On Comparing Simple Shear and Triaxial Test Results

Abstract

It is indisputable that nonuniformities of stresses and strains exist in soils tested not only in the simple shear apparatus (SSA) but in the triaxial apparatus as well. These nonuniformities alone cannot explain the differences observed from the results of soils tests in the SSA and the triaxial apparatus. Regardless of nonuniformities, the behavior of soils in the SSA and triaxial apparatus should differ from one another because they were designed to impose different stress conditions on the soil samples. This study shows that the often-ignored intermediate principal stresses in the SSA play a significant role in the response of soils tested under plane strain conditions. The stress path followed by sand in the two apparatus differ significantly when the intermediate principal stresses are taken into account.