Download or read book Numerical Implementation and Modeling of Earthquake Induced Landslides for Slopes with Soft and Sensitive Clay Layers written by Naveel Islam and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake induced landslides pose a significant threat to many communities, environment and infrastructure. The potential damages could be severe in sensitive clay slope failures because the post-peak softening behaviour could cause retrogressive failure of soil blocks resulting in large-scale landslides. The failed soil blocks generally displace over a large distance during earthquake and post-quake stages. Therefore, upslope retrogression and downslope runout are two important phenomena need to be studied for better understanding of risks associated with landslides in sensitive clays. The traditional limit equilibrium methods, commonly used in slope stability analysis, cannot model retrogressive failure or deformation of slopes. The present study concentrates on development of large deformation finite element (FE) models using a Coupled Eulerian- Lagrangian (CEL) approach to simulate the failure of soft and sensitive clay slopes triggered by earthquakes. Analyses are performed for pseudostatic and dynamic loading conditions modeling the undrained behaviour of clay as elasto-plastic material with and without post-peak degradation of shear strength. A nonlinear post-peak strength degradation model as a function of accumulated plastic shear strain is implemented in FE analysis. In addition to CEL, FE analyses are performed using Lagrangian-based FE techniques to show the advantages of CEL to simulate large landslides. The CEL approach can successfully simulate the formation of shear bands (zone of accumulated shear strains), type of failure commonly observed after earthquake, upslope retrogression and downslope runout for varying geometry and soil properties.
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 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 Numerical Study of Large Deformation Retrogressive Landslides in Sensitive Clay Triggered by Toe Erosion and Earthquake written by Chen Wang and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides in sensitive clays represent a severe geohazard in eastern Canada and Scandinavia. Triggered by various factors, such as toe erosion, earthquake, and human activities, a sensitive clay landslide can affect a large area and cause damage to infrastructure. The evaluation of risk associated with sensitive clay landslides is an important but challenging task because the failure mechanisms are not well understood. Different types of landslide (e.g. flowslide, monolithic slide, and spread) occur through significantly different failure processes that affect both retrogression and run-out. Full-scale modeling of such large-scale landslides is not practically feasible. On the other hand, real-time monitoring of the failure in the field is not possible. Therefore, the characteristics of the landslides are generally evaluated by comparing post-slide field investigations with available information on the site before the landslide. Numerical modeling could be an alternative tool to obtain further insights into the failure mechanisms. The failure occurs by progressive formation of shear bands where extremely large plastic shear strain generates, and the failed soil displaces over a large distance. Consequently, the methods commonly used for slope stability analysis, such as limit equilibrium (LE) methods and Lagrangian-based finite element (FE) methods, cannot be used to model the whole process of a sensitive clay landslide. The main objective of the present study is to analyze the factors affecting the failure pattern and extent of sensitive clay landslides triggered by toe erosion and seismic loading. A large deformation finite element (LDFE) method based on Eulerian approach is used to simulate the triggering of the landslide, subsequent failure of soil blocks and run-out of the debris. The landslide generally occurs rapidly in a matter of few minutes; therefore, the simulation is performed for the undrained condition. The strain-softening behavior of sensitive clay is defined as a function of plastic shear displacement that reduces the undrained shear strength to a very low value at a large strain. A strain-rate dependent undrained shear strength model is used, which can model the behavior of soil and remolded clay that flows at a high speed as a fluid-like material. The formation of a slope generally occurs due to the removal of the materials in drained condition. Moreover, groundwater seepage might dominate the failure of a slope. Numerical simulation techniques for the Eulerian based LDFE method are developed to simulate in-situ effective stresses, which can be used for the cases of widely varying earth pressure coefficient at rest, even greater than unity. Based on the thermal-hydraulic analogy, a numerical modeling technique is developed for seepage analysis. The above-mentioned methods can successfully simulate the initial stress condition in the soil that affects the failure mechanisms significantly. Many failures of sensitive clay slope are initiated by toe erosion. Conducting LDFE simulations, the potential conditions required for a flowslide and a spread are identified. The type and extent (retrogression and run-out) of a landslide depend on a combination of several factors related to geometry and soil properties. A single parameter, such as stability number, remolded shear strength, liquidity index or remolded energy, may not always be suitable to categorize failure type. Increasing lateral earth pressure coefficient at-rest shows a trend of occurring spreads, while a low remolded shear strength and favorable conditions for rapid displacement of debris result in flowslides. The comparison of LDFE simulations and post-slide investigations of the 2010 Saint-Jude landslide show that the present numerical simulations can explain several features of the landslide, including the effects of seepage and an opposite riverbank on progressive failure. Finally, pseudostatic and dynamic analyses are performed using the developed LDFE method to study the progressive formation of failure planes in clay slopes subjected to earthquake loading. The LDFE modeling in Eulerian approach can simulate the large displacement of the failed soil blocks, considering the reduction of shear strength due to strain-softening.
Download or read book Landslides written by John J. Clague and published by Cambridge University Press. This book was released on 2012-08-23 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides have geological causes but can be triggered by natural processes (rainfall, snowmelt, erosion and earthquakes) or by human actions such as agriculture and construction. Research aimed at better understanding slope stability and failure has accelerated in recent years, accompanied by basic field research and numerical modeling of slope failure processes, mechanisms of debris movement, and landslide causes and triggers. Written by seventy-five world-leading researchers and practitioners, this book provides a state-of-the-art summary of landslide science. It features both field geology and engineering approaches, as well as modeling of slope failure and run-out using a variety of numerical codes. It is illustrated with international case studies integrating geological, geotechnical and remote sensing studies, and includes recent slope investigations in North America, Europe and Asia. This is an essential reference for researchers and graduate students in geomorphology, engineering geology, geotechnical engineering and geophysics, as well as professionals in natural hazard analysis.
Download or read book Understanding and Reducing Landslide Disaster Risk written by Binod Tiwari and published by Springer Nature. This book was released on 2020-12-22 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a part of ICL new book series “ICL Contribution to Landslide Disaster Risk Reduction” founded in 2019. Peer-reviewed papers submitted to the Fifth World Landslide Forum were published in six volumes of this book series. This book contains the followings: • Five keynote lectures • Recent development in physical modeling of landslides • Recent development in numerical modeling of landslides • Recent development in soil and rock testing techniques, application and analysis methods • Recent advancements in the methods of slope stability and deformation analyses • Recent development in disaster risk assessment Prof. Binod Tiwari is a Vice President of the International Consortium on Landslides (ICL). He is the Associate Vice President for research and sponsored project and Professor of civil and environmental engineering at the California State University, Fullerton, California, USA. Prof. Kyoji Sassa is the Founding President and the Secretary-General of the International Consortium on Landslides (ICL). He has been the Editor-in-Chief of International Journal Landslides since its foundation in 2004. Prof. Peter Bobrowsky is the President of the International Consortium on Landslides. He is a Senior Scientist of Geological Survey of Canada, Ottawa, Canada. Prof. Kaoru Takara is the Executive Director of the International Consortium on Landslides. He is a Professor and Dean of Graduate School of Advanced Integrated Studies (GSAIS) in Human Survivability (Shishu-Kan), Kyoto University.
Download or read book Coseismic Landslides written by Ikuo Towhata and published by Springer Nature. This book was released on 2022-11-04 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the result of an elaborate project initiated by the Joint Technical Committee (JTC-1) of 1) the International Society for Soil Mechanics and Geotechnical Engineering, 2) the International Association for Engineering Geology and the Environment, 3) the International Society for Rock Mechanics, and 4) the International Geotextile Society, with the focus on natural slopes and landslides. The framework of the book sets out the steps, based on recent disaster experiences in the twenty-first century, leading to the assessment of earthquake-induced landslide hazards. It contains: 1) important cases of landslides triggered by earthquakes around the world; 2) investigation into the characteristics of ground motion site response; 3) methods to determine landslide susceptibility and triggering thresholds and their comparative study; and 4) commentary on the production of earthquake-induced landslide hazard maps. All the contents are the result of the latest research on related areas. The book is a valuable resource for researchers, designers, consultants, academicians, government officials, and all others who are involved in the mitigation of coseismic landslides. The book contributes toward the development of a new chapter in disaster prevention and mitigation of landslides induced by earthquakes.
Download or read book Analytical and Numerical Modeling of Progressive Failure of Onshore and Offshore Slopes with Sensitive Clay Layer written by Rajib Dey and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides in both onshore and offshore environments are always a potential hazard and a great threat to many communities and infrastructure. There are some similarities and differences between failure mechanisms and potential causes of failure of slopes in these two environments. Large landslides in both environments are generally progressive in nature. This becomes more pronounced when the slide occurs in sensitive clays, generally assumed under undrained condition. Post-peak softening of sensitive clays is considered as one of the main reasons for pronounced progressive failure. Sensitive clays found in both environments show nonlinear post-peak strain softening behavior at large strain/displacement during undrained loading. Post-slide investigations show that failure patterns of many large-scale submarine landslides through marine clays could be very similar to onshore landslides through sensitive clays as encountered in Eastern Canada and Scandinavia (e.g. translational progressive slide, and spreads). As onshore slope failures in sensitive clays are better documented than submarine landslides in marine clays, information on onshore sensitive clays available in the literature can be utilized as the basis to model both submarine and subaerial landslides in sensitive clays. The main focus of the present study is to model slope failure through weak sensitive clay layers under undrained conditions. A nonlinear mathematical model for post-peak degradation of undrained shear strength of sensitive clay, applicable to small to large-strains, is proposed in this study based on available experimental results. The slope failure mechanisms are examined using the concept of shear band propagation. Various factors have been identified in the past that could trigger a large-scale slope failure in both environments. Among them, the effects of toe erosion, surcharge loading, and strength reduction in a section of a weak layer are considered in this study. In a marine environment, strength reduction in a section of a weak layer in an offshore slope might result in initiation and propagation of a shear band in both upslope and downslope directions at the same time. By incorporating a nonlinear post-peak softening model, an analytical solution is developed to examine a possible mechanism of failure of mild submarine slopes containing a weak zone of low shear strength. In comparison, due to toe erosion, a shear band formation could be initiated and propagated upward (inward) from the river bank which could lead to a spread type failure forming horsts and grabens. Upslope surcharge loading (e.g. the placement of fill) could also generate shear bands that might propagate down towards the river bank. Numerical modeling of these types of slope failure is considered as a large deformation problem. Finite element (FE) models in Lagrangian framework cannot model the complete process of these slides, as significant mesh distortion occurs. Coupled Eulerian Lagrangian (CEL), a finite element approach in Abaqus FE software is used in this study to model these progressive failures of slopes. A nonlinear strain softening model for undrained shear strength of sensitive clays is incorporated in the FE simulation. Upward progressive failure leading to spread due to toe erosion, downward progressive failure due to a construction load in the upslope area, and combined effects of upward and downward propagation of shear bands on stability of a river bank slope have been simulated in this study. Simulations are also carried out to model submarine landslides due to the existence of a weak layer. The FE simulated results and failure patterns of ground surface or seabed are compared with the slide morphology presented in the literature. The main advantages of the present FE modeling are: (i) extremely large strains in the shear bands can be successfully simulated without numerical issues, (ii) a prior definition of shearing zones with special mesh and/or element type is not required to capture extreme strains in the shear bands, and (iii) the FE program automatically identifies the location of critical shear band formation and direction of propagation.
Download or read book Recent Advances in Modeling Landslides and Debris Flows written by Wei Wu and published by Springer. This book was released on 2014-09-12 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides and debris flows belong to the most dangerous natural hazards in many parts of the world. Despite intensive research, these events continue to result in human suffering, property losses, and environmental degradation every year. Better understanding of the mechanisms and processes of landslides and debris flows will help make reliable predictions, develop mitigation strategies and reduce vulnerability of infrastructure. This book presents contributions to the workshop on Recent Developments in the Analysis, Monitoring and Forecast of Landslides and Debris Flow, in Vienna, Austria, September 9, 2013. The contributions cover a broad spectrum of topics from material behavior, physical modelling over numerical simulation to applications and case studies. The workshop is a joint event of three research projects funded by the European Commission within the 7th Framework Program: MUMOLADE (Multiscale modelling of landslides and debris flows, www.mumolade.com), REVENUES (Numerical Analysis of Slopes with Vegetations, http://www.revenues-eu.com) and HYDRODRIL (Integrated Risk Assessment of Hydrologically-Driven Landslides, www.boku.ac.at/igt/).
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 3375 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 Earthquake Induced Landslides written by Yingbin Zhang and published by Springer. This book was released on 2017-07-15 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book sheds new light on improved methods for the study of the initiation and run-out of earthquake-induced landslides. It includes an initiation study method that considers tension-shear failure mechanism; an improved, rigorous, dynamic sliding-block method based on dynamic critical acceleration; and a run-out analysis of earthquake-induced landslides that takes account of the trampoline effect, all of which add to the accuracy and accessibility of landslide study. The book includes abundant illustrations, figures and tables, making it a valuable resource for those looking for practical landslide research tools.
Download or read book Coupled DEM CFD Analyses of Landslide Induced Debris Flows written by Tao Zhao and published by Springer. This book was released on 2017-05-22 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects the latest research results in computer modelling of landslide-induced debris flows. The book establishes an understanding of the initiation and propagation mechanisms of landslides by means of numerical simulations, so that mitigation strategies to reduce the long-term losses from landslide hazards can be devised. In this context, the book employs the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) to investigate the mechanical and hydraulic behaviour of granular materials involved in landslides – an approach that yields meaningful insights into the flow mechanisms, concerning e.g. the mobilization of sediments, the generation and dissipation of excess pore water pressures, and the evolution of effective stresses. As such, the book provides valuable information, useful methods and robust numerical tools that can be successfully applied in the field of debris flow research.
Download or read book Landslides Theory Practice and Modelling written by S.P. Pradhan and published by Springer. This book was released on 2018-06-28 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, with contributions from international landslide experts, presents in-depth knowledge of theories, practices, and modern numerical techniques for landslide analysis. Landslides are a reoccurring problem across the world and need to be properly studied for their mitigation and control. Due to increased natural and anthropogenic activities, chances of landslide occurrence and associated hazards have increased. The book focuses on landslide dynamics, mechanisms and processes along with hazard mitigation using geo-engineering, structural, geophysical and numerical tools. The book contains a wealth of the latest information on all aspects of theory, practices and modelling tools and techniques involved in prediction, prevention, monitoring, mitigation and risk analysis of landslide hazards. This book will bring the reader up to date on the latest trends in landslide studies and will help planners, engineers, scientists and researchers working on landslide engineering.
Download or read book Hydro mechanical Analysis of Rainfall Induced Landslides written by Lizhou Wu and published by Springer Nature. This book was released on 2020-01-14 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most landslides are triggered by rainfall. In previous studies, slope stability is often evaluated based on the infiltration analysis. Hydro-mechanical coupling is significant to rainfall-caused landslide evolution. This book covers theoretical models of unsaturated infiltration, and provides hydro-mechanical models for rainfall-induced landslides. The influences of rainfall patterns, boundary conditions, layered structures, and SWCC hysteresis on the coupled unsaturated infiltration and deformation are discussed. Laboratory testing of rainfall-induced landslides is performed to study the developing process of landslide upon rainfall infiltration. The results provide a better understanding of rainfall-induced landslides.
Download or read book Rainfall Induced Soil Slope Failure written by Lulu Zhang and published by CRC Press. This book was released on 2018-09-03 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rainfall-induced landslides are common around the world. With global climate change, their frequency is increasing and the consequences are becoming greater. Previous studies assess them mostly from the perspective of a single discipline—correlating landslides with rainstorms, geomorphology and hydrology in order to establish a threshold prediction value for rainfall-induced landslides; analyzing the slope’s stability using a geomechanical approach; or assessing the risk from field records. Rainfall Induced Soil Slope Failure: Stability Analysis and Probabilistic Assessment integrates probabilistic approaches with the geotechnical modeling of slope failures under rainfall conditions with unsaturated soil. It covers theoretical models of rainfall infiltration and stability analysis, reliability analysis based on coupled hydro-mechanical modelling, stability of slopes with cracks, gravels and spatial heterogenous soils, and probabilistic model calibration based on measurement. It focuses on the uncertainties involved with rainfall-induced landslides and presents state-of-the art techniques and methods which characterize the uncertainties and quantify the probabilities and risk of rainfall-induced landslide hazards. Additionally, the authors cover: The failure mechanisms of rainfall-induced slope failure Commonly used infiltration and stability methods The infiltration and stability of natural soil slopes with cracks and colluvium materials Stability evaluation methods based on probabilistic approaches The effect of spatial variability on unsaturated soil slopes and more
Download or read book Seismically induced Rock slope Failure written by Lorne Arnold and published by . This book was released on 2016 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismically-induced rock-slope failures have caused the deaths of tens of thousands of people and economic losses in the billions over the last century. They are among the most common, dangerous, and still today, least understood of all seismic hazards. This research aims to further the understanding of seismically-induced rock-slope failure by studying the initiation and growth of fractures in rock-slopes during seismic loading. The Bonded Particle Model, which is commonly used in the static simulation of complex rock mechanics applications, is extended for use in fully-dynamic 2-dimensional simulation of rock-slopes. Using this model, the influence of ground motion characteristics and structural geology on the behavior and performance of rock-slopes during earthquakes is explored. The results show that dynamic stresses that develop within rock-slopes make the face of the slope particularly susceptible to damage. As damage accumulates in rock-slopes during dynamic loading, slopes can soften and become more sensitive to lower frequency input. Loading amplitude and frequency have a substantial impact on the seismic performance of rock-slopes, and this impact is highly dependent on the internal geologic structure of the rock-slope. The model results are consistent with observations of several historical earthquake-induced rock-slope failure events, and provide insight into the fundamental mechanisms behind seismically-induced rock-slope failures.
Download or read book Landslides and Engineered Slopes From the Past to the Future Two Volumes CD ROM written by Zuyu Chen and published by CRC Press. This book was released on 2008-06-11 with total page 2170 pages. Available in PDF, EPUB and Kindle. Book excerpt: 270 Expert contributions on aspects of landslide hazards, encompassing geological modeling and soil and rock mechanics, landslide processes, causes and effects, and damage avoidance and limitation strategies. Reference source for academics and professionals in geo-mechanical and geo-technical engineering, and others involved with research, des
