Parameters for an Elasto-Plasto-Damage Model for the StressStrain Behavior of Cohesive Soils

ABSTRACT: This article presents a constitutive model for cohesive soils that exhi-bits the post-peak strain-softening behavior. The model combines the elements of plasticity with damage mechanics to simulate the stressstrain behavior. The total strain increment is composed of an elasto-damage strain increment and a plastic strain increment. The post-peak stress drop is captured by the elasto-damage for-mulation, while the plasticity is superimposed beyond the elastic range. The elasto-damage strain increment is found using the elasto-damage formulation, while the plastic strain increment is found using either the DruckerPrager classical plasticity model or as a function of the damage strain. To calibrate this model, an experimental program was conducted on a cohesive soil at different densities and water contents. The various physical and mechanical properties of this soil were determined. Triaxial compression tests, unconfined compression test, and hydrostatic tests were per-formed, in order to obtain the model parameters at different conditions. These parameters were used to calibrate the model, which was coded in FORTRAN com-puter programs to simulate the stressstrain behavior of cohesive soils. The model was verified and found to be a good predictor of the response of cohesive soil for the selected stress path