This dissertation, "Failure of Saturated Sandy Soils Due to Increase in Pore Water Pressure" by Sainulabdeen Mohamed, Junaideen, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled FAILURE OF SATURATED SANDY SOILS DUE TO INCREASE IN PORE WATER PRESSURE Submitted by Sainulabdeen Mohamed Junaideen for the degree of Doctor of Philosophy at The University of Hong Kong in January 2005 Most slope failures are attributable to an increase in pore water pressure during or following periods of intense rainfall. These failures are induced by reduction of effective confining stress whilst shear stress remains nearly constant, as opposed to the failures caused by increasing shear stress in standard laboratory tests. Although the significance of the different stress paths has been recognized, studies of soil behaviour in constant shear stress path, which closely represents conditions during a rise in pore water pressure, have been scarce. Furthermore, past studies suggest that the steady state line is not unique and the volume change tendency of soils is stress path-dependent. These findings make it difficult to predict the behaviour of soils during a rise in pore water pressure. Nevertheless, there is an urgent need to study such behaviour as rainfall-induced slope failures occur in various types of soils and occasionally turn into debris flows, posing a serious risk to both life and property. The principal objectives of this study were to characterize the soil behaviour during a rise in pore water pressure and to examine existing theories in respect of the instability of soils. A comprehensive testing program, which included load-controlled constant shear stress path tests and standard strain rate-controlled undrained tests, was conducted on completely decomposed granites. Specimens prepared at various densities were used for the tests. A fast data-acquisition system was utilized so that readings during rapid deformations could also be recorded. The study's findings showed that the steady state line was reasonably unique for a given soil and that the volume change tendency was not path-dependent. The steady state concept could be used to explain soil behaviour during a rise in pore water pressure; and the difference between the current void ratio and the void ratio at the steady state at the current stress level could be used to characterize soil behaviour. Instability of the soils occurs at higher stress ratios in the constant shear stress path than in the undrained loading stress path. To define the instability state due to a rise in pore water pressure, the post-peak portion of undrained effective stress paths is of very limited use for this type of soil. Conversely, using the constant shear test results, the instability state can be adequately defined for soils of various densities. Furthermore, the concept of collapse surface can be extended to define the instability state of soils of various densities due to undrained loading. DOI: 10.5353/th_b3070854 Subjects: Shear strength of soils Slopes (Soil mechanics) Sandy soils - Testing

Sand, clay and rock have to be excavated for a variety of purposes, such as dredging, trenching, mining (including deep sea mining), drilling, tunnel boring and many other applications. Many excavations take place on dry land, but they are also frequently required in completely saturated conditions, and the methods necessary to accomplish them consequently vary widely. This book provides an overview of cutting theories. It begins with a generic model, valid for all types of soil (sand, clay and rock), and continues with the specifics of dry sand, water-saturated sand, clay, atmospheric rock and hyperbaric rock. Small blade angles and large blade angles are discussed for each soil type, and for each case considered the equations/model for cutting forces, power and specific energy are given. With models verified by laboratory research, principally from the Delft University of Technology, and data from other recognized sources, this book will prove an invaluable reference for anybody whose work involves major excavations of any kind.

Cohesive sediment, or mud, is encountered in most water bodies throughout the world. Often mud is a valuable resource, synonymous with fertile land, enriching the natural environment and used as an important building material. Yet mud also hinders navigation and consequently, dredging operations have been carried out since ancient times to safeguard navigation. Unfortunately, many mud deposits are now contaminated, endangering the eco-system and increasing the costs of dredging operations. The transport and fate of mud in the environment are still poorly understood and the need for basic research remains. This text contains the proceedings of the INTERCOH-2000 conference on progress in cohesive sediment research. It was the sixth in a series of conferences initially started by Professor Ashish Mehta in 1984 as a "Workshop on Cohesive Sediment Dynamics with Special Reference to the Processes in Estuaries". During these conferences the character of the first workshop has always been maintained, that is, small scale and dedicated to the physical and engineering aspects of cohesive sediments, without parallel sessions, but with ample time for discussions during and after the presentations, and followed by a book of proceedings containing thoroughly reviewed papers. INTERCOH-2000 was integrated with the final workshop of the COSINUS project. This project was carried out as a part of the European MAST-3 programme, and almost all European cohesive sediment workers were involved. INTERCOH-2000 focused on the behaviour and modelling of concentrated benthic suspensions, i.e. high-concentrated near-bed suspensions of cohesive sediment. Special attention was paid to: sediment - turbulence interaction; flocculation and settling velocity; high-concentrated mud suspensions; processes in the bed - consolidation; processes on the bed - erosion; field observations on mud dynamics; instrumentation; and numerical modelling.

This book presents a one-stop reference to the empirical correlations used extensively in geotechnical engineering. Empirical correlations play a key role in geotechnical engineering designs and analysis. Laboratory and in situ testing of soils can add significant cost to a civil engineering project. By using appropriate empirical correlations, it is possible to derive many design parameters, thus limiting our reliance on these soil tests. The authors have decades of experience in geotechnical engineering, as professional engineers or researchers. The objective of this book is to present a critical evaluation of a wide range of empirical correlations reported in the literature, along with typical values of soil parameters, in the light of their experience and knowledge. This book will be a one-stop-shop for the practising professionals, geotechnical researchers and academics looking for specific correlations for estimating certain geotechnical parameters. The empirical correlations in the forms of equations and charts and typical values are collated from extensive literature review, and from the authors' database.

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

Unsaturated Soil Mechanics is the first book to provide a comprehensive introduction to the fundamental principles of unsaturated soil mechanics. * Offers extensive sample problems with an accompanying solutions manual. * Brings together the rapid advances in research in unsaturated soil mechanics in one focused volume. * Covers advances in effective stress and suction and hydraulic conductivity measurement.

The definitive guide to unsaturated soil— from the world's experts on the subject This book builds upon and substantially updates Fredlund and Rahardjo's publication, Soil Mechanics for Unsaturated Soils, the current standard in the field of unsaturated soils. It provides readers with more thorough coverage of the state of the art of unsaturated soil behavior and better reflects the manner in which practical unsaturated soil engineering problems are solved. Retaining the fundamental physics of unsaturated soil behavior presented in the earlier book, this new publication places greater emphasis on the importance of the "soil-water characteristic curve" in solving practical engineering problems, as well as the quantification of thermal and moisture boundary conditions based on the use of weather data. Topics covered include: Theory to Practice of Unsaturated Soil Mechanics Nature and Phase Properties of Unsaturated Soil State Variables for Unsaturated Soils Measurement and Estimation of State Variables Soil-Water Characteristic Curves for Unsaturated Soils Ground Surface Moisture Flux Boundary Conditions Theory of Water Flow through Unsaturated Soils Solving Saturated/Unsaturated Water Flow Problems Air Flow through Unsaturated Soils Heat Flow Analysis for Unsaturated Soils Shear Strength of Unsaturated Soils Shear Strength Applications in Plastic and Limit Equilibrium Stress-Deformation Analysis for Unsaturated Soils Solving Stress-Deformation Problems with Unsaturated Soils Compressibility and Pore Pressure Parameters Consolidation and Swelling Processes in Unsaturated Soils Unsaturated Soil Mechanics in Engineering Practice is essential reading for geotechnical engineers, civil engineers, and undergraduate- and graduate-level civil engineering students with a focus on soil mechanics.

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.