Two-Surface Soil Constitutive Model Calibration for Coarse Granular Materials

This paper presents a thorough calibration study for a recently developed constitutive model for coarse granular materials. The calibration was performed using true-triaxial experimental results for pea-gravels. Soil responses under various and complex stress paths were considered to verify the capability of the model to describe general constitutive behavior of soils. Stress paths used in the calibration process include: (1) monotonic stress paths in a deviatoric plane, (2) monotonic conventional triaxial compression (CTC) stress path, (3) cyclic simple shear (SS) stress path, and (3) circular cyclic stress path on a deviatoric plane with varying Lode angle and constant mean stress. Comparisons of the model simulations to the experimental results show that the model is capable of capturing the behavior of pea-gravel under monotonic and cyclic loading conditions.