Abstract: In order to study the blasting mechanism of coal contained gas further, we have analyzed the mechanism of blasting crack formation and propagation theoretically, and designed the blasting crack propagation experiment. The blasting crack propagation velocity and the blasting strain waves have been measured. The theoretical and experimental results show that the blasting crack propagation has three stages. One is rapid decay stage under blasting stress wave, the other one is slow decay stage and the last one is approximate uniform propagation stage under detonation gas and coal mine gas. The coal mine gas plays a positive role in the blasting crack propagation, and it can increase the crack propagation velocity in a small range in the later stage.

Key words: coal contained gas, blasting crack, propagation laws, experimental study