Anisotropy of Undrained Shear Strength Induced by K0 Consolidation and Swelling in Cohesive Soils

Strength anisotropy should be introduced into stability analyses, because the shear direction differs at each sliding point. However, few experiments evaluating the effects of anisotropic consolidation on undrained shear strength have been available for practical construction problems. Therefore, torsional shear tests were conducted on specimens consolidated and swollen in different directions to evaluate the anisotropy of undrained shear strength. Furthermore, to treat two-dimensional problems, the tests were also performed under the plane strain condition, where no radial strain occurs. Results show that the anisotropy of the undrained shear strength is closely related to the differences between consolidation and shearing in terms of directions and stress conditions. Finally, slope stability analyses were conducted to demonstrate how the anisotropy of the undrained shear strength obtained from the experiments can be practically used in field analyses. (C) 2014 American Society of Civil Engineers.