A new critical strain energy release rate failure criterion for anisotropic rock under high confining pressure

To research the influences of confining pressure on critical strain energy release rate (Gc) and energy transformation of anisotropic intact rocks, by combining a new modified Hoek-Brown failure criterion for anisotropic rock under high confining pressure (M-HB-HC) with the energy release rate failure criterion, the new critical strain energy release rate failure criterion is established. Triaxial compression tests for marble and sandstone samples with different bedding plane dip angles under different confining pressures have been performed. The study shows that Gc depends on both the bedding plane dip angle alpha and confining pressures, and the variation of Gc with the dip angle under low confining pressure is not evident, but is significant at the high confining pressure. Under the same confining pressure, the value of bedding marble's Gc is greater than that of bedding sandstone. By comparing prediction results of several failure criteria with that of the proposed failure criterion and the experimental data, we found that the prediction of the new critical strain energy release rate failure criterion has better accuracy. The proposed failure criterion is applicable for different type of anisotropic intact rocks. This paper only researches the transverse isotropic case of the anisotropic rock. The other anisotropic will be studied in the future.(c) 2023 Elsevier Ltd. All rights reserved.