Synopses & Reviews
The main goal of this introductory course is to demonstrate how basic concepts in soil mechanics can be used as a "forensic" tool in the investigation of geotechnical failures. This, in turn, provides a good opportunity to show how to use available procedures in the formulation of useful simple geotechnical models. Geotechnical failure is understood here in a broad sense as the failure of a structure to function properly due to a geotechnical reason. Some of the geotechnical failures selected are well known for their impact on the geotechnical community. Others are closer to the authors' experience. They have been organized into three main topics: Settlement, Bearing Capacity and Excavations. They cover a significant proportion of every day activities of professional geotechnical engineers. No attempt has been made to create a comprehensive handbook of failures. Instead, the emphasis has been given to creative applications of simple mechanical concepts and well known principles and solutions of Soil Mechanics. The book shows how much can be learned from relatively simple approaches. Despite this emphasis on simplicity, the book provides a deep insight into the cases analyzed. A non-negligible number of new analytical closed-form solutions have also been found. Their derivation can be followed in detail. In all the cases described an effort was made to provide a detailed and step by step description of the hypothesis introduced and of the analysis performed. Each of the eight chapters of the book addresses a certain type of failure, illustrated by a case history. The chapters are self-contained. They provide a review of soil mechanics principles and methods required to understand and explain the failure described. In some cases the analysis offered provides a non-conventional application of basic principles. All chapters are completed with a summary of lessons learned from the failure and its analysis. They also include a short account on advanced topics to help the interested readers to go beyond the approaches used in the book. Readers are expected to be familiar with the basic concepts of soil mechanics and foundation engineering. The target audience is graduate students, faculty and practicing professionals in the fields of civil and geotechnical engineering. This textbook profits from experience accumulated in teaching a course in forensic engineering at the ETH Zurich.
Review
From the reviews: "The main goal of this text is to illustrate how basic concepts in soil mechanics can be used as a 'forensic' tool in the investigation of geotechnical failures. ... provide a detailed and step-by-step description of the hypothesis introduced and of the analysis performed. ... Each chapter is self-contained and provides a review of soil mechanics principles and methods. The target audience is undergraduate and graduate students, faculty and practising professionals in the field of Civil and Geotechnical engineering." (International Journal of Mining, Reclamation and Environment, Vol. 25 (1), March, 2011)
Synopsis
This introductory text uses basic concepts in soil mechanics to investigate geotechnical failures. It presents case studies of failures from the areas of Settlement, Bearing Capacity and Excavation and analyzes them from the perspective of soil mechanics.
Synopsis
It is not an easy task to fascinate a student with a standard course on Soil Mechanics and Geotechnical Engineering. If, however, the same material is presented as a tool to explore a natural or a man-made "disaster", both the motivation and the ability to absorb this material increase dramatically. The case studies in this book could help to build an introductory Forensic Geotechnical Engineering course, covering such basic topics as settlements, bearing capacity and excavations. The failure cases considered in this book have something in common - they can be all reasonably well explained using so called "back-of-the-envelope" calculations, i.e., without sophisticated models requiring finite element analysis. These simple methods based on clear mechanical considerations are the endangered species of the computer dominated era, though sometimes they could prevent a disaster caused by a wrong application of computer models. In particular, the upper bound limit analysis has repeatedly proven itself as a powerful tool allowing for sufficiently accurate estimates of the failure loads and leaving a lot of room for creativity. No one is exempt from making mistakes, but repeating well known mistakes reveals a gap in education. One of the objectives of this book is to attempt bridging this gap, at least partially. More failure cases covering a larger area of geotechnical problems are included into the companion book "Geomechanics of Failures: Advanced Topics" by the same authors.
About the Author
Alexander M. Puzrin, born in 1965, studied Structural Engineering at Moscow Institute of Civil Engineers (1982-1987) and Applied Mathematics at Moscow State University (1990). He received his Ph.D. in Geotechnical Engineering from the Technion - Israel Institute of Technology in 1997, where he joined the faculty. In 2002 he became a faculty at the Georgia Institute of Technology (USA). He has been Professor of Geotechnical Engineering at the ETH Zurich since 2004. Prof. Puzrin has been involved as an expert in geotechnical projects in Russia, Israel and Switzerland. His expertise lies in progressive and catastrophic failure and constitutive modeling of geomaterials. He is the author of more than 60 papers. Awards: Technion Excellence in Teaching Award in 2001; ASCE (Student Chapter) Outstanding Faculty Award in 2003; ICE Bishop Medal in 2004. Eduardo E. Alonso, born in 1947, got his degree in Civil Engineeering (Ingeniero de Caminos, Canales y Puertos) in Madrid in June 1969. He got a PhD in Northwestern University in 1973. At present he is Professor of Geotechnical Engineering at the UPC in Barcelona. He is the author of more than 300 papers published in Proceedings of Conferences and learned journals. Professional activities include foundation problems, deep excavations, nuclear power plants, slope stability, breakwaters, earthdams, tunneling and underground waste disposal. Awards: Thomas Telford Medal (ICE) in 1994 and 2007; Crampton Prize (ICE) in 2006; J. Torán Prize in 1995; N. Monturiol medal in 2000; Second Coulomb lecturer in 2003 and Eleventh Buchanan Lecturer, Texas A&M in 2003; Tenth Sowers Lecturer, GeorgiaTech, Atlanta in 2005. He is member of the Royal Academy of Engineering of Spain since 1995 and member of the Royal Academy of Sciences and Art of Barcelona since 2007. Núria M. Pinyol, born in 1978, got her degree in Civil Engineering (Ingeniero de Caminos, Canales y Puertos) in Barcelona in June 2004. At present she is a Researcher of the International Center for Numerical Methods in Engineering (CIMNE, Barcelona). She has worked on the development of constitutive models for bonded expansive soils and in the analysis and modeling of the geotechnical behaviour of earth and rockfill dams. One of her papers ("A review of Beliche dam") was awarded the Crampton Prize (ICE, UK) in 2006. Her main research interests are: behavior of unsaturated soils, expansive soils and rocks, hard soils and soft rocks, numerical analysis in Geomechanics, dams, slope stability and rapid slides.
Table of Contents
Preface; PART I. SETTLEMENTS; Chapter 1 Interaction Between Neighboring Structures: Mexico City Metropolitan Cathedral, Mexico; 1.1 Case Description; 1.1.1 Construction; 1.1.2 The history of settlements; 1.1.3 The problem; 1.1.4 The loading history; 1.2 The Theory; 1.2.1 Stresses; 1.2.2 Settlements; 1.2.3 Scenario 1: Silos A and B are built simultaneously; 1.2.4 Scenario 2: Silo B is built after Silo; 1.2.5 Scenario 3: Silo B is built after Silo A is removed; 1.2.6 Summary; 1.3 The Analysis; 1.3.1 Simplified model; 1.3.2 Settlements due to consolidation; 1.3.3 Settlements due to a drop in the groundwater levelp 1.3.4 Discussion; 1.4 Mitigation Measures; 1.5 Lessons Learned; 1.5.1 Loading history; 1.5.2 Distance between the neighboring structures; 1.5.3 Regional subsidence; 1.5.4 Do not mess with other people's gods!; References; Chapter 2 Unexpected Excessive Settlements: Kansai International Airport, Japan; 2.1 Case Description; 2.1.1 Introduction; 2.1.2 Construction; 2.1.3 The history of settlements; 2.1.4 The problem; 2.1.5 The observational method; 2.2 The One-Dimensional Theory; 2.2.1 Immediate settlement; 2.2.2 Settlement due to one-dimensional consolidation; 2.2.3 Secondary compression (creep) settlements; 2.2.4 Total settlements; 2.2.5 Inverse analysis of the settlement data; 2.3 The Analysis; 2.3.1 Simplified model; 2.3.2 The original prediction; 2.3.3 Correction for the initial settlement; 2.3.4 Correction for the length of the drainage path; 2.3.5 Correction for the secondary compression; 2.3.6 Total predicted displacement; 2.3.7 Discussion; 2.4 Mitigation Measures; 2.5 Lessons Learned; 2.5.1 High level of indeterminacy; 2.5.2 Immediate settlements; 2.5.3 Limited drainage; 2.5.4 Secondary compression; 2.5.5 The observational method; References; Chapter 3 Leaning Instability: The Leaning Tower of Pisa, Italy; 3.1 Case Description; 3.1.1 Construction; 3.1.2 The history of tilting; 3.1.3 The problem; 3.1.4 The leaning instability; 3.2 The Theory; 3.2.1 Model assumptions; 3.2.2 Equivalent foundations; 3.2.3 Overturning moment due to an incremental inclination; 3.2.4 Resisting moment mobilized by the foundations; 3.2.5 Spring coefficients; 3.2.6 Criteria for leaning instability; 3.2.7 Safety factors; 3.2.8 Bearing capacity; 3.2.9 Summary; 3.3 The Analysis; 3.3.1 Simplified model; 3.3.2 Bearing capacity; 3.3.3 Leaning instability; 3.3.4 Discussion; 3.4 Mitigation Measures; 3.5 Lessons Learned; 3.5.1 Leaning instability; 3.5.2 Failure; 3.5.3 Deep foundations; 3.5.4 Soil extraction; References; PART II. BEARING CAPACITY; Chapter 4 Bearing Capacity Failure: Transcona Grain Elevator, Canada; 4.1 Case Description; 4.1.1 Construction; 4.1.2 The failure; 4.1.3 The problem; 4.1.4 The bearing capacity failure; 4.2 The Theory; 4.2.1 Undrained bearing capacity formula; 4.2.2 Upper bound limit analysis; 4.2.3 Two-layer strata; 4.2.4 Summary; 4.3 The Analysis; 4.3.1 Model Parameters; 4.3.2 The Bearing Capacity Assumed in the Original Design; 4.3.3 A Conservative Estimate; 4.3.4 Two-Layer Strata; 4.3.5 Discussion; 4.4 Mitigation Measures; 4.4.1 Emptying of the Elevator; 4.4.2 Underpinning of the Work-house; 4.4.3 Straightening of the Bin-house; 4.4.4 Underpinning of the Bin-house; 4.5 Lessons Learned; 4.5.1 Site Investigation; 4.5.2 Field Load Tests; 4.5.3 Conservative Design;4.5.4 Upper Bound Limit Analysis; References; Chapter 5 Caisson Failure induced by Liquefaction: Barcelona Harbor, Spain; 5.1 Building a Caisson Dyke; 5.2 The Failure; 5.3 Soil Conditions; 5.3.1 Liquefaction; 5.4 Settlement Records and their Interpretation; 5.5 Safety during Caisson Sinking; 5.5.1 Caisson weight; 5.5.2 Bearing capacity; 5.5.3 An upper bound solution for a strip footing founded on clay with a linearly increasing strength with depth; 5.6 Caisson Consolidation. Increase in Soil Strength; 5.6.1 Stress increments under a strip footing and determination of excess pore pressures; 5.6.2 Stress increments; 5.6.3 Initial excess pore pressures; 5.6.4 Excess pore pressure dissipation; 5.6.5 Effective stresses and updated undrained strength; 5.7 Caisson Full Weight. Safety Factor against Failure and Additional Consolidation; 5.7.1 Caissons under full weight; 5.8 Caissons under Storm Loading; 5.8.1 Wave forces on caissons; 5.8.2 Static analysis. Safety factor; 5.8.3 Analysis of liquefaction; 5.9 Discussion; 5.10 Mitigation Measures; 5.10.1 Increasing the consolidation time under caisson weight; 5.10.2 Increasing the size of the granular berm; 5.10.3 Improving foundation soils; 5.10.4 Increasing caisson width; 5.10.4 After the failure 5.11 Lessons Learned; 5.11.1 Foundation on normally consolidated soft soil; 5.11.2 Strength changes due to caisson loading; 5.11.3 Undrained vs drained analysis; 5.11.4 Evolution of undrained strength; 5.11.5 Spatial distribution of cu controls mode of failure; 5.11.6 Type of loading and the failure mechanism; 5.11.7 Alternative definitions of safety factor; 5.11.8 Defining soil liquefaction condition; 5.11.9 Simplified analysis of liquefaction; 5.11.10 The flexibility of upper bound calculation; 5.11.11 Failure mechanism;5.12 Advanced Topics; Appendix 5.1; References; PART III. EXCAVATIONS; Chapter 6 Braced Excavation Collapse: Nicoll Highway, Singapore; 6.1 Case Description; 6.1.1 Design and construction; 6.1.2 The collapse; 6.1.3 The problem; 6.1.4 The undrained earth pressure analysis; 6.2 The Theory; 6.2.1 Long-term earth pressures; 6.2.2 Short-term earth pressures; 6.2.3 The undrained shear strength; 6.2.4 The Mohr Coulomb model; 6.2.5 The Modified Cam Clay model;6.2.6 The Original Cam Clay model; 6.2.7 Summary; 6.3 The Analysis; 6.3.1 The simplified model; 6.3.2 The long-term stability; 6.3.3 The short-term stability in the design; 6.3.4 Excavation progress and collapse; 6.3.5 The design error; 6.3.6 Discussion; 6.4 Mitigation Measures; 6.4.1 Immediate safety measures taken at the site; 6.4.2 Stages of Recovery; 6.4.3 Additional Safety Measures; 6.5 Lessons Learned; 6.5.1 Effective risk management; 6.5.2 Robustness of design; 6.5.3 Numerical modeling in geotechnical design; 6.5.4 Back analysis; References; Chapter 7 Tunnel Excavation Collapse: Borr