Parameters for an Elasto-Plasto-Damage Model for the Stress-Strain Behavior of Dense Sand

Abstract

This article presents a constitutive model for dense sand that exhibits a post-peak strain-softening behavior. This model combines elements of plasticity with damage mechanics to simulate the stress—strain behavior. The post-peak stress drop is captured by the elasto-damage formulation, while the plasticity is superimposed beyond the elastic range. The total strain increment is composed of an elasto-damage strain increment and a plastic strain increment. The elasto-damage strain increment is found using the elasto-damage formulation, while the plastic strain increment is found using either the Drucker—Prager classical plasticity model or as a function of the damage strain. To calibrate this model, an experimental program was conducted on dense sand at different relative densities. The various physical and mechanical properties of the sand were determined. Both triaxial compression tests and hydrostatic tests were performed under different confining pressures, in order to obtain the model parameters at various conditions. These parameters were used to calibrate the model, which was coded in FORTRAN computer programs to simulate the stress—strain behavior of dense sand. The model was verified and found to be a good predictor of the response of dense sand for the selected stress path.