AN ELASTO-PLASTIC SUBLOADING SURFACE MODEL FOR CLAY WITH ISOTROPIC AND KINEMATIC MIXED HARDENING PARAMETERS

A subloading surface constitutive model for clay is developed along a general theory proposed by Hashiguchi (1986). The novel part concerns introduction of a mixed (i.e. composed of isotropic and deviatoric part) kinematic hardening parameter describing translation of the normalyield surface in the stress space to account for the induced anisotropy of clayey soils. The model is judged by comparisons with the element test data obtained for complex plane strain paths with up to two sharp bends.