A bounding surface plasticity model for unsaturated soils accounting for the void ratio dependency of the water retention curve

The paper presents an advanced plasticity formulation for modelling partially saturated geomaterials based on the effective stress principle. The bounding surface plasticity framework is adopted for development of the proposed model. The bounding surface is assumed to undergo isotropic hardening due to increase in the volumetric strain and suction. A unique feature of the presented model is explicit incorporation of the influence of the soil density on the soil water retention curve and analytically correlating this dependency to the effective stress parameter without introducing additional material parameters. To validate the presented model, several experimental data including constant suction and wetting tests are simulated and the capability of the model to predict the experimental results is discussed.