Research into the effects of micromechanical parameters on creep failure in brittle rocks

Subcritical crack growth plays an important role for long-term creep failure in brittle rock. Microcrack angle is a significant parameter in theoretical analysis. However, it is difficult to be obtained from test or theory. Based on micromechanical creep theory of brittle rock which is established by using of relationship between micromechanical crack growth and macroscopic strain, effects of the value of microcrack angle on creep property of brittle rock with given initial damage are investigated in this paper. Based on the theoretical model and testing results, an exact method to determine the reasonable value of microcrack angle in a given rock specimen is suggested. Using this determined crack angle, further creep analysis of brittle rock is carried out, and all numerical results are graphically presented. As verification, the comparison of irreversible strain between theoretical and experimental results shows a good agreement.