Damage characteristic of rock sample with circular defect based on the distinct element and moment tensor methods
Baowen Hu1,2, Changhong Li2
1School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing, China
2State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing, China
Based on the distinct element and moment tensor theory, the damage process and mechanism of rock sample with circular hole were researched. The crack evolution patterns corresponding to the laboratory test showed that there were mainly four stages. Firstly, the microcracks were randomly distributed in the rock sample. Secondly, the larger primary cracks are formed around top of circular hole with the increasing of microcracks. Then, more microcracks were localized near the boundary of circular hole, which formed the competition of several possible sets of fractures. Finally, the rupture zone was formed along one of crack zones. The size effect of circular hole showed that there would take on different rupture forms with increasing of diameter. Meanwhile, for better probing into damage mechanism, the acoustic emission (AE) algorithm based on moment tensor theory was implanted into the whole loading process. The AE magnitudes of all parts of rock sample were shown in AE contour maps, and these contour maps showed that the formations of rupture zone were contributed by different stress or energy levels.