Three-dimensional stress–strain and strength behavior of silt–clay transition soils

Abstract

The effect of silt content on the mechanical behavior of silt–clay transition soils under 3D stress conditions is presented. Undrained true triaxial tests with constant b values were performed on normally consolidated specimens of silt–clay transition soils created from the same base clay and nonplastic silt, however, with systematically varying gradations. With increasing amount of nonplastic silt, the cohesive soils exhibit less contractive tendencies, stiffer stress–strain response, and larger shear strength. The magnitude of intermediate principal stress, as indicated by the b value, also strongly influences the stress–strain relations, pore pressure behavior, and both total and effective failure surfaces. Although the transition soils exhibit overall clay-like behavior, more pronounced frictional characteristics, as indicated by the shapes of the failure and plastic potential surfaces, were exhibited with increasing silt content.