Feng Hudson R o c k E n With regard to construction on and in rock masses, the subject g of Rock Engineering Design, in combination with its supporting i n subject of rock mechanics, has been experiencing a significant e shift in approach thanks to advances in rock site investiga- e tion techniques, computing, access to information and site r monitoring. The current emphasis on safety, accountability and sustainability thus requires stricter considerations and greater i n reliability than ever before. g With a modern approach and anticipating future developments, D this volume introduces a fresh methodology suitable for the e design of all types of rock engineering projects, both at the s surface and underground. Guidance is provided on the nature i of modelling to support design, on flowcharts, on the informa- g tion required and on the procedure for the technical auditing of n modelling and design. Moreover, the use of computer programs, Rock model calibration through site observation, interpretation of computer results and virtual underground laboratories are de- scribed and explained. Elaborate case studies on the design and Xia-Ting Feng & John A. Hudson construction of a rock slope and of a large underground hydro- electric plant, as well as technical auditing protocol sheets with Engineering examples, further facilitate bringing theory into practice. Written by two eminent authors, this modern and illustrated guide on Rock Engineering Design will benefit engineers, con- tractors, clients, researchers, lecturers and advanced students who are working on rock engineering projects in civil, mining, Design geological and construction engineering. Templates of the protocol sheets can be downloaded from www.crcpress.com. an informa business Rock Engineering Design 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb ii 55//2244//22001111 66::1188::2200 PPMM Frontispiece Site investigation borehole core from a Chinese project, illustrating intense core d iscing as a result of high in situ stresses. 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb iiii 55//2244//22001111 66::1188::2222 PPMM Rock Engineering Design Xia-Ting Feng Institute of Rock and Soil Mechanics Chinese Academy of Sciences, Wuhan, China John A. Hudson Department of Earth Science and Engineering Imperial College of Science, Technology and Medicine London, UK 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb iiiiii 55//2244//22001111 66::1188::2244 PPMM CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2011 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20120620 International Standard Book Number-13: 978-0-203-09337-5 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the valid- ity of all materials or the consequences of their use. 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Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com Dedication This book is dedicated to Professor Lin Yunmei of North-Eastern University, Shenyang, China, who, as Professor Feng’s PhD advisor, stimulated his interest in intelligent rock mechanics methods, and to Professor Charles Fairhurst of the University of Minnesota, Minneapolis, USA, who, as Professor Hudson’s PhD advisor, kindled his interest in rock mechanics and rock engineering. 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb vv 55//2244//22001111 66::1188::2244 PPMM 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb vvii 55//2244//22001111 66::1188::2244 PPMM Contents Preface xv Acknowledgements xvii About the authors xix 1 Introduction 1 1.1 The purpose of this book 1 1.2 The structure of the book 2 1.3 The ‘long learning curve’ 2 1.4 Rock engineering design, related subjects and the future 3 1.5 Chinese rock mechanics and Chinese rock engineering 6 1.6 Examples of rock engineering projects in China 7 1.7 Problems remaining to be solved 10 1.8 Chapter summaries 13 2 The ways ahead for rock engineering design methodologies 15 2.1 Introduction 15 2.2 Modelling and engineering design approaches 16 2.3 The integrated design approach 19 2.4 Modelling approaches which utilise computer networks 22 2.4.1 Internet/Intranet/Local Area Network (LAN)-based parallel computing 22 2.4.2 Internet-neural network analogy 22 2.4.3 Why do we need collaborative research on the internet? 23 2.5 The idea of a Virtual Rock Mechanics Facility (VRMF) 25 2.6 Development of the method D, level 2, methods: ‘intelligent’ modelling 26 2.7 The integrated methodology for rock slope design 27 2.7.1 Determination of slope angle using neural network models 29 2.7.2 Recognition of failure modes using an expert system 34 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb vviiii 55//2244//22001111 66::1188::2244 PPMM viii Contents 2.7.3 Estimation of the stability of slopes and their safety factors using integrated intelligent methods 34 2.7.4 Comprehensive integrated intelligent system for slope design 39 2.8 Case example using the rock slope integrated design methodology 39 2.9 Chapter summary 44 3 Flowcharts for rock engineering modelling and design 47 3.1 Introduction and summary of earlier work 47 3.2 The rock engineering modelling and design process 58 3.2.1 Updated rock engineering flowchart 58 3.2.2 Steps in the rock engineering design process 59 3.2.3 Project purpose, constraints and key features of the site, rock mass and project 60 3.2.4 Establishing the design approach strategy via the modelling options 61 3.2.5 Utilising the principles of modelling and code implementation 62 3.2.6 Establishing and verifying/validating the design 64 3.3 Use of the procedure in three illustrative case examples 64 3.3.1 Illustrative Example 1: The design of a conventional tunnel—Design of the Qiaotou tunnel, Yuanmo Expressway, China 64 3.3.2 Illustrative Example 2: The design of the powerhouse cavern for the Shuibuya project, Hubei Province, China 66 3.3.3 Illustrative Example 3: The design of an underground radioactive waste repository in crystalline rock 79 3.4 Chapter summary 83 4 Specifying the information required for rock mechanics modelling and rock engineering design 85 4.1 Introduction 85 4.2 The different types of information required by the different modelling methods 86 4.2.1 Forward analysis and the eight basic modelling methods 86 4.2.2 Back analysis and the feedback information 90 4.3 Obtaining the required information and problems associated with site investigation and in situ monitoring 91 4.3.1 The site investigation 91 4.3.2 An information theory approach 91 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb vviiiiii 55//2244//22001111 66::1188::2244 PPMM Contents ix 4.3.3 Potential lack of communication between designer, site investigation personnel, construction personnel and monitoring—and the remedy 92 4.3.4 Recommended procedure for establishing the required information 93 4.4 Illustrative case examples 94 4.4.1 Basic rock slope: potential wedge failure, Rubha Mor, Loch Lomond, Scotland, UK 94 4.4.2 High rock slope at the Longtan Hydropower project, China 97 4.5 Chapter summary 108 5 Technical auditing of rock mechanics modelling and rock engineering design 109 5.1 Introduction 109 5.1.1 Purpose and principles of technical auditing 109 5.1.2 Information supporting the technical audit 109 5.1.3 ‘Soft’, ‘semi-hard’ and ‘hard’ technical audits and the audit evaluation 110 5.2 Demonstration Example 1: The procedure for technically auditing a site investigation measurement—in situ rock stress (soft audit) 111 5.2.1 Background 111 5.2.2 Auditing rock stress measurements 112 5.2.3 Discussion and conclusions relating to Demonstration Example 1 115 5.3 Demonstration Example 2: Technical audit of modelling for the design of hydropower caverns at the Laxiwa Yellow River site in China (Semi-Hard Audit) 116 5.3.1 The Laxiwa hydropower project on the Yellow River 116 5.3.2 Integrated intelligent recognition of model parameters for brittle rock masses in high stress fields 121 5.3.3 Auditing the modelling for the Laxiwa project design 164 5.3.4 Conclusions from the Laxiwa case example 166 5.4 Chapter summary 176 6 Case example of the design and construction of a rock slope 179 6.1 Introduction 179 6.2 Types and features of large rock slopes at hydropower stations 179 6.3 Flowchart for the design of large rock slopes for hydropower stations 179 77000077TTSS--HHUUDDSSOONN--11110022--0033__BBooookk..iinnddbb iixx 55//2244//22001111 66::1188::2244 PPMM