A hypoplastic model for cemented sand under monotonic and cyclic loading

In this study, a hypoplastic model is developed to describe the mechanical behaviors of cemented sand under both monotonic and cyclic loading conditions. A state variable is proposed to qualify the bonding strength. This variable is incorporated into the model to reflect the influence of cementation on the strength, stiffness, and dilatancy of sand. Bonding degradation is considered by allowing the state variable to evolve during deformation. A simple evolution is used with vanishing bonding strength for large deformation. The void ratio and friction angle in the critical state are related to the initial cementation. The model is subsequently extended to account for cyclic loading by incorporating the intergranular strain, fabric change effect, and semifluidized state. The capability of the model is demonstrated by simulating the behavior of cemented sand under both monotonic and cyclic loading conditions.