Numerical modelling of nonlinear response of soil. Part 1: Constitutive model

In this contribution, on the basis of the hierarchical approach [Desai, C.S., 1980. A general basis for yield, failure and potential functions in plasticity. International Journal for Numerical and Analytical Methods in Geomechanics 4 (1980) 361-375], a constitutive model for the soil response in the elastoplastic range has been developed. The emphasis has been placed on presenting the particular model characteristics, simulation of soil hardening and softening response and the establishment of model nonassociativity. Based on standard available laboratory triaxial tests, a general procedure has been developed for determination of the material parameters of the constitutive model. All model parameters have been associated with quantities that can be determined from the experimental process ensuring thus the physical meaning of the parameters. A companion paper focuses on the applications of this constitutive model to investigate strain localization phenomena in sand, and the role of the fluid components on strain localization in 3D saturated sand specimen is addressed.