantee a more reliable longitudinal displacement of the seal and a good seat. • reliable functioning of the groove in the deformable element under compressive strain. • a seal cross section geometry that resists compressive strain so that the actual sealing regions do not ripple under such strain.

Figure 5. Longitudinal joint with deformable rubber element, gUiding rod and gasket.

• distribution of compressive strain over a larger section as and when required.

234

• guaranteed sealing or sufficient sealing pressure for the entire service life of the tunnel. The cross section to meet these require­ ments differs quite considerably from the embodiments known today.

Thanks to a special elastic formwork profile deSigned for these seals which yields when the formwork is removed without damaging the concrete, the laterally ribbed section is anchored mechanically in the joint in order to retain it securely with the concrete segment without the need for a bonding agent. This opens up fully new possibilities for the adhesive itself: • for example, use of a highly plastic adhesive or primer coating to facilitate the displacement of the section in the groove, aiding the distribution of com­ pressive strain over a larger section. The adhesive can be designed in such a way that it fills transitions between deformable elements and the concrete, and compen­ sates for any unevenness caused by deformations. • on the other hand, the selection of a more rigid adhesive that absorbs the shearing force can eliminate the "keystone effect", i.e. the displacement of the seal profile within the groove.

Figure 6. Joint cross section

The cross section comprises: • a bottom absorption body which can be anchored in the groove, • a top sealing region, • a cavity in the sealing region to receive a longitudinal reinforcement, if required.

The aim here is only to show the possibi­ lities proVided by this type of groove design. We are fully aware that a tunnel site may not be used as a laboratory for adhesives and we therefore endeavour to prefabricate the seals for multiple functions in such a way that only one adhesive is required for mounting the sealing frames onto the concrete segments. To eliminate lateral yield, a round steel bar is placed into the cavities of the sealing body in the region subject to compressive strain before the corner is made. The bar and the enclosed rubber section produce a compressive strain body which largely resists longitudinal deformation, ensuring the required longitudinal displacement of the seal within the groove.

235

Seal

Deformatian- I . element

SYSTEM TESTING

Region of corn­ 'pressive strain

The functional characteristics of the system had to be tested under the interaction of all influencing variables:

Seal comer Opening Steel insert

• compression of the deformable element under pressure. • all joint types and corner designs, such as ring joints, longitudinal and bearing joints, sealing corners on concrete and sealing frame corners on deformable elements, under varying deformation conditions.

Figure 7. Gasket arrangement at segment corner

Sealing sections of the type described are extruded endlessly. To produce frames that enclose the concrete element, they are cut to length and placed in an angular mould. The actual corner region is injected at high pressure using fresh uncured rubber and is vulcanised with the aid of heat. The ends of the sections are affixed to the fresh rubber. In the mould, cross sections can be altered as the mould is similar to the formwork which defines the exterior di­ mensions. Before the section is placed in the mould, the round bars can be inserted into the open section ends, as and when required. The modular principle is adhered to in that the same devices are used to produce both reinforced and non-reinforced corners. At the same time, the mould is used to connect the two large cavities in the seal cross section outwards, i.e. upstream. The water pressure penetrates the cavities through the openings where it generates a high permanent sealing pressure, decisi­ vely assisting the long-term function of the seal. The pressure adapts as conditions change and is independent of the pressure that the sealing section itself creates and the respective joint gap opening.

• joint tolerances in the direction of the joint gap width and joint displacements, from minimum to maximum. • water pressure. Mini concrete segments tailored to the deformable element were made from rein­ forced concrete for a ring width of 30 cm and an element thickness of 40 cm.

Figure 8. Concrete test specimen

Figure 9. Concrete specimen with deformable rubber element, gasket. gUiding rod in original scale

236

The bottom element is joined to the de­ formable element and has a closed sealing frame, whereas the top sealing element receives only one sealing frame. The com­ bination of these two elements provides all the details of a longitudinal joint with a deformable element as well as one half of the ring joint, producing together with the two corners aT-joint. The adjacent element, which constitutes the other half of the ring joint, is replaced by a steel plate with a groove to receive the seal. The two steel plates are joined at an angle at which the differing joint gap widths can be achieved by means of a compressible joint disposed in the rear wall and the floor plate. The result is a water chamber dam­ med backwards, i.e. upstream, in which water pressure can build up.

The water chamber is closed from above by a pressure element which takes on the function of a top seal and, aided by hy­ draulic presses, can transfer pressure to the concrete segments to achieve the desi­ red deformations.

Figure 11. Test arrangement for deformation test and water pressure

Both the joint gap of the ring joint as well as the pressure in the water chamber can be altered by means of clamps and the deformation pressure created by the com­ pression of the element can be absorbed. Further 90° clamping elements prevent the concrete segments from being pressed out by the high water pressure. Simultaneously, the clamps can be used to adjust the joint displacement.

TEST RESULTS AND EVALUATION

With specific selection of the concrete strength and pore ratio, the desired com­ pressive strength can be achieved in the

Figure 10. Steelframefordeformation tests and water pressure

237

finished state and the intended absorption path for the deformable element attained. The latest research shows, however, that additional pressure elements must be in­ serted into the deformable element during production to delay the start of absorption. Watertightness without the deformable element was tested up to 20 bars. Water pressure tests with the deformable element have not be carried yet because the varying joint width within the test device cannot be controlled sufficiently. It was therefore decided to start with an infinite adjustment of the width of the ring joint region and to design the joint variably by means of replaceable metal inserts in so far as that joint widths of 0,5 and 10 mm can be set. The remaining tests are to be completed during the coming weeks. We believe that the concrete sealing system, together with the selectively integrable deformable element, is a promising building element as it easy to handle and flexible and can facilitate the application of the concrete segment construction method, even in tunnel projects with large rock overburdens.

238

DESIGN OF GASKETS FOR DEFORMABLE TUNNEL LINING JOINT CONFIGURATION. NEW DEVELOPMENTS. W. Grabe

1

ABSTRACT

EXISTING SOLUTIONS

Elastomeric compression gaskets, compres­ sed between segments of the tunnel lining, guarantee the watertightness of the tunnel at once and for the whole lifetime. Since the most impressive tunnel project, the Channel tunnel, PHOENIX has developed new gasket designs, which can accept greater gaps by using less rubber volume and which need lower closure forces. Deformable tunnel linings, which are used in tunneling with high overburden and waterpressure, require new developments. These new gasket profiles have to be watertight at high waterpressures and very large gaps between segments. Later they have to follow the gap reduction to 0 mm at the end of tunnel diameter reduction.

Since the Channel tunnel PHOENIX has fitted out several tunnels around the world with new developments. This was reported by Grabe and Glang (1993, 1995). The requirements, which had to be fulfilled, were • to reduce the rubber volume, • to accept greater gaps, and • to reduce the closure forces. To reduce the rubber volume by reducing the width of the groove is very important for transalpine tunnels, because the thick­ ness of the concrete segments must not be greater than 400 mm. The St.Clair gasket profile (Fig. 2) needs only 33 mm groove width compared to 50 mm of the Channel gasket profile (Fig. 1). At the same time the St.Clair profile (@ in Fig. 3 and 4) offers a watertightness of 10 bar up to gaps of 14 mm compared to only 5 mm gap with the Channel gasket profile (® in Fig. 3 and 4).

INTRODUCTION

Elastomeric compression gaskets for seg­ mental tunnel liners are used since more than 25 years for one pass constructed tunnels. For the Channel tunnel (Fig. 1) a special profile geometry has been de­ veloped to fulfill extraordinary requirements on permanent waterpressure of 10 bar in combination of 2,5 mm gaps and 15 mm offset between segments. For tunnels at the base of very high mountains, for ex­ ample the Alps, the tunnel lining can only be economically constructed, if it is de­ formable and thus reducing the outer earth pressures. Calculations lead to perma­ nent waterpressures of max. 10 bar in combination of initially 30 mm gap, later reduced to 0 mm gap. 1

Figure 1. Gasketprofile for Channel tunnel

Dept. Manager R&D AE Profile, Phoenix AG, Hamburg, Germany

239

Even the smaller brother of the St.Clair gasket profile, the so called Tokyo Route 12 profile (Fig. 5)' needing only 26 mm groove width, offers a watertightness of 10 bar up to 6 mm gap. This type of gasket profiles, which has been patented worldwide by PHOENIX, has a very good relationsship between watertightness efficiency, small groove dimensions and low closure forces. Therefore it is now proposed for the qua­ lification tests for the 4th tube of the tunnel under the Elbe river in Hamburg. The requirements are already very high, because they are expecting offsets of 20 mm con­ nected with an opening of the gaps up to 13 or 15 mm due to ovalisations which might be caused by tidal effects on the tube. The test pressure is 10 bar. FEM­ analyses and laboratory tests showed that a groove width of 46 mm, a groove depth of 19 mm and a gasket profile hight of 32 mm might fulfill the requirements tested on real concrete segments. Parallely another development has shown to be very efficient. It is the combination of a specially shaped compression seal and a swellable material which is clipsed into a small groove in the top of the compression seal. This PHOENIX develop­ ment is now used with very good results on Cachan-Charenton and Clichy-Labriche sewer projects in Paris and on BEWAG electric supply tunnel in Berlin. Parallely another development has been already tested. Compression seals with anchors (Fig. 5), that are cast in during the production of concrete segments, have shown to have better watertightness than the gaskets which are glued into the groove of the concrete segments. This is due to a prolongation of the leakage path under­ neath of the gaskets by the anchors (Haack and Schreyer, 1993).

Fig ure 2 . Gasket profile for St. Clair train tunnel

Figure 3. Load-deflection curves for different gasket profiles

Figure 4. Watertightness curvesfor different gasket profiles

240

NEW DEVELOPMENTS FOR TRANS ALP TUNNELS

Tunneling with high overburden and water pressure has been discussed in the euro­ pean working group Eureka EU 1079 "Contun". It took a lot of meetings to discuss the function of deformable tunnel linings and to fix the technical requirements that are needed for the design of elastomeric compression gaskets: • water pressure max. 10 bar, test pressure max. 20 bar • longitudinal joint gap between concrete segments initially 30 mm, during defor­ mation of tube finally reduced to 0 mm • transverse joint gap between segment rings max. 5 mm • offset in longitudinal joints max. 4 mm • offset between segment rings due to CONEX-dowels max. 2 mm • closure load (gap 0 mm) max 100 kN/ m • temperature 50°C.

Figure 5. Phases of production of concrete segments with anchored seals

For these requirements FEM-analyses and first laboratory tests were done to check the feasability. First it was decided to use different dimensions of the same geometry type in one gasket, the large one in the longitudinal joint, the small one in the transverse joint. Second it was decided to use a rubber compound with very low stress relaxation under 50°C tunnel tempe­ rature. The large profile with the St.Clair type geometrie needs a groove width of 100 mm, a groove depth of 50 mm and a gasket profile hight of 75 mm. The small profile will be the St.Clair profile (Fig. 6 to 8). Load deflection tests and stress-relaxation tests on the large proftlcs are already done. Watertightness tests will be done in 1996.

Figure 6. Glued in gasket profiles in the longitudinal joint

241

REFERENCES

Grabe, Wand Glang, S. (1989): Gaskets for segmental tunnel liners. World Tunne­ ling Grabe, Wand Glang, S. (1993): Gaskets for segmental tunnel liners, VIII Australian Tunneling Conference, Sydney Grabe, Wand Glang, S. (1995): Tunnel­ dichtungssysteme, VDI Conference, Braun­ schweig, Blastomere im Bauwesen, VDI­ Verlag Haack, A. and Schreyer, j. (1993): Bericht aber Wasserdichtheitstests an Phoenix­ Tunneldichtungsrahmen. Not published report of STUVA, Cologne

Figure 7. Anchored gasket profile in the longitudinal joint

Figure 8. Gasket corner for diformable tunnel lining

242

JOINT CONNECTORS FOR TUNNEL LININGS

E. Zenker l

ABSTRACT

• first of all, the connecting element should enable an automatically tunnel-lining to save time and to reduce manpower,

For software controlled tunnel lining instal­ lation mechanical connectors are necessary both to guide the segments during the installation process and to take over the pull out forces caused by gaskets. This paper describes a product which is able to provide all of that requirements. A special production method allows to pro­ duce a plastic material with high thickness, without any internal stress distribution and homogenous property. Based on this ca­ sting technology, called "POLO-RIM", the requirements for a mechanical connector could be reached. Successfully applications on projects in Milan/Italy, and in Paris/ France, confirm the high quality.

• quality improvement based on flexibility and elasticity, • symmetrical design, • small tolerances to guarantee function, • a reproducable large-scale production with economically costs, • high pull out force of concrete, • a shaping of the connectors, which should ensure, that the concrete holes would be simple to produce, • the connector or "dowel" should be suitable for the installation of concrete segments with weights up to 45 KN, • an elongation of the dowel, caused through the pressure of segment-gaskets, should be minimized. Roughly this has been the profile for the product which had to be developed.

The starting point for this contribution goes back to a publication of Dr.Wagner in 1981, where he describes the idea of "Basics of a new lining system for tunnels". The main item of this idea and the resulting coope­ ration between Dr.Wagner and Dr.Schulter on one hand and Poloplast on the other has been formulated and pointed out in a development - project, which has been started concretely in 1988 - the objective has been the realization of a connecting­ element in plastic instead of conventional steel-screws with the following profile: 1

The evaluation of the necessary design had to consider fit, form and function and resulted - step by step - after a lot of reflections, calculations and trials in a dowel, which is radially symmetrical and is devided into three stages in each of the anchoring areas with the segments. Each diameter area contains a tapered ring. The purpose of the graduated shape is to minimize the insertion forces while main­ taining a precisely determined insertion path.

Dipl.-Ing. Dr., Poloplast Kunststoffwerk Ltd., Leonding, Austria

243

The graduated form ensures that the dowel is guided along all contact surfaces at the same time, reducing the critical loads on the dowel during the erection of segments as well as the stress-peaks resulting from secondary bending forces due to the tole­ rance of entry and the guiding function . The tapered rings are a key to the holding power of the dowel (Fig. 1 and 2).

Figure 1

of force. A shape and force transferring anchoring is thus created, which is subject to only a slight deformation by the recovery force of the elastomer seal. The fastener just described is based on simple frictional engagement and requires no further inser­ tion parts or concrete undercuts (Fig. 3).

Figure 2 Figure 3. Radial joint with plastic dowel

Figure 1. View and section ofplastic dowel Figure 2. View ofplastic dowel

The significant and mostly specific problem in this point of development has been the fixing of the best production technology - in a comparison between all the conven­ tional plastic-technologies, may be for duroplastic or for thermoplastic polymers, there are a lot of limits to pay attention to. We started our efforts with the well-known injection-moulding, but in this technology it is unpossible to choose any thickness. We tried to create the dowel in the way of two half-pipes with ribs inside and to weld them together - because of the limiting material-thickness in injection-moulding of e.g. 4mm the Young's-modulus had to be extremely high to reach the desired tenacity for the dowel-body and the mate­ rials available are to expensive for a com­ mercial use.

For the realization and production in plastics this meant the selection of suitable materials and applicable technologies. Based on theoretical calculations it was evident that we would need two different types of polymers to reach all the high standards and demands for the designed dowel - on one side a "body" for the pick up and transfer of forces with an adjustable Young's modulus and on the other side a sufficient elastic material for the tapered rings, which can be compressed and com­ pacted during the insertion. After that insertion a part of this elastic material is pressed into the concrete pores. The resul­ ting compression bond between the con­ crete wall of the groove and the high strength body ensures a good application 244

Also the welding of the half-pipes has

shown out to be unsure.

So we decided ourselves for an absolutely

new way in the realization - which is called

"Monomer-casting".

Therefore a liquid mixture of Caprolactam,

a copolymer and a catalyst are cast in a

mould, where these monomers react on

the basis of a polymerisation to the ready­

made product.

The advantages of this technology have

been clear very soon:

Figure 4. Insertion Curoe-Diagram

• The polymer, which is built in the mould, is on the basis of Polyamide and the stiffness, tenacity and modulus are adju­ stable with the different concentration of the used monomers in the liquid mixture. • It is the only method to produce parts

with high thickness without shrinkage­ holes. • In fact of the casting of monomers the final product has no orientation, is the­ refore nearly free of any stress and is absolutely homogenuos in all room­ directions. Figure 5 . Pull out Curoe-Diagram

Only with this casting-technology we really could meet all the requirements for an auto-connector, which are described in the introduction: • high tenacity and high modulus, • minimal elongation, • perfect elasticity for insertion, • reproducable small tolerances, • high chemical resistance against unorga­ nic and organic solvents, acids and lyes in between pH 3-12. In combination with the elastic tapered rings the dowel leads to properties, which are shown in Fig. 4, 5 and 6.

Figure 6. Shear Curve-Diagram

A large number of practical tests during and after the developement and in the meantime the application of the described dowels or jointconnectors in tunnels which

245

have been built in Milano, in Paris, (Fig. 7 and 8) in Lille and now in Korea have shown the evidence of • technological advantages and • a further step in automatically tunnel linings.

Figure 7. Concrete segment with plastic dowels and gUiding rod (Project Eole, Paris/France)

Figure 8. Installation of Keystone segment with plastic dowel

246

PRECAST TUNNEL SEGMENTS REINFORCED WITH STEEL WIRE FIBRE REINFORCED CONCRETE (SFRC) • A STATE OF THE ART

D. Moyson INTRODUCTION

viour. The use of steel wire fibres provides a solution to the corrosion problem. It is clear therefore that steel wire fibre as reinforcement for tunnel segments, will play an important role in future projects.

Precast tunnel linings have been in use for many years in tunnel construction. Since their introduction, precast tunnel segments have undergone some important develop­ ments. One of the major developments has been the increase in unit sizes. To allow a faster progress, dimensions of the segments have increased substantially over the last 20 years. Today tunnel rings are wider and each ring contains less segments. In the seventies a tunnel ring consisted of 10 to 15 segments each 0,6 to 0,8 m in width. The elements were made of plain concrete with no reinforcement. Today, one tunnel ring consists on average of 6 to 8 segments each 1 to 1,5 m wide. To cope with the growing handling stresses, and the ever increasing jacking forces of todays more powerful tunnel boring ma­ chine elements now require reinforcement. A typical rebar quantity is about 60 to 100 kg/m3. The use of conventional rebar for tunnel segments, has however one major handicap in its limited durability. In aggressive environments mainly corrosion problems with conventional rebar have and still are being reported. Due to these problems and the ever increasing design lives, requi­ red for new tunnels, the future trend in segmental lining will put greater emphasis on durability. One of the major adavantages of SFRC, when compared to conventional reinforced concrete, is its excellent durability beha­ 1

1

LOADS ACTING ON TUNNEL

SEGMENTS

Figure 1. Different load conditions

Tunnel segments are subjected to a wide range of load conditions. The different load cases are represented in figure 1. In general, elements are demoulded 12­ 24 hours after casting. A high early strength and a good cohesion of the concrete is of prime importance to prevent damage to the edges and corners when removing elements from the mould. Also during demoulding, the element is subjected to bending forces as they are during stacking and transportation. When erecting the elements, the segments are subjected to impact. During the forward motion of the tunnel boring machine, the jacking shoes push on the previously installed ring. The compression load applied

Ing. , N.N. Bekaert S.A., Zwevegem, Belgium

247

on one jack can be as high as 600 tons. These jacking loads are very dangerous since they cause tensile stresses in the elements perpendicular to the tunnel axis. The tensile stress concentrations in a tunnel element subjected to a concentrated jack load is represented in figure 2.

cages, consisting of stirrups and longitudinal bars parallel to the segment border, resist the jacking forces of the tunnel boring machine. The reinforcement should also resist the tensile stresses acting perpendi­ cular to the tunnel axis.

Figure 2. Tensile stress concentrations in a tunnel element subjected to a concentrated load

Two zones with high stress concentrations can be identified. The first stress zone appears at the surface, the second more centrally. Since these stresses are very high, the jacking forces are generally the deter­ mining load case for design. Once the elements are installed, they form the tunnel lining and resist ground loads. In humid or aggressive environments or in case where a severe design life is requi­ red, a good watertight and a highly durable concrete lining is indispensable.

Figure 3, A conventional reinforcement cage

In practice, the reinforcement cage proves very often to be insufficient. Damage at edges and corners occurs (figure 4 and 5). Due to the minimum cover requirement needed for protection against corrosion, and the shape of the edges, the concrete is unreinforced over the outside 5 - 8 cm allowing high stress concentrations at the edges to break the unreinforced concrete layer. Since the concrete is brittle it will spall until it reaches the reinforcement. The joint will also be removed. The water­ tightness of the tunnel lining can no longer be guaranteed and waterseapage becomes unavoidable. Steel bars exposed to the atmosphere will start to corrode. The corroding bar will expand and spall into other parts of the concrete. Hence, more reinforcement will be exposed and start to corrode. The corrosion process goes on until the complete deterioration of the tunnel segments.

CONVENTIONALLY REINFORCED SEGMENTS

A conventional reinforcement cage consists of rebars fabricated into top and bottom mats, separated by stirrups welded to the mats. In general the amount of reinforce­ ment varies between 60 and 100 kg/m3, depending on the size of elements and load conditions. The main function of the top and bottom mats is to resist the bending forces related to demoulding, stacking, transportation and ground conditions. The edges of the 248

Figure 4. Spalling of a joint in a particularly vulnerable profile

Figure 5. Cracking and spalling of the concrete in the cover zone at the joint of a segment

STEEL WIRE FIBRE REINFORCED CONCRETE TUNNEL SEGMENTS

Technical advantages The spalling problems encountered using conventional reinforcement can be avoided by the use of steel wire fibres. Compared to convential reinforcement, steel wire fibres proVide a better resistance against

spalling due to the homogeneous distribu­ tion of the fibres and their excellent dura­ bility. The steel fibres are randomly distri­ buted in the concrete so providing an excellent reinforcement. Steel wire fibres close to the surface, ensure a correct reinforcement at the joint segments by removing the unreinforced cover zone. The other major advantage of SFRC is its excellent durability. SFRC, unlike structural reinforced concrete, will not support the classic galvanic corrosion cells. The fibres, being non-continuous and discrete proVide no mechanism for propagation of corrosion activity. Moreover, the risk of spalling is totally excluded as the increase in volume due to corroded fibres is not sufficient to split the concrete. Hence, it is clear that, compared to conventional reinforcement, the spalling of concrete due to concentrated loads and corrosion, is Significantly reduced by the addition of steel wire fibres. In addition to the above benefits, steel wire fibres have other advantages. Steel wire fibres form a multidirectonal reinforcement providing a resistance to stresses in all directions. This is an important advantage since tunnel segments are sub­ jected to stresses working in all three dimensions. Hence, each fibre is fully utilized. Another advantage of SFRC is its improved impact resistance. Tests performed on blocks have shown that the impact resi­ stance of SFRC at normal dosages is about 20 times higher than for unreinforced concrete. A further benefit of using steel wire fibres is extremely good crack resistance. The high quantity of steel wire fibres, homoge­ neously distributed in the concrete, provides very effective crack control. Tests performed in this regard, have shown that with the addition of 20 kg/m3 of fibres, the width of shrinkage cracks are reduced from 1 mm to less than 0,2 mm.

249

Economic advantages

The tests were carried out with plain concrete and concrete reinforced with 30 and 50 kg/m 3 of Dramix® ZC 601.80. The first crack and ultimate load were measured. The crack development was studied. The joints had a convex!convex configuration. The nominal dimensions of the panels were 500 mm x 500 mm x 150 mm. A representation of the test set-up is shown in figure 6.

The production costs of SFRC tunnel seg­ ments compare favourably with those for segments reinforced with rebar cages. Although the cost of rebar is less than steel wire fibres, there are significant savings to be made by the elimination of manufactu­ ring, handling and storage of reinforcement cages. Time savings obtained by the elimi­ nation of the positioning of the reinforce­ ment cages, the use of automatic dosing equipment and the increased strength of SFRC at early age , result in increases in productivity. The use of steel wire fibres for the reinforcement of tunnel segments on the Fanaco hydraulic project in Italy allowed an increase in the number of production cycles from 2 to 3 a day. The use of steel wire fibres minimizes damage to segments during handling, transportation, ring building or pushing and thus reduces repair costs. For the Heathrow baggage tunnel, a damage level of less than 0,3 % has been achieved during production and tunnel works.

Figure 6. Test set-up f or the pan el tests

Test results The use of steel wire fibres as reinforcement for tunnel segments has been the subject of many test programmes. Up to now, more than 10 different test programmes have been carried out on SFRC tunnel elements. All the different programmes show the suitability of steel wire fibres for this application. The bending, shear, spalling and bursting behaviour of SFRC segments have been investigated and compared to that of conventional reinforced and plain concrete segments. In what follows , only a few test results will be discussed. However full details of all of the tests are given in the references.

The measured 28 day first crack and ulti­ mate load values are shown in table 1 and figure 7. Dosage ofDranWx® zc 601.80 (kgIm') Load .. first crack (\eN) Per~ntage InawJ.w (from

30 863

0 kg)

Ultimate Load (kN) Perc:entoge_~~_if!om~kg)

"" ""

J458

1139

J1'!'

Figure 7. Results of the pan el tests

250

.."

1993

2220

37"

52%

Table 1. Test results f or the panel tests

a) Heathrow baggage tunnel Pairs of concrete test panels were tested to determine the behaviour of radial joints.

50

1257

The results showed that the load at first crack was 32 % greater with 30 kg/ m3 of steel wire fibres than for plain concrete. When the steel wire fibre content was increased to 50 kg/m3 this increased to 46 % . The ultimate values at the corresponding fibre contents were found to increase by 37 % and 52 % respectively. From crack width measurements taken on the panels, it was clear that the addition of fibres reduces crack widths considerably. When compared with plain concrete panels, at a load of 1350 kN, the crack width is reduced by 5 1/2 times with a fibre dosage of 30 kg/ m3 and by 11 1/2 times at a dosage of 50 kg/m3.

The tests showed that when compared to conventional reinforcement, the load at a crack width of 0,2mm was 22 % lower for 40 kg/ m3 and equal for 60 kg/ m3. The ultimate load was 23 % lower for 40 kg/m3 and 7 % the lower for 60 kg/ m3. These tests are important, since they show that 60 kg/m3 Dramix® ZC 50/.60 give virtually the same resistance as 80 kg/ m3 of con­ ventional reinforcement. c) Dipenta For the construction of several hydraulic tunnels in Italy, SFRC have been used to manufacture the precast elements. Prior to the construction of these tunnels a large test program on SFRC tunnel segments was carried out by the contractor Dipenta. The behaviour of SFRC tunnel linings under the combined effect of bending moments and normal forces were investigated. Conventional reinforcement, plain concrete and 50 kg/ m3 Dramix® ZC 60/. 60 rein­ forced tunnel segments were considered. The amount of conventional reinforcement was 75 kg/ m3. The test results are repre­ sented in figure 9.

b) Bilfinger & Berger In cooperation with Bilfinger & Berger splitting tests have been performed on SFRC and conventionally reinforced seg­ ments. The SFRC segments contained 40 kg/ m3 and 60 kg/ m3 Dramix® ZC 50/.60. The tradional segments contained 80 kg/m3 if rebar. The test set-up is represented in figure 8, and the test results in table 2.

Figure 9. Results of combined bending test

Figure 8. Splitting test set-up Reinforurnent Rebatat SOkglm'

.......... ..........

60 kglm' Drvnix® 501.60

wKllh(kN) 3370

tntimlleLoad 3922

2640

""

3007

-21"

·23><

Mj...

""""",,Nopdo

....

""'"

Jubilee

F""",

'.1

3 riop

7.'

F""",

2_

6.'

"'"""'"

'00

7.3

(=)

3.

•• "••

'.'

2000

Uoilod " " - '

REFERENCES

3.

Branshaug T, Ramakrishnan V, Coyle W V and Shrader E.K., '~ comparative eva­ luation of concrete reinforced with straight steelfibres and collatedfibres with deformed ends'~ South Dakota School of Mines and Technology, 1978.

Table 3. Riference table for subway tunnels

p­

~BA)[I.s~

DJNNELS

""""'"

"""""""

--

....y

F...."

'I>Iy

......

,...,.

'laIy

M~

......

(