Fragmentation Characteristic and Energy Dissipation of Coal under Impact Load

The catastrophic failure of coal under super-critical stresses and mining-induced disturbance is becoming one of major safety risks of underground mining. Research of the failure pattern of coal under impact load is helpful for understanding its burst behavior in order to mitigate the burst risk. To investigate the fragmentation characteristic and burst behavior of coal under impact load, drop weight tests of coal samples were conducted. This paper found that coal samples have high peak stress, pulverized fragmentation, and intensive burst energy under impact load. The fragments induced by the impact load have a relatively consistent distribution mode, which can be characterized by a fractal model. The burst energy accounts for more than 99% of the impact energy input while fragmentation energy only accounts for no more than 1%.