Bounding-surface hypoplasticity model for rockfill materials and its verification

Based on typical large-scale triaxial testing data for rockfills performed by Prof. Gao Lianshi, a concise procedure is presented for determining or/and calibrating the model parameters of bounding surface hypoplasticity constitutive law. Through a comparison between numerical simulations and test results for various static loading conditions, the validity of the constitutive model and its capability to reproduce complex behavior such as dilatancy and confining-pressure dependency of rockfill materials are verified. Furthermore, some realistic predictions of granular soils subjected to complex loading stress paths which are most likely to occur in practical rockfill dams are presented. These simulations are beneficial to gain a good understanding for properties of compression yielding and stress path dependency for rockfills under high confining pressures.