Elastoplastic Simulation of Stress–Strain Response Considering the Cyclic Degradation of Saturated Clay

A modified anisotropic bounding surface model is developed to simulate the stress–strain response of saturated clay under cyclic loading. In this study, kinematic hardening variables are introduced into the equation for a rotational bounding surface, and an anisotropic bounding surface equation is established by strict mathematical derivation from the isotropic and kinematic hardening rules. To characterize the cyclic degeneration behavior of soil stiffness, the accumulated deviatoric plastic strain is incorporated into the plastic modulus interpolation function. This modified model is then validated by comparison to results of undrained cyclic triaxial tests of isotropic and anisotropic consolidated clay samples from the literature. The results show that the performance of the modified model is an improvement over the original model for simulating the hysteresis, accumulation, and cyclic degeneration of stress–strain response.