f Strength parameter of clay in slope

Abstract: Stress-states in the field under loading condition are not unidirectional, rather the magnitude of stresses differs from one element to another. The principal stresses directions, and hence the principal strains directions, in soil mass under loaded condition rotates along the potential failure surface (e.g., slope, embankment and bearing capacity failure, etc.). Therefore, the geotechnical problems are three-dimensional in slope for which anisotropy in the design parameters should be properly accounted for all possible stress paths. When an undrained failure occurs in a slope of clay, the shear strength mobilised on a failure surface may vary with the orientation of the surface either as a result of anisotropy of the clay or as a result of reorientation of principal stresses. In order to show how these two factors, hereafter termed as anisotropy, influence the undrained strength characteristics of clay, experimental investigations were done by static laboratory element tests (such as triaxial, direct shear and unconfined compression tests).