Geotechnical failures, specially the catastrophic ones, are a stimulus to improve current understanding of phenomena and procedures and tools for analysis and prediction. This unconventional approach to geomechanics is the essence of this book. In general, soil mechanics and geotechnical textbooks describe first the concepts and theoretical developments and then apply them to interpret or solve a particular applications. This book follows a different course. The case (a failure) is first described and then an explanation is sought. This requires a set of steps which can be summarized as follows: Identify the nature of the problem, develop a dedicated and specific formulation of the case, based on established basic concepts. In general, no single existing theory or procedure is available to solve the case at hand, provide a solution within an acceptable degree of complexity, extract the fundamental aspects of the problem and highlight its relevance. The cases selected have been grouped into three main topics: Landslides, Embankments and Dams and Dynamics of Failures. Cases selected (Vaiont, Aznalcollar, Brattas-St. Moritz) are unique and illustrate a number of relevant and to some extent controversial issues which are of wide interest, without claiming exhaustive treatment of the subject. The book teaches how to build the necessary models to understand the failures. Well established soil mechanics concepts are the necessary background. But the cases analyzed require in general a step ahead which is specific for the case analyzed. Balance and equilibrium equations are often required as a starting point. They are formulated at different scales, which are selected having in mind the abstract representation of each case. Various chapters illustrate also the coupled nature (flow-deformation-temperature) of geotechnical problems and the need to properly address these complexities in some cases. In fact, temperature effects, a subject often neglected in conventional analyses, are necessary to explain some catastrophic landslides (Vaiont). In some of the chapters, specific calculation tools, included in well known and widely available programs (Excel, Maple...) have been used. Details of the ad hoc programs developed have also been included in Appendices to help the readers to follow the details of the calculation. Finite element methods have not been used. In the landslides analyzed (Vaiont and Brattas-St. Moritz) currently available commercial programs are of limited utility. In the remaining cases the analysis performed provides a sufficient insight and interpretation of field behaviour. Chapters include also a short description of the changes in the original design and the mitigation measures which could have prevented the failure. Also, a summary section of lessons learned is provided in all chapters. Finally, selected topics and more advanced reading are suggested. This book is associated with a Master/Doctorate course being offered at the Department of Geotechnical Engineering and Geosciences of UPC, Barcelona. Potential readers therefore include Graduate and Master students, faculty and professionals in the fields of Civil and Geotechnical Engineering.

The main goal of this introductory text 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 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 author's experience. They have been organized into three main topics: Settlement, Bearing Capacity and Excavations. They cover a significant proportion of every day's activity 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.

Geotechnical failures, specially the catastrophic ones, are a stimulus to improve current understanding of phenomena and procedures and tools for analysis and prediction.

This unconventional approach to geomechanics is the essence of this book. In general, soil mechanics and geotechnical textbooks describe first the concepts and theoretical developments and then apply them to interpret or solve a particular applications. This book follows a different course. The case (a failure) is first described and then an explanation is sought. This requires a set of steps which can be summarized as follows: Identify the nature of the problem, develop a dedicated and specific formulation of the case, based on established basic concepts. In general, no single existing theory or procedure is available to solve the case at hand, provide a solution within an acceptable degree of complexity, extract the fundamental aspects of the problem and highlight its relevance.

The cases selected have been grouped into three main topics: Landslides, Embankments and Dams and Dynamics of Failures. Cases selected (Vaiont, Aznalcollar, Brattas-St. Moritz) are unique and illustrate a number of relevant and to some extent controversial issues which are of wide interest, without claiming exhaustive treatment of the subject.

The book teaches how to build the necessary models to understand the failures. Well established soil mechanics concepts are the necessary background. But the cases analyzed require in general a step ahead which is specific for the case analyzed. Balance and equilibrium equations are often required as a starting point. They are formulated at different scales, which are selected having in mind the abstract representation of each case.

Various chapters illustrate also the coupled nature (flow-deformation-temperature) of geotechnical problems and the need to properly address these complexities in some cases. In fact, temperature effects, a subject often neglected in conventional analyses, are necessary to explain some catastrophic landslides (Vaiont). In some of the chapters, specific calculation tools, included in well known and widely available programs (Excel, Maple ) have been used. Details of the ad hoc programs developed have also been included in Appendices to help the readers to follow the details of the calculation.

Finite element methods have not been used. In the landslides analyzed (Vaiont and Brattas-St. Moritz) currently available commercial programs are of limited utility. In the remaining cases the analysis performed provides a sufficient insight and interpretation of field behaviour.

Chapters include also a short description of the changes in the original design and the mitigation measures which could have prevented the failure. Also, a summary section of lessons learned is provided in all chapters. Finally, selected topics and more advanced reading are suggested.

This book is associated with a Master/Doctorate course being offered at the Department of Geotechnical Engineering and Geosciences of UPC, Barcelona. Potential readers therefore include Graduate and Master students, faculty and professionals in the fields of Civil and Geotechnical Engineering."

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.