On a simple critical state model for sand

The paper presents a so-called hypoplastic constitutive model with critical state for the three dimensional non-linear stress-strain and dilatant volume change behaviour of sand. The model is based on non-linear tensorial functions and is substantially different from the elastoplastic models. The concepts such as yield surface, plastic potential and flow rule are not used in developing the model. The effect of both the void ratio and of the stress level is accounted for by integrating the critical state into the model.