Modelling Pre- and Post-localisation Responses in Partially Saturated Soils

Classical models for partially saturated soils cannot correctly describe post-localisation behaviour. This is due to the use of assumptions on homogenous deformation, neglecting the strong localisation of deformation and saturation inside shear bands in post-localisation stage. This work addresses this challenge through the formulation and use of a constitutive model for partially saturated soils that possesses details at both macro and mesoscale of shear bands. Both behaviour and geometrical properties of shear bands (orientation, thickness) are considered in this model. Numerical examples based on experimental data in drained triaxial tests are used to demonstrate the promising features of the proposed model.