Abstract：Significant changes in fabric and accumulated plastic strain of saturated sand occur during the unloading-reloading process. Test results have shown that the plastic modulus in the first cycle is related to but different from that in the following loading cycles. To describe the deformation during the unloading-reloading process, a dilatancy internal variable accounting for the effect of fabric changes was introduced, and an of cyclic plastic modulus was proposed. A cyclic elasto-plastic boundary surface constitutive model of saturated sand was then established based on a previous monotonic model. The model is capable of simulating the cyclic stress-strain behavior of sand with different densities and confining pressures as well as under both drained and undrained conditions. The model has been validated against the cyclic test results of Ottaw sand, Fuji River sand and Toyoura sand with good agreement.
2017, Vol. 38 
