On the volumetric deformation of reconstituted soils

Abstract

This paper reviews the phenomenon of volumetric hardening, which is a common feature of the mechanical behaviour of many geo-materials. Three different material idealizations have been proposed to describe this hardening, and the paper contains the corresponding mathematical formulation. These idealizations vary in their complexity and hence their ability to capture different aspects of real material behaviour. Any of the three postulates can be implemented into most constitutive models. As a demonstration of their capabilities, the postulates have been implemented into the well-known modified Cam Clay model, and computations are made with the resulting new constitutive models. It is seen that the new models can successfully represent important features of soil behaviour such as plastic yielding associated with loading inside the current virgin yield surface, the loosening or densifying of granular soils caused by shearing, and the accumulation of both volumetric and distortional deformation caused by repeated drained loading over a large number of cycles. Copyright © 2000 John Wiley & Sons, Ltd.