MODELING OF ELASTIC-ANISOTROPY DUE TO ONE-DIMENSIONAL PLASTIC CONSOLIDATION OF CLAYS

Experiments indicate that in one-dimensionally consolidated natural clays the elastic anisotropy is much stronger than the plastic strain anisotropy. Moreover, the elastic anisotropy appears to be dependent on the pre-consolidation strain. Coupled elasto-plastic constitutive law is shown to be able to simulate these anisotropy effects of natural clay deposits. In this law the elastic potential is not only a function of stress, but additionly of the plastic strain. The plastic strain comprises the geological process of pre-consolidation idealized as an one-dimensional plastic straining as well as a mechanically induced strain due to engineering activity. Calibration of the model and simulation of some stress paths are presented and related to the classical experimental results by Mitchell (1972).