Abstract:Based on typical large2scale t riaxial 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 result s for various static loading conditions , the validity of the constitutive model and it s capability to reproduce complex behavior such as dilatancy and confining2pressure dependency of rockfill materials are verified. Furthermore , some realistic predictions of granular soils subjected to complex loading st ress 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 st ress path dependency for rockfills under high confining pressures.