Anisotropic hardening in the yield surface on constitutive models for unsaturated soils

Abstract

The mechanics of saturated soils evolved rapidly after Terzaghi established the principle of effective stress however the model established for these materials could not be applied for unsaturated soils. For that reason, in recent years, these materials have been investigated to establish the required equations to correctly model their behavior. There are different phenomena present on unsaturated soils such as: suction hardening, hydro-mechanical coupling and hysteresis of the retention curve. The purpose of this document is discussing the advantages and disadvantages of three different models including their parameters and their phenomenological considerations to establish the basis for a simpler and more practical model.