Study on Damage Model of Rock Based on Probability Method

In this paper, according to the volume strain of the rock and by referring to the probability method, the damage variable of the rock is defined and the 3D damage statistical constitutive equation is established. Through comparing the constitutive equation and the test data, the method for determining the equation parameters is given. The Research shows that with the variation of the unloading rate of the confining pressure on the rock, the value of parameters in the constitutive relation will change accordingly, and when the axial stress is small, the results are preferably matching the actual conditions, whereas when the axial stress is larger, the sigma(1) value under the same conditions will be lower than the actual one.