Numerical Modeling of Cyclic Triaxial Experiments for Granular Soil

In this study, cyclic triaxial tests under isotropic and anisotropic stress consolidation conditions were performed on Nuozhadu granular soil, and a constitutive model based on the Bouc-Wen model and endochronic theory was applied to investigate the dynamic stress-strain relationship and pore-water pressure of granular soils under cyclic triaxial stress states. In the isotropic stress consolidation condition, dynamic stress degradation occurred as a result of increased pore-water pressure and the reduction of effective stress. This paper presents the general validity of the model and its ability to describe several features of granular soil, including soil cyclic mobility, plastic strain accumulation, and stiffness and strength changes resulting from cyclic loading. Then, the equation of the model and key model parameters related to soil behavior, such as hysteresis and contractive and dilative behaviors, are further discussed. The proposed model was used to simulate the dynamic stress-strain relationship, effective stress path, and increased pore-water pressure under undrained conditions. The numerical results were found to have good agreement with the experimental curves.