Download or read book Strength Loss and Softening of Sensitive Clay Slopes written by Dong Soon Park and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Strength loss and strain softening/localization are important issues for sensitive clay slopes. There is a question that if the ground moves a fraction of a meter due to earthquake shaking, sensitive clays would be just as easily remolded and trigger a catastrophic failure. Two possible reasons why we expect different relationships between deformation and strength loss are: seismic (dynamic) failure mechanisms are different from gravity driven (static) failure mechanisms, and rate dependent shear strength hinders localization of deformations into distinct shear planes. In this dissertation, a literature review is performed to understand prior research on the behavior of sensitive clay slopes subjected to static and dynamic loading. Then, as a part of effort to simulate sensitive clay behavior with simplicity and accuracy, two constitutive models - rate-independent and rate-dependent sensitive clay models are developed. As an experimental approach, a construction technique to create sensitive clay in laboratory is also developed using a weak cement mix. In terms of repeatability and workability, physical modeling for artificially sensitive clay is valuable. The effects of sensitivity and earthquake intensity on the instability and deformation of slopes were studied using 12 centrifuge tests for cement treated clay slopes. Additional laboratory tests were performed to find material properties and static/dynamic behavior of artificially sensitive clays. Based on physical modeling and laboratory tests, shear band thickness is governed by sensitivity, strain rate, and test conditions. Regarding the behavior of sensitive clay slopes, two different counterbalancing effects exist together. One is the effect of strain softening and initial stiffness. Strain softening of sensitive clay tends to make soil deformation bigger, but higher stiffness of earlier stage of loading for sensitive clay hinders the amount of deformation. Therefore, the importance of strain level and corresponding mobilized strength should be highlighted when comparing the performance of sensitive and insensitive clay slopes. Only after remolding at large strains might we expect insensitive clays to perform better than weakly cemented sensitive clays. Sensitive clay slopes can suffer catastrophic failure if they are deformed enough to destroy their structure. The other counterbalancing effect exists between strain rate and strain softening. Strain rate effect may be an important parameter to affect how fast strain is localized. Faster strain rate (such as dynamic loading in centrifuge test) leads to higher strength. Then, the thickness of shear band tends to increase in terms of strain rate because larger shear bands develop smaller strain rates and smaller strengths. Hence, the rate effect hinders strain localization. However, because of strain softening, shear bands tend to localize as strain increases. Therefore, two competing effects exist together and there might be a rate-dependent optimal shear band thickness. Thus, it is crucial to account for the level of shear strain of concern. Depending on the shear strain level, mobilized strength can be different. Accordingly, mobilized strength is affected by the rate of softening and the rate of strain. Counteracting effects summarized above can explain different aspects of static and dynamic as well as laboratory and field scale shearing behavior of sensitive clay slopes.

Download or read book Landslides in Sensitive Clays written by Vikas Thakur and published by Springer. This book was released on 2017-05-23 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the most recent scientific research on the geological, geotechnical and geophysical aspects of slope failure in sensitive clays. Gathering contributions by international experts, it focuses on understanding the complete and practical spectrum of challenges presented by landslides in such complex materials. Based on sound and validated research results, the book also presents several recommendations that could be implemented in the guidelines or code-of-practice. These recommendations cover topics including the characterization and behavior of sensitive clays; the pre-failure, failure and post-failure stages of sensitive clays; mapping and identification methods; climate change; hazard assessment; and risk management. Sensitive clays are known for their potential for causing large landslides, which pose a serious risk to human lives, infrastructure, and surrounding ecosystems within their reach. This has been demonstrated by the recent catastrophic landslides in e.g. Sørum (2016), Skjeggestad (2015), Statland (2014), Byneset (2012), St-Jude (2010), Lyngen (2010) and Kattmarka (2009). The 2015 collapse of the Skjeggestad Bridge in Norway – which was due to a landslide in sensitive clay – alone costs millions of dollars in repairs. Recently, efforts are being made to increase society’s ability to cope with such landslide hazards. Geoscientists are now expected to provide input to the agencies responsible for landslide-risk preparedness. In other words, geoscientists’ role is not only to act as technologists to establish new theories, but also to go the extra mile to implement them in practice, so as to find meaningful solutions to geotechnical problems.

Download or read book Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions written by Francesco Silvestri and published by CRC Press. This book was released on 2019-07-19 with total page 8083 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions contains invited, keynote and theme lectures and regular papers presented at the 7th International Conference on Earthquake Geotechnical Engineering (Rome, Italy, 17-20 June 2019. The contributions deal with recent developments and advancements as well as case histories, field monitoring, experimental characterization, physical and analytical modelling, and applications related to the variety of environmental phenomena induced by earthquakes in soils and their effects on engineered systems interacting with them. The book is divided in the sections below: Invited papers Keynote papers Theme lectures Special Session on Large Scale Testing Special Session on Liquefact Projects Special Session on Lessons learned from recent earthquakes Special Session on the Central Italy earthquake Regular papers Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions provides a significant up-to-date collection of recent experiences and developments, and aims at engineers, geologists and seismologists, consultants, public and private contractors, local national and international authorities, and to all those involved in research and practice related to Earthquake Geotechnical Engineering.

Download or read book Landslides in Sensitive Clays written by Jean-Sébastien L'Heureux and published by Springer Science & Business Media. This book was released on 2013-09-17 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides in sensitive clays represent a major hazard in the northern countries of the world such as Canada, Finland, Norway, Russia, Sweden and in the US state of Alaska. Past and recent examples of catastrophic landslides at e.g. Saint-Jean-Vianney in 1971, Rissa in 1979, Finneidfjord in 1996 and Kattmarka in 2009 have illustrated the great mobility of the remolded sensitive clays and their hazardous retrogressive potential. These events call for a better understanding of landslide in sensitive clay terrain to assist authorities with state-of-the-art hazard assessment methods, risk management schemes, mitigation measures and planning. During the last decades the elevated awareness regarding slope movement in sensitive clays has led to major advances in mapping techniques and development of highly sophisticated geotechnical and geophysical investigation tools. Great advances in numerical techniques dealing with progressive failure and landslide kinematic have also lead to increase understanding and predictability of landslides in sensitive clays and their consequences. This volume consists of the latest scientific research by international experts dealing with geological, geotechnical and geophysical aspects of slope failure in sensitive clays and focuses on understanding the full spectrum of challenges presented by landslides in such brittle materials.

Download or read book ICPMG2014 Physical Modelling in Geotechnics written by Christophe Gaudin and published by CRC Press. This book was released on 2019-01-08 with total page 1366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 8th International Conference on Physical Modelling in Geotechnics (ICPMG2014) was organised by the Centre for Offshore Foundation Systems at the University of Western Australia under the auspices of the Technical Committee 104 for Physical Modelling in Geotechnics of the International Society of Soil Mechanics and Geotechnical Engineering. This quadrennial conference is the traditional focal point for the physical modelling community of academics, scientists and engineers to present and exchange the latest developments on a wide range of physical modelling aspects associated with geotechnical engineering. These proceedings, together with the seven previous proceedings dating from 1988, present an inestimable collection of the technical and scientific developments and breakthroughs established over the last 25 years. These proceedings include 10 keynote lectures from scientific leaders within the physical modelling community and 160 peer-reviewed papers from 26 countries. They are organised in 14 themes, presenting the latest developments in physical modelling technology, modelling techniques and sensors, through a wide range of soil-structure interaction problems, including shallow and deep foundations, offshore geotechnics, dams and embankments, excavations and retaining structures and slope stability. Fundamental aspects of earthquake engineering, geohazards, ground reinforcements and improvements, and soil properties and behaviour are also covered, demonstrating the increasing complexity of modelling arising from state-of-the-art technological developments and increased understanding of similitude principles. A special theme on education presents the latest developments in the use of physical modelling techniques for instructing undergraduate and postgraduate students in geotechnical engineering.

Download or read book Numerical Methods in Geotechnical Engineering written by Thomas Benz and published by CRC Press. This book was released on 2010-05-25 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical Methods in Geotechnical Engineering contains 153 scientific papers presented at the 7th European Conference on Numerical Methods in Geotechnical Engineering, NUMGE 2010, held at Norwegian University of Science and Technology (NTNU) in Trondheim, Norway, 2 4 June 2010.The contributions cover topics from emerging research to engineering pra

Download or read book Geotechnical Slope Analysis written by Robin Chowdhury and published by CRC Press. This book was released on 2009-11-18 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freshly updated and extended version of Slope Analysis (Chowdhury, Elsevier, 1978). This reference book gives a complete overview of the developments in slope engineering in the last 30 years. Its multi-disciplinary, critical approach and the chapters devoted to seismic effects and probabilistic approaches and reliability analyses, reflect the distinctive style of the original. Subjects discussed are: the understanding of slope performance, mechanisms of instability, requirements for modeling and analysis, and new techniques for observation and modeling. Special attention is paid to the relation with the increasing frequency and consequences of natural and man-made hazards. Strategies and methods for assessing landslide susceptibility, hazard and risk are also explored. Moreover, the relevance of geotechnical analysis of slopes in the context of climate change scenarios is discussed. All theory is supported by numerous examples. ''...A wonderful book on Slope Stability....recommended as a refernence book to those who are associated with the geotechnical engineering profession (undergraduates, post graduates and consulting engineers)...'' Prof. Devendra Narain Singh, Indian Inst. of Technology, Mumbai, India ''I have yet to see a book that excels the range and depth of Geotechnical Slope Analysis... I have failed to find a topic which is not covered and that makes the book almost a single window outlet for the whole range of readership from students to experts and from theoreticians to practicing engineers...'' Prof. R.K. Bhandari, New Delhi, India

Download or read book Landslides and Engineered Slopes Experience Theory and Practice written by Stefano Aversa and published by CRC Press. This book was released on 2018-04-17 with total page 2160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides and Engineered Slopes. Experience, Theory and Practice contains the invited lectures and all papers presented at the 12th International Symposium on Landslides, (Naples, Italy, 12-19 June 2016). The book aims to emphasize the relationship between landslides and other natural hazards. Hence, three of the main sessions focus on Volcanic-induced landslides, Earthquake-induced landslides and Weather-induced landslides respectively, while the fourth main session deals with Human-induced landslides. Some papers presented in a special session devoted to "Subareal and submarine landslide processes and hazard” and in a “Young Session” complete the books. Landslides and Engineered Slopes. Experience, Theory and Practice underlines the importance of the classic approach of modern science, which moves from experience to theory, as the basic instrument to study landslides. Experience is the key to understand the natural phenomena focusing on all the factors that play a major role. Theory is the instrument to manage the data provided by experience following a mathematical approach; this allows not only to clarify the nature and the deep causes of phenomena but mostly, to predict future and, if required, manage similar events. Practical benefits from the results of theory to protect people and man-made works. Landslides and Engineered Slopes. Experience, Theory and Practice is useful to scientists and practitioners working in the areas of rock and soil mechanics, geotechnical engineering, engineering geology and geology.

Download or read book Soil Strength and Slope Stability written by J. Michael Duncan and published by John Wiley & Sons. This book was released on 2014-09-22 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The definitive guide to the critical issue of slope stability and safety Soil Strength and Slope Stability, Second Edition presents the latest thinking and techniques in the assessment of natural and man-made slopes, and the factors that cause them to survive or crumble. Using clear, concise language and practical examples, the book explains the practical aspects of geotechnical engineering as applied to slopes and embankments. The new second edition includes a thorough discussion on the use of analysis software, providing the background to understand what the software is doing, along with several methods of manual analysis that allow readers to verify software results. The book also includes a new case study about Hurricane Katrina failures at 17th Street and London Avenue Canal, plus additional case studies that frame the principles and techniques described. Slope stability is a critical element of geotechnical engineering, involved in virtually every civil engineering project, especially highway development. Soil Strength and Slope Stability fills the gap in industry literature by providing practical information on the subject without including extraneous theory that may distract from the application. This balanced approach provides clear guidance for professionals in the field, while remaining comprehensive enough for use as a graduate-level text. Topics include: Mechanics of soil and limit equilibrium procedures Analyzing slope stability, rapid drawdown, and partial consolidation Safety, reliability, and stability analyses Reinforced slopes, stabilization, and repair The book also describes examples and causes of slope failure and stability conditions for analysis, and includes an appendix of slope stability charts. Given how vital slope stability is to public safety, a comprehensive resource for analysis and practical action is a valuable tool. Soil Strength and Slope Stability is the definitive guide to the subject, proving useful both in the classroom and in the field.

Download or read book Slope Analysis written by R Chowdury and published by Elsevier. This book was released on 2012-12-02 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slope Analysis summarizes the fundamental principles of slope analysis. It explores not only the similarities but also the differences in rock slopes and soil slopes, and it presents alternative methods of analysis, new concepts, and new approaches to analysis. The book introduces both natural and man-made slopes, the nature of soils and rocks, geomorphology, geology, and the aims of slope analysis. These topics are followed by chapters about stress and strain, shear strength of rock and soils, and progressive failure of slopes. This book also presents limit equilibrium methods I and II, which are the planar failure surfaces and slip surfaces of arbitrary shape, respectively. It also includes stress analysis and slope stability, natural slope analysis, and a brief review on plasticity and shear band analysis. Before presenting its conclusions, the book discusses special aspects of slope analysis, such as earthquake analysis, pseudo-static analysis, dynamic analysis, and anisotropy, in addition to Newmark's approach.

Download or read book Analytical Methods in Petroleum Upstream Applications written by Cesar Ovalles and published by CRC Press. This book was released on 2015-04-02 with total page 2054 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effective measurement of the composition and properties of petroleum is essential for its exploration, production, and refining; however, new technologies and methodologies are not adequately documented in much of the current literature. Analytical Methods in Petroleum Upstream Applications explores advances in the analytical methods and instrumentation that allow more accurate determination of the components, classes of compounds, properties, and features of petroleum and its fractions. Recognized experts explore a host of topics, including: A petroleum molecular composition continuity model as a context for other analytical measurements A modern modular sampling system for use in the lab or the process area to collect and control samples for subsequent analysis The importance of oil-in-water measurements and monitoring The chemical and physical properties of heavy oils, their fractions, and products from their upgrading Analytical measurements using gas chromatography and nuclear magnetic resonance (NMR) applications Asphaltene and heavy ends analysis Chemometrics and modeling approaches for understanding petroleum composition and properties to improve upstream, midstream, and downstream operations Due to the renaissance of gas and oil production in North America, interest has grown in analytical methods for a wide range of applications. The understanding provided in this text is designed to help chemists, geologists, and chemical and petroleum engineers make more accurate estimates of the crude value to specific refinery configurations, providing insight into optimum development and extraction schemes.

Download or read book Numerical Methods in Geotechnical Engineering written by Michael A. Hicks and published by CRC Press. This book was released on 2014-05-29 with total page 1368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical Methods in Geotechnical Engineering contains the proceedings of the 8th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE 2014, Delft, The Netherlands, 18-20 June 2014). It is the eighth in a series of conferences organised by the European Regional Technical Committee ERTC7 under the auspices of the International

Download or read book Ormen Lange an integrated study for safe field development in the Storegga submarine area written by A. Solheim and published by Newnes. This book was released on 2012-12-02 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Great effort has been undertaken to investigate potential geohazards in relation to the development of the Ormen Lange gas field offshore Mid-Norway. The field is located in the scar left after the giant, tsunami-generating Storegga Slide, which occurred roughly 8200 years ago, and the slide risk has consequently received particular focus. The studies have been multi-disciplinary in character, and have involved a number of companies, universities, and research institutions. The results of the project led to a significant advance in the understanding of the Storegga Slide in particular, and submarine slope instability in general, and played an important role in the approval of field development by Norwegian authorities. This book comprises 26 individual contributions representing the wide span of topics addressed in the project. The main scope is to provide a state-of-the-art report on geohazard investigations in a high latitude continental margin setting. Most of the data and results published in this book would not have reached beyond the confidential report stage unless the license partners of the Ormen Lange license had agreed that this information deserves a wider audience. - Multidisciplinary and covers most themes treated in slope stability studies prior to the field development phase - Provides a link between basic research and applied geohazard studies, with direct relevance for risk evaluation in relation to field development activities, such as pipeline design, drilling of wells, structure foundation etc. - A state-of-the-art report on geohazard investigations in a high latitude continental margin setting in relation to field development activities

Download or read book Guidelines for Open Pit Slope Design in Weak Rocks written by Derek Martin and published by CSIRO PUBLISHING. This book was released on 2018-01-10 with total page 791 pages. Available in PDF, EPUB and Kindle. Book excerpt: Weak rocks encountered in open pit mines cover a wide variety of materials, with properties ranging between soil and rock. As such, they can provide a significant challenge for the slope designer. For these materials, the mass strength can be the primary control in the design of the pit slopes, although structures can also play an important role. Because of the typically weak nature of the materials, groundwater and surface water can also have a controlling influence on stability. Guidelines for Open Pit Slope Design in Weak Rocks is a companion to Guidelines for Open Pit Slope Design, which was published in 2009 and dealt primarily with strong rocks. Both books were commissioned under the Large Open Pit (LOP) project, which is sponsored by major mining companies. These books provide summaries of the current state of practice for the design, implementation and assessment of slopes in open pits, with a view to meeting the requirements of safety, as well as the recovery of anticipated ore reserves. This book, which follows the general cycle of the slope design process for open pits, contains 12 chapters. These chapters were compiled and written by industry experts and contain a large number of case histories. The initial chapters address field data collection, the critical aspects of determining the strength of weak rocks, the role of groundwater in weak rock slope stability and slope design considerations, which can differ somewhat from those applied to strong rock. The subsequent chapters address the principal weak rock types that are encountered in open pit mines, including cemented colluvial sediments, weak sedimentary mudstone rocks, soft coals and chalk, weak limestone, saprolite, soft iron ores and other leached rocks, and hydrothermally altered rocks. A final chapter deals with design implementation aspects, including mine planning, monitoring, surface water control and closure of weak rock slopes. As with the other books in this series, Guidelines for Open Pit Slope Design in Weak Rocks provides guidance to practitioners involved in the design and implementation of open pit slopes, particularly geotechnical engineers, mining engineers, geologists and other personnel working at operating mines.

Download or read book Geotechnical Earthquake Engineering Second Edition written by Robert W. Day and published by McGraw Hill Professional. This book was released on 2012-08-20 with total page 693 pages. Available in PDF, EPUB and Kindle. Book excerpt: The latest methods for designing seismically sound structures Fully updated for the 2012 International Building Code, Geotechnical Earthquake Engineering Handbook, Second Edition discusses basic earthquake principles, common earthquake effects, and typical structural damage caused by seismic shaking. Earthquake computations for conditions commonly encountered by design engineers, such as liquefaction, settlement, bearing capacity, and slope stability, are included. Site improvement methods that can be used to mitigate the effects of earthquakes on structures are also described in this practical, comprehensive guide. Coverage includes: Basic earthquake principles Common earthquake effects Earthquake structural damage Site investigation for geotechnical earthquake engineering Liquefaction Earthquake-induced settlement Bearing capacity analyses for earthquakes Slope stability analyses for earthquakes Retaining wall analyses for earthquakes Other geotechnical earthquake engineering analyses Grading and other soil improvement methods Foundation alternatives to mitigate earthquake effects Earthquake provisions in building codes

Download or read book Numerical Modeling of Delayed and Progressive Failure in Stiff Clays with Two stage Softening Behaviour written by Zhifeng Zhan and published by . This book was released on 2013 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the laboratory, field and numerical results, the post-rupture strength defined firstly by Burland (1990) is verified and introduced in this thesis to describe the two-stage post-peak strain-softening characteristics of stiff clays. The first softening stage is induced by the loss of interbonding between particles, i.e. the cohesive component of strength at relatively small displacement and hence termed as cementation loss; while the second is due to the gradual realignment, i.e. reorientation of clay particles at large displacements and can be called as gradual frictional resistance loss. A generalised constitutive model is then established to simulate the two-stage softening characteristics of stiff clays by modifying the Mohr-Coulomb model. This model is formulated and then implemented into an explicit finite difference program FLAC. The new model is applied to simulate laboratory tests such as triaxial compression tests and direct shear box test to depict the new model. The numerical results demonstrate the capability and efficiency of the modified softening model to model the two-stage strain-softening behaviour of stiff clays. A series of analyses of delayed progressive failure of cut slopes in stiff clays have been performed using two-stage softening model incorporating post-rupture strength. The numerical results reproduce well the progressive failure process, position of failure surface and failure time, which proves further the validity of the new model. Meanwhile, parametric analyses are also carried out to demonstrate the general influence of post-rupture strength. The results demonstrate that the slope stability with the adoption of two-stage softening model is reduced compared with that using one-stage softening model due to the quicker cohesion reduction with deviatoric plastic strain in the first softening stage of two-stage softening model. Both post-rupture strength concept and two-stage softening model are applied to the modelling of a famous case¿ Aznalcóllar dam failure under both inhomogeneous and homogeneous hypotheses. The simulations reproduced well the failure of Aznalcóllar dam including the location and shape of the slip surface, the progressive failure course and the development of pore water pressure in terms of the developments of shear strain rate, shear strain increment, displacement, velocity and strength parameter softening. The mechanism of Aznalcóllar dam failure is deemed to be progressive failure mainly due to the softening of Guadalquivir blue clay. The developments of average stress ratio, average residual factor, average brittleness, average stress path, the distribution of shear stress and mobilised strength parameters along the slip surface confirm further the mechanism of progressive failure of Aznalcóllar dam with these values to be intermediate between peak and residual values during the failure course. The post-rupture state could be thought as the average one at initial failure. At final failure, most part of the slip surface is at residual state, especially along the horizontal part. The Aznalcóllar dam failure is sensitive to the softening rate. Larger rates will induce earlier failure and no failure will occur with slow softening rates. Only an appropriate setting of softening rates can cause failure at final phase under both inhomogeneous and homogeneous hypotheses. Finally, the post-rupture concept is introduced to derive analytical solutions to limit pressure, the stress, strain, and displacement fields for the cylindrical cavity expansion in stiff overconsolidated clay. The results of computational examples and the similarity between numerical solution and analytical one verify the reasonableness of the analytical solution to cavity expansion in stiff clays with two-stage softening characteristics.

Download or read book Foundation Design written by Allan Hodgkinson and published by Elsevier. This book was released on 2013-08-30 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foundation Design discusses fundamental concepts in the design of foundations. As with the author's previous work, the AJ Handbook of Building Structure, the emphasis is on practical matters and, while every architect may not aspire to more complicated designs, with the aid of this book he will be able to talk with more authority to his engineer. The book begins with an introduction to the properties rocks and soils, including sands and gravels, clays, and silts and peat. This is followed by discussions of the site investigation process, soil mechanics, and the principles of foundation design. Separate chapters cover foundation types (spread foundations and piles); foundation hazards and construction problems; and underpinning. Examples of foundation design are presented, such as simple bases, a column on the edge of a building, and examples of piling. The final two chapters discuss specifications for mass bases, reinforced pads, and trench foundations and pile caps; information to be given when inviting piling tenders; and the supervision of site works.