THEORETICAL ANALYSIS AND FLAC3D SIMULATIONS ON ROCK CRACKS PROPAGATION CRITERION UNDER BLASTING LOADING

摘要

Considering the fracture mechanics, this paper analyzes the stress intensity factor under blasting loading and initial geostress. The rock crack's propagation criterion is introduced and the method of calculating the propagation zone is obtained. In order to prove its feasibility and rationality, one tailracc tunnel is analyzed by dynamical calculation of FLAC3D. The cracks propagation zone is illustrated. The results show the propagation zone is approximately 90- 100 times of the cylindrical charge, and are good coincidence with the results from the blasting experiments.