Introducing Two Effective Modifications for Pastor-Zienkiewicz Model for Improvement of Dynamic Simulation Capability of Granular Soils

Two effective modifications were introduced for Pastor-Zienkiewicz (PZ) model to improve the prediction of dynamic behavior of granular soils. The first modification was implementation of degradation effect for dense granular soils under cyclic loading, and the second was improvement of ratcheting effect for granular soils under cyclic loading. Three cyclic triaxial tests and three cyclic plane strain test were used to validate the introduced modifications. Predictions of stress versus strain for both of modifications were satisfactory. However, predictions of volumetric strain for the second modification were better than those of the first modification.