Study on Hardening Parameters and Elastoplastic Constitutive Model of Rockfill Materials

Abstract

An elastoplastic constitutive model is proposed to account for stress loading effects based on triaxial test results of granite rockfill materials. The model utilizes an extended yield function to flexibly control the yield surface shape, distinguishing between loading, unloading, and neutral loading conditions. A non-associated flow rule is implemented, incorporating a critical dilatancy stress ratio into the dilatancy equation to capture particle breakage behavior. The model primarily focuses on the formulation of a stress-path-independent hardening parameter based on the dilatancy equation. A total of 12 model parameters are introduced, all of which can be determined from two conventional laboratory geotechnical tests. Finally, the validity of the proposed model is verified through triaxial test results of various rockfill materials.