Abstract
Considering the heterogeneity of rock, cohesion for elements throughout the rock is supposed to follow a three parameter Weibull distribution, and the cohesion decreases to zero when the element fails according to Mohr–Coulomb criterion. A damage evolution equation for rock undergoing compression is derived based on the statistic theory and shear force equilibrium equation of the shear failure plane. The derived damage evolution equation is reasonable because it considers the failed elements ability of resisting pressure and frictional shear force. A statistic damage constitutive model is then established and verified by comparing the simulated finite element method results with laboratory triaxial testing results. Numerical results show that the developed model simulates the peak and residual strength of triaxial tests very well.
This research work is financially supported by the National Natural Science Foundation of China (grant no. 50720135906 and no. 40772184).