土的统一硬化函数的构造

The hardening law in an elastoplastic constitutive model should be independent of the stress path for loading conditions. Based on the deformation behavior of soils along two orthogonal stress paths (i.e., constant mean stress shear path and isotropic compression path), a new hardening law, unified hardening law, is proposed to describe the shear contraction and dilatancy in an identical framework. Against Green's Formula and test data, we prove that the unified hardening law meets the requirement on the independence of loading path, theoretically and experimentally. The constitutive model developed by employing the unified hardening law is further verified by comparing it with the measured stress-strain relation of clay and sand under different loading paths.