Simulation of mechanical behaviour of Toyoura sand using Severn Trent constitutive model

In the numerical analyses of boundary value problems of geotechnical engineering it is often necessary to obtain realistic and accurate displacement fields. To this aim, constitutive models which reproduce accurately stress-strain behaviour of soils should be adopted. Severn-Trent (Gajo & Muir Wood, 1999a) is an advanced constitutive model for granular materials based on bounding surface and kinematic hardening plasticity. It is able to reproduce the main features of the mechanical behaviour of sands using a relatively simple mathematical formulation. In this paper, the capability of Severn-Trent model in reproducing the experimental data obtained in compression triaxial tests on Toyoura sand samples is presented and discussed. In order to obtain satisfactory model predictions also in undrained extension triaxial tests, the model was modified introducing two additional constitutive parameters which account for the inherent fabric anisotropy of the material. © 2010 Taylor & Francis Group, London.