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Abstract Based on the understanding that rockburst induced by dynamic-loading is the result of structure instability of coal-rock，the experiments investigating the dynamic failure of coal-rock compound under one-dimensional static and dynamic loads were conducted using a modified split Hopkinson pressure bar(SHPB). The strength and fractal dimension of coal-rock compound were taken as the characteristic parameters and four typical levels of axial pre-compressive stresses were assigned for conducting the impact tests under different dynamic energies. The effects of dynamic and static loadings on the characteristic parameters were obtained. The results show that the coal-rock compounds with more cracks have higher resistance to the high-energy dynamic loadings and have the lower intensity of damage，which indicates that the measures of seam pressure relief would not only enhance the ability of coal-rock compound to withstand the high-energy dynamic load，but also reduce the intensity of rockburst. The structural characteristics of coal-rock not only enhances the ability of coal to withstand the high-energy dynamic load but also reduces the intensity of failure. Because of the very different time scales between the dynamic and static loadings，meanwhile，the structural characteristics weakens the effect of dynamic loading of high-energy on coal seam，and strengthens the impact of static load of high-energy.
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Received: 06 January 2014
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2014, Vol. 33 
