Use of hyper-elasticity in anisotropic clay plasticity models

In conventional elastic-plastic constitutive models for clays, elastic strainsare usually calculated by isotropic hypo-elastic models. however, this class of elasticityhas two major deciencies: (a) it ignores the inuence of shear stress-induced anisotropyand; (b) it does not conserve energy. another class of the elasticity theory, the socalledhyper-elasticity theory, is capable of eliminating both deciencies simultaneously.in this study, constitutive equations of a recently proposed elastic-plastic platform forclays named saniclay are generalized in order to enable it to consider the possibilityof the anisotropic response in the elastic domain. the generalized formulation allowsshear-volumetric coupling not existing in the basic platform. then, the elastic moduliobtained from a hyper-elastic model are implemented within the generalized saniclayformulation. the rened model predictions are directly compared with the experimentaldata of various clays. it is shown that more realistic stress paths are achieved from therened model.