Discussion on the integration of the complex hydromechanical coupling in a model adapted for unsaturated soils

These last fifty years, some new models were developed to describe the behaviour of unsaturated soils. The first ones (Bishop, 1963) were too close to models for saturated soils and failed to reproduce volumetric behaviour whereas the last ones as (Khalili et al. 2008) can incorporate the complex hysteretic behaviour of the retention curve but their parameters can be difficult to obtain.