ABSTRACT
As an example of scale-dependent phenomena, experiments show that the post-peak behavior and the thickness of shear bands depend on particle size, on particle shape, and on the confining pressure. Work by the Grenoble group has shown that shear band thickness is roughly proportional to particle size, with observed thicknesses ranging from 7 times (for fine gravel) to 20 times (for fine sand) the mean, D50 particle diameter (Desrues & Viggiani 2004). Other studies consistently show that shear band thickness depends strongly on particles size and that the ratio of thickness to particle size lies within a narrow range for most granular materials (Bardet 1990; Vardoulakis 1998).
