Effect of State parameter on Improvement of Shear Band Prediction in Granular Soils

The capability of sand constitutive models is remarkably improved by taking into account the effect of soil state in their formulations. In this study, it has been shown that considering the effect of soil state leads to better simulation of soil instability of shear banding type. To this aim, constitutive equations of a state dependent sand model are explained first. Consequently, the general conditions of instability and then, the special condition of instability with respect to the model formulation has been obtained. Using the result of a number of plane strain tests, the state dependent model predictions for shear band have been compared with experiment results. It has been shown that, predictions obtained from a similar model which neglect the effect of soil state are less favorable.