Practical nonlinear constitutive model for rockfill materials with application to rockfill dam

In this paper, a nonlinear constitutive model for rockfill materials is proposed to account for the coupling influence of the mean effective stress p and the deviatoric stress q on the deformation of rockfill materials. In the model, the stress-dilatancy relationship derived from the microstructural changes of granular materials is adopted, and the strength nonlinearity of rockfill materials is considered by using a logarithmic relationship between the peak friction angle and the mean effective stress. The SMP criterion is incorporated into the model to consider the influence of the intermediate principal stress. The good performance of the proposed model is demonstrated through modelling triaxial tests on rockfill materials from a rockfill dam. In addition, the FEM simulated deformation of a real CFRD using the proposed model agrees well with the monitored data.