Modelling the hydro-mechanical behaviour of GMZ bentonite

This paper proposes a hydro-mechanical model of GMZ bentonite, based on the considerable amount of experimental research that has been developed recently. The model uses a double porosity approach based on the framework provided by the Barcelona Expansive Model to describe the deformability of the bentonite. A state surface was used to define its microstructural behaviour, based on the high-suction range data from water retention curves. The intra-aggregate (microstructural) and inter-aggregate (macrostructural) water contents were differentiated. The proposal was satisfactorily applied to simulate several constant stress swelling tests and swelling pressure tests, improving the confidence in the model. The use of this model has allowed not only reproduction of the experimental data but also improvement of our knowledge of GMZ bentonite behaviour.