THERMOMECHANICAL ANISOTROPIC MODEL FOR SOILS

 EDUARDO ROJAS and PAUL GARNICA

ABSTRACT An elastoplastic anisotropic model for soils is developed on the basis of thermomechanics and derived from two equations: the free energy and the dissipation functions representing the elastic and plastic behaviour of the material, respectively. Additionally, the dissipation function is integrated by two independent equations representing the flow rule and the plastic criteria. The model so derived presents a rotating yield surface, the rate of rotation depending on the induced anisotropy. The shape of the yield surface may be modified and depends on the value of a single parameter. Furthermore, the flow rule is of the non-associated type and can also be modified with a single parameter. Theoretical and experimental comparisons yield the conclusion that the model is able to adequately simulate the soil behaviour for different stress paths.

Key words: anisotropy, constitutive model, elastoplasticity, plastic potential, thermomechanics (IGC: E0/TI /D0)