Residual Strength of Clay and Clay-shales by Rotation Shear Tests


Book Description

The objectives of this investigation were to develop a rotation shear machine to measure the residual shear strength (constant shearing resistance at which material undergoes continuous deformation under a constant state of effective stress) of clays and clay-shales; investigate testing errors; and measure residual shear strengths of representative types of highly plastic clays and clay-shales. In the rotation shear test, torque is applied to the bottom of the specimen and two force transducers measure the couple necessary to maintain the upper half of the specimen stationary. Disc-shaped or annular specimens with thicknesses from 0.1 to 2.5 cm and outside diameters of 7.11 cm can be tested. Variations in residual shear strength were investigated for normally consolidated versus overconsolidated specimens, for specimens sheared at different rates of peripheral displacement, and for specimens prepared by several different remolding procedures. (Author Modified Abstract).




Engineering Properties of Clay Shales


Book Description

This report compares various laboratory procedures and equipment used for determining the residual strength of clay shales. The effects of testing apparatus, specimen type, normal load, and rate of displacement on the residual strength of various clay shales were evaluated by relations between residual strength and Atterberg limits, grain size, and mineralogy were examined. (Modified author abstract).




Laboratory Shear Strength of Soil


Book Description







Clay and Shale Slope Instability


Book Description

Ten papers address both empirical and analytical aspects of clay and shale slope instability. Among the topics discussed in detail are: limit equilibrium stability analysis, shear strength of clay and clayey colluvium, use of triaxial test data to evaluate viscoplastic slope movements, numerical modeling of pore pressure distribution in heterogeneous soils, rational analysis of rainfall and landslide movement patterns, the effects of hydrothermal alteration on slope stability, mudrock durability and stability considerations, and regional clay and shale slope stability problems in Italy.




Study of Clay Shale Slopes Along the Panama Canal


Book Description

Prepared for Office, Chief of Engineers, U.S. Army, Washington, D.C. and the Panama Canal Company







Slope Stability Engineering


Book Description

This collection of papers covers a wide range of relevant issues and aspects of slope stability engineering from both practical and scientific points of view from the Proceedings of the International Symposium on Slope Stability Engineering : Is--Shikoku'99 : Matsuyama, Shikoku, Japan, 8-11 November, 1999.




Shear Behavior of Composite Soils


Book Description

This book has the purpose of developing an understanding of the factors determining and influencing the shear behavior of soils, with emphasis on composite soils, as they are the most encountered materials in geological and geotechnical engineering in mountainous areas. This objective is reached by examining the soil compressibility, structure of shear zone and its evolution, and water content of shear zone and shear mode of soils together with analyses of the influences of intrinsic properties, e.g. Atterberg limits, particle size distribution, particle shape, and testing conditions, e.g. normal stress and shearing rate. An in-depth review is presented in an approximately chronological order and covers almost all the factors that are believed to influence the mechanical behavior of soils. The equipment and test techniques for shear strength of soils are detailed. The residual shear behavior of composite soil is investigated by means of a systematic laboratory testing program using a large ring shear apparatus and an intermediate direct shear box. The Fast Fourier Transform is employed for the first time to analyze the fluctuations of measured shearstress and discovers the close relationships with both intrinsic properties of soils and testing conditions. Although the book is aimed primarily at researchers in geological and geotechnical engineering, it contains material of interest to students of geology and soil science and also should be a useful reference for practicing engineers faced with composite soils.




Engineering Sites


Book Description

Developments in Geotechnical Engineering, Vol. 14B: Rockslides and Avalanches, 2: Engineering Sites focuses on initiatives to offer a foundation for studies of mass movement phenomena in the Western Hemisphere. The selection first takes a look at the contributions of Josef Stini to engineering, geology, and slope movement investigations, the concept of Karl Terzhagi on rockslides, and the contributions of Laurits Bjerrum to the mechanics of rockslides. Concerns cover stability of hard rock slopes, influence of geological details, relation between slide process and remedial treatment, water pressure in pores and fractures, slope creep, rockslides, and avalanches, and early warning of an impending slide. The publication then examines rock slope movements with hydroelectric power projects in Mexico, Bighorn Reservoir slides in Montana, U.S.A., rock avalanche and wave at Chungar, Peru, and wedge rockslides in Libby Dam and Lake Koocanusa in Montana. The text examines Hogarth Pit slope failure in Ontario, Canada, pit slope performance in shale in Wyoming U.S.A., Twin Buttes pit slope failure in Arizona, U.S.A., and the Prime Mine slope failure in Arizona, U.S.A. Discussions focus on stability analyses, description of slope failures, cause of failure, remedial actions, geotechnical properties of tertiary shales, and subsequent slope performance. The selection is a valuable source of data for researchers interested in rockslides and avalanches.