Affected by the disturbance of blasting activities, deformation instability and rock dynamic disasters are prone to occur in deep hard rock roadways. Thus, it is particularly necessary to understand the failure behavior of rocks and roadways under dynamic loads. In this study, a series of impact loading tests were carried out on sandstone samples with and without a circular cavity by a modified split Hopkinson pressure bar (SHPB) test system. The mechanical properties and energy evolution of the samples were systematically investigated, and the effect of cavity size was analyzed. The results showed that the presence of the cavity in the samples weakens the dynamic compressive strength by more than 10%, and the peak strain and brittleness are also reduced to varying degrees. Under dynamic loading, spalling cracks occur first on the roof and floor of the cavity, and then different numbers of shear cracks are formed on the sample diagonals. The eventual shear failure mode is the result of the connection of the shear cracks and the cavity. As the cavity radius increases, the dissipated energy density and fractal dimension both grow accordingly, leading to smaller and smaller rock fragments. The dynamic failure behavior of the circular cavity can be well explained based on the dynamic stress distribution law. Overall, this study can provide a reference for the study of the mechanism of rock burst in deep roadways.

受爆破作业的干扰，深部硬岩巷道易发生变形失稳和岩石动力灾害。因此，特别需要了解动载荷下岩石和巷道的破坏行为。在这项研究中，通过改进的霍普金森压力棒（SHPB）测试系统对带有或不带有圆形空腔的砂岩样品进行了一系列冲击载荷测试。系统地研究了样品的力学性能和能量演化，并分析了腔尺寸的影响。结果表明，样品中存在空腔会削弱动态抗压强度超过10％，并且峰值应变和脆性也会不同程度地降低。在动态加载下，散裂裂纹首先出现在型腔的顶部和底部，然后在样品对角线上形成不同数量的剪切裂纹。最终的剪切破坏模式是剪切裂纹与型腔连接的结果。随着腔半径的增加，耗散的能量密度和分形维数都相应增加，从而导致岩石碎片越来越小。基于动应力分布规律，可以很好地解释圆形空腔的动态破坏行为。总体而言，该研究可为深井巷道岩爆机理的研究提供参考。耗散的能量密度和分形维数都相应增加，导致岩石碎片越来越小。基于动应力分布规律，可以很好地解释圆形空腔的动态破坏行为。总体而言，该研究可为深部巷道岩爆机理的研究提供参考。耗散的能量密度和分形维数都相应增加，导致岩石碎片越来越小。基于动应力分布规律，可以很好地解释圆形空腔的动态破坏行为。总体而言，该研究可为深部巷道岩爆机理的研究提供参考。