Book review

Book review

Rock Engineering Risk,John A.Hudson,Xia-Ting Feng.CRC Press/Balkema,Taylor&Francis Group(2015).572 pages.ISBN: 978-1-138-02701-5(Hbk),978-1-315-73857-4(eBook PDF)

The invaluable book reports the outcome of the work of the Commission on Design Methodology of the International Society for Rock Mechanics(ISRM)in the ISRM’s 2011-2015 term of offce during which Professor John Hudson acted as Commission President while Professor Xia-Ting Fengservedas ISRM President.It provides a sequel to the authors’previous book,Rock Engineering Design(Feng and Hudson,2011),which reported the work of the Commission in the ISRM’s 2007-2011 term of offce when Professor Feng acted as Commission President and Professor Hudson served as ISRM President.It is also the frst volume in the newly established ISRM Book Series published by CRC Press/Balkema of the Taylor&Francis Group,an initiative taken during Professor Feng’s recent term of offce as ISRM President.

At the outset,the writer must declare an interest.In his review of the authors’previous book,Rock Engineering Design,published in these pages(Brown,2012a),and in other communications with them,the writer suggested to Professors Hudson and Feng that they should concentrate the work of the ISRM Commission on Design Methodology in 2011-2015 on the general area of rock engineering risk.The authors acceptedthis suggestion and generously refer to this fact at the beginning of the Acknowledgements section and again at the beginning of the fnal chapter of the present book. In theirChapter2,theauthors also referin some detail toa paperon risk assessment and management published by the writer in this journal in 2012(Brown,2012b).Despite these references,it must be noted that the writer played no part in work of the Commission or in the preparation of this book,and so is able to act as a fully independent,but most interested,reviewer.

Just as the earlier book,Rock Engineering Design(Feng and Hudson,2011)was structured around an original fowchart of rock mechanics modelling and rock engineering design approaches,this book is structured around a governing fowchart of risk factors,presented as a frontispiece to the book and represented and explained in Chapter 1.From its second line,the fowchart is divided between those risk factors that can be considered before construction starts with the associated risk and epistemic uncertainty being reduced at that stage,and those risk factors arising from aleatory uncertainty that are encountered, and may be reduced,as construction proceeds.As is always the case with generalised fowcharts of this type,it is not always possible to allow in a relatively simple fowchart for all of the considerations involved in any particular rock engineering project or to distinguish clearly between all cases of epistemic and aleatory uncertainty,including those sometimes associated with the analysis, modelling and design stages and processes.

The remainder of this review will consist of discussions of the contents of the book’s six main chapters(Chapters 2-7),some brief comments on the book’s presentation,and a closing summary of the writer’s overall impressions of the book.

Chapter 2 provides an overview of uncertainty and risk in rock engineering,including an explanation of the concepts of epistemic or conceptual uncertainty(lack of knowledge)and aleatory uncertainty(lack of precise predictability),and a summary of approaches to risk management.Because they are not discussed any further in the book other than briefy in Chapter 7,the writer believes that the book would have beneftted from slightly more detailed treatments of some of the well-established general approaches to risk assessment and risk management.

Chapter 3 deals with the Rock Engineering Systems(RES) approach,and in less detail,with Auditing and Protocol Sheets. RES was a typically highly innovative and imaginative contribution made to the corpus of rock mechanics and rock engineering by Professor Hudson in the early 1990s.The writer has had a copy of the RES book by Hudson(1992)in his personal technical library since shortly after its publication,but must admit to having never understood RES as well as he did after reading the present Chapter 3.A feature of this treatment of RES is the large number of examples given of the application of the methodology to a range of rock engineering and other problems.The authors’purpose in including this comprehensive amount of material on RES was to demonstrate how studying the main project variables and their interactions can lead to the identifcation of areas of rock engineering risk and their potential treatments in the pre-construction stages of projects.

From the writer’s perspective(Brown,2012a),the material on Auditing and Protocol Sheets was among the highlights of the authors’previous book,Rock Engineering Design(Feng and Hudson, 2011).These topics are given less coverage in the present book.It is indicated in Chapter 3 and again at the end of the book in Chapter 8,that in the period 2015-2019 the ISRM Commission on Design Methodology intends producing a new set of Protocol Sheets for the auditing and evaluation of risk assessment procedures,or Risk Reduction Protocol Sheets.While acknowledging the fact that the preparationofthenewsetofProtocolSheetstogetherwiththenecessaryillustrativeexampleswillnotbeanentirelystraight-forwardundertaking,thewriterconsidersthatthedevelopmentoftheproposed sheets and their inclusion in the present book would have further enhanced the book’s already considerable value and utility.

Chapter4isentitled“Rockfracturesandinsiturock stress”.Itaddresses two of the major“before construction”risk factors, providing a number of instructive illustrative examples.The treatments of these two basic rock mechanics issues are considered to be highly valuable and informative in their own right,irrespective of their roles as primary sources of rock engineering risk.The chapterconcludeswithacasestudyof themodellingofinsiturock stress at the Olkiluoto site inwestern Finland,which provides a direct link to Chapter 5 dealing with radioactive waste disposal.As the authors say in their summary of the structure and content of their book in Chapter 1,“One of the most diffcult,if not the most diffcult,rock engineering challenges today is the design of a repository for the disposalofradioactivewastewhichwillisolatethewasteforthousandsofyears. The factors involved in reducing the risk of radionuclides migrating back to the biosphere at an unacceptable level are discussed in the rock engineering context”.There is a necessary emphasis on the systematic consideration of all coupled thermo-hydro-mechanical and other(e.g.chemical,geological,biological)processes and effects, together referred to as THM+.The RES approach is used to good effect in this application.Another feature of radioactive waste repository design that is not necessarily represented in the other rock engineering examples discussed in the book,or in the governing fowchart,is the need to consider the extremely long operating and the fnal post-closure stages of the life of a repository.

However,from the writer’s perspective,perhaps the major highlight of the book is the large amount of invaluable and largely original material,much of it previously unpublished,presented in Chapters 6 and 7 which together occupy no less than 324 pages or 57%of the 572 page book.These chapters report,in the main, the work carried out on the Jinping II tunnels and the Jinping II caverns,respectively,by members of Professor Feng’s group at the Institute of Rock and Soil Mechanics,Chinese Academy of Sciences, Wuhan,China.In their acknowledgements,the authors note that“Dr Qiu Shili and Dr Zhang Yongjie wrote thefrst drafts of Chapters 6 and 7,respectively”.It must be acknowledged that in western countries,we are not accustomed to seeing so much valuable data on major projects,including extensive monitoring data, made so readily available in the open literature.One can only speculate as to why this might be the case.

Chapter 6 is concerned with the risks associated with long,deep tunnels.Section 6.1 provides an informative introduction to the world’s longest deep tunnels and the major engineering hazards associated with them,including rockbursts in Chinese tunnels.It concludes with a fowchart that may be used to establish risk management for long,deep tunnels.Section 6.2 considers epistemic uncertainty analysis in the design and construction for long,deep tunnels,dealing with issues such as the geological setting,rock mechanical properties,in situstress conditions,groundwater infow through fractures and weakness/fault zones,project location,and the procedures of excavation and support,in line with the provisions of the governing fowchart.Similarly,Section 6.3 addresses the analysis of aleatory uncertainty in the design and construction of long,deep tunnels while,importantly,Section 6.4 is concerned withmethodstoassess andmitigateriskforthesetunnels.Therisks consideredare thoseassociatedwith rockbursts,waterinrush,large deformationsinweakrock,andlongtermstability.Thechapterconcludes with a detailed illustrative example of the risk assessment andmitigationof thedeeptunnels attheJinpingII HydropowerStation,China,and the authors’customary chapter summary.Much of Chapter 6 was prepared especially for this book as part of the work of the ISRM Commission on Design Methodology.

The fnal substantive chapter,Chapter 7,deals with the risks associated with hydropowercavern groups,againwith an emphasis on recent Chinese experiences.Section 7.1 discusses the development of large hydropower cavern groups,the need for a new approach to risk management for these complex underground structures,and presents an original outline fowchart for risk management for a large hydropower cavern group before and during construction.Section 7.2 presents an invaluable database of 60 large hydropower cavern groups in China.The number and scale of these projects simply boggles the non-Chinese mind.This section includes a detailed statistical analysis of the key issues infuencing rock mass behaviour around these cavern groups.Section 7.3 then considers epistemic uncertainty analysis dealing with a similar set of issues tothose considered in Section 6.2 in the context of long,deep tunnels,while Section 7.4 treats the corresponding aleatory uncertainty analysis.

Next,a detailed method of risk assessment for a large hydropower cavern group developed by Professor Feng and Dr.Zhang for the purposes of this book is presented in Section 7.5.This method,which is explained using a number of excellent fowcharts, is too complex to summarise simply here,except to say that it deals with a wide range of potential risks and uses a fuzzy hierarchy methodology.Finally,the application of this previously unpublished method is illustrated through the example of the assessment and mitigation of risk for the very large underground powerhouse at the Jinping II Hydropower Station,China.The treatment of risks before and during construction is considered.A set of 24 risk events potentiallyencountered during construction is listed,discussed and illustrated in Appendix A.As noted previously,the amount of detail provided in this illustrative example is quite extraordinary and,in the writer’s experience,lies well outside the usual limits of published case histories.

This book is extremely well written,easy to follow and wellpresented on high quality paper.Once again,the chapter summaries were found to be invaluable.Presumably in order to keep the book’s cost within affordable limits,none of the many excellent diagrams and photographs are presented in colour in the body of the text.A relatively small number of diagrams and photographs are reproduced as colour plates at the end of the book on pages 565-572.The writer believes that the clarity and value of a number of other fgures would have been enhanced by also reproducing them in colour.He has also advised the authors of a small number of errors,omissions and other infelicities noted in the text.In the writer’s opinion,the most signifcant of these items are the lack of an index and the non-inclusion of the proposed new Risk Reduction Protocol and Auditing Sheets(discussed above),both of which he suspects were occasioned,at least in part,by the wish to complete the book so that it could be published as the frst book in the new ISRM Book Series by the end of the ISRM 2011-2015 term of offce.

The publication of this book reinforces and adds to the already high reputation of the ISRM Commission on Design Methodology. It brings great credit to its authors,Professors John Hudson and Xia-Ting Feng;to the other members of the Commission on Design Methodology in the 2011-2015 period(their names are listed in the book’s Acknowledgements);to the staff of the Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan, China;to the ISRM itself;and to the publishers.The subject of the book is highly topical and is central to all modern rock engineering undertakings.The writer is pleased to be able to recommend this outstanding book unreservedly to all advanced students,researchers,teachers and practitioners in rock mechanics and rock engineering,particularly,but far from exclusively,those having an interest in underground excavations in rock.He believes that they will fnd the study of this book to be as rewarding as he did.

Brown ET.Book review:rock engineering design.Journal of Rock Mechanics and Geotechnical Engineering 2012a;4(1):III-IV.

Brown ET.Risk assessment and management in underground rock engineering-an overview.Journal of Rock Mechanics and Geotechnical Engineering 2012b;4(3): 193-204.

Feng XT,Hudson JA.Rock engineering design.Leiden:CRC Press/Balkema;2011.

Hudson JA.Rock engineering systems:theory and practice.New York:Ellis Horwood;1992.

E.T.Brown

Golder Associates Pty Ltd,PO Box 1734,Milton,QLD 4064,Australia

E-mail address:tbrown@golder.com.au.

Available online 26 June 2015

Peer review under responsibility of Institute of Rock and Soil Mechanics,Chinese Academy of Sciences.

http://dx.doi.org/10.1016/j.jrmge.2015.06.001