Six-parameter constitutive model of sand with physical state changes

Most constitutive models for sands use the relative density as an index, so that a sand with different initial densities is treated as different materials. These models result in multiple sets of model parameters for a single material. This paper presents a simple constitutive model with only six material parameters based on the state parameter concept. The model takes into account the physical state changes due to changes in the relative density and the effective pressure to represent the constitutive response of sand during drained shearing over a wide range of densities and pressures using a unique set of parameters. Simulations with this constitutive model agree well with triaxial drained test results.