A constitutive model for granular soils

A simple constitutive model is presented to describe the mechanical behaviors of granular soils in a large stress range. A novel normal compression line (NCL) is first expressed by introducing a limit void ratio (e_L) in the double logarithmic scale. Subsequently, a state parameter (ξ) is defined to quantify the current state of granular soils, and a unified hardening parameter (H) that is a function of the state parameter (ξ) is developed to govern the hardening process of the drop-shaped yield surface. Combining with flow rule, a constitutive model for granular soils is proposed. Finally, the comparison between the predictions and the test results of Cambria sand and Coarse-grained material indicates that the model is able to describe the mechanical behaviors of granular soils in a large stress range.