Abstract：Based on random distribution of interior defect in rock，a statistical damage constitutive model for rock is developed by using the continuous strength theory and statistical theory. Failure criterion of rock，as the distribution variable of the micro-unit strength in the constitutive model，greatly affects stress-strain curve and the equivalent elastic modulus of rock，and it must be chosen carefully for specific rock. By using back analysis method，the statistical distribution parameters in the constitutive model are solved. The proposed model can consider the effect of stress states and reflect the behavior in which the complete stress-strain curve of rock varies with stress-strain state. Comparison of the proposed model and experimental results shows that the proposed model is verified and can be applied in practical engineering.
