A gradation-dependent hypoplastic model for crushable sands

A gradation-dependent hypoplastic model is developed to capture the mechanical behaviours of crushable sands. First, a gradation evolution law is proposed to describe the variation of the grain size distribution (GSD) and the development of the extent of crushing during the loading process. Second, the family of CSLs under different gradations is formulated. Combining the developed CSL function and GSD evolution leads to well-modelling the unique critical state features of crushable sands. Subsequently, critical state features are incorporated into a well-established hypoplastic framework, such that the gradation-dependent hypoplastic model for crushable sands is developed. The accuracy and efficiency of the developed hypoplastic model in capturing the mechanical behaviours of crushable sands are validated against experimental counterparts.