Some aspects of fabric anisotropy of soil

An important feature controlling the elastic and plastic constitutive behaviour of a soil is the orientation of the particles. The overall behaviour of a soil on application of a load depends not only on its initial particle orientation, but also on its change during the loading. In this Paper a non-destructive, indirect method of measuring the change in anisotropy of particle orientation is described. The method is based on electrical conductivities measured in different directions. Results obtained on clay and sand specimens during one-dimensional consolidation are presented. The stress-strain behaviour of an assembly of two-dimensional cylindrical roads is simulated numerically, and the change in mechanical anisotropy is computed. The variation of mechanical anisotropy computed from numerical experiments is qualitatively in agreement with the variation of electrical anisotropy measured in the laboratory.