Elastoplastic soil constitutive laws generalized to partially saturated states

This paper deals with the plastic behaviour of partially saturated soils by modifying an existing model for fully saturated soils. The saturated soil model, formulated in the framework of generalized plasticity, considers volumetric as well as deviatoric strain hardening and takes account of the memory of past stress history and possible limit states. The generalization of the existing model to simulate the experimentally observed behaviour of partially saturated soils has been obtained by introducing Bishop's stress and suction as independent stress parameters and by modifying the hardening parameter and the yield condition to take into account the role of suction.