Experimental study on the shock failure feature of coal triggered by uniaxial dynamic loading

The uniaxial static and dynamic loading experiments wereexecuted by using MTS-C64. 106 press. Mechani-cal properties,rock burst performance,AE feature,dynamic failure feature and fractal dimension feature of coal mass were investigated by combining the monitoring results of PIC-2 and high-speed camera. Along with the increase of dy-namic loading strain rate,the coal mass strength increased by following a logarithmic function,and the rock burst dan-ger also increased. The disturbed energy input rate,the amount of AE and strike inccidents varied as “increase slowly-increase rapidly-increase suddenly”. Failure form of coal mass experienced a “ shear failure-vertical splitting failure-burst failure”. It showed a quadratic relationship between the fractal dimension of fragments and dynamic loading strain rate. There must be a dynamic loading strain rate,which achieves the strongest rock burst,and it is 2. 8×10-3 s-1 according to the experiment results.