Investigation on the Fragmentation and Outburst Mechanism of Coal Sample with Pore Gas Using CDEM

In this paper, using the continuum-discontinuum element method (CDEM), fragmentation and outburst process of coal specimen are simulated, main factors affecting breaking explored. The results show that after seam is uncovered, generates obvious failure trend. Near coal-free surface, fracture blocks generate significant displacement, resulting in larger opening widths cracks. Coal deep cracks without an width. crack density with pore gas than those gas, it pores. However, early stage failure, separation ranges smaller numbers increase growth situ stress, ratio pressure. effect stress on block number (517–10,203) (7589–15,170) (5803–6836) a maximum size (0.0387–0.138 m) (0.0342–0.0733 (0.0454–0.0578 velocity range pressure (3.77–5.65 m/s); however, shows slow decrease ratio. (11.51–21.9 m/s) (4.52–5.23 This investigation beneficial to understand mechanisms coal–gas mining roadway excavation.