Numerical Simulation and Analysis of Blast-induced Cracks in Hard Coal Body

According to dynamic mechanical characteristics and relevant blasting parameters of hard coal body in the third mining area of Antai mine,the column charge explosion process of single hole is simulated by LS-DYNA programs.The range and formation time of smash district and crack area are obtained by analyzing the effect of blasting stress wave on the mechanical properties of coal and propagation process of blasting crackle.It is found that the radius of smash district in hard coal body is approximately 3.8 times of the charge radius,while the radius of crack area is approximately 51 times of the charge radius.