Hydro-mechanical hypoplastic models for unsaturated soils under isotropic stress conditions

The current work presents two hypoplastic models to predict the hydraulic and mechanical behavior of the unsaturated soils. The hydraulic model is capable to reproduce the observed hysteretic behavior for the drying and wetting processes and incorporates the void ratio dependence. The mechanical model is written in terms of the Bishop effective stress and is limited only to isotropic states. It incorporates a normal consolidation line that depends on the degree of saturation. Both models were developed under the hypoplastic framework and therefore are capable to simulate the observed behavior without defining a yield surface. Simulations of some experiments performed with Pearl clay suggest that the models accurately predict its hydro-mechanical behavior.