SHEAR-BAND FORMATION IN SAND ACCORDING TO NONCOAXIAL PLASTICITY MODEL

The inadequacy of the ordinary flow and deformation theories of plasti city in explaining the experimental results on shear band formation in sand has led to the development of a consistent non-coaxial plasticit y theory. Using this theory, the theoretical predictions for shear ban d orientation and its onset are shown to agree well with experimental observations of biaxial tests. The decrease of shear band inclination angle with respect to the minor principal stress direction with increa sing confining pressure supports the hypothesis of the dependency of n on-coaxiality on confining pressure.