Reanalysis of simple shear soil testing

Abstract

Simple shear devices are used fairly extensively in soil mechanics research, lately especially in connection with cyclic testing. This presentation starts out by extending existing isotropic, elastic analyses of stresses and strains in the simple shear test. The effects of partial differential boundary slippage at the interface between the soil specimen and the top and bottom caps of the apparatus are analyzed. A comparison is made between constant volume and truly undrained simple shear tests.Because there is a coupling of shear and normal strains in soils, both may result from either shear or normal stresses, and vice versa. Therefore, an applied simple shear state of strain will not in general produce a simple shear state of stress in a soil sample, and it is shown analytically and experimentally that significant changes in lateral stresses do occur in simple shear tests. Such patterns of behavior are thereafter incorporated in the interpretation of cyclic loading simple shear tests on sand.