针对隧道或城市地下工程施工过程中重复爆破对围岩稳定性的影响开展研究.在不同轴压等级和冲击荷载作用下,利用带轴压装置的霍普金森压杆装置,对含横向孔洞的花岗岩试件进行单轴循环冲击试验研究,分析了花岗岩试件在动态循环冲击荷载下的力学性质和能量吸收规律特性.通过建立基于在能量耗散的岩石损伤度的判定准则,利用累计比能量来表征岩石在冲击过程中的损伤能量特性.研究结果表明:在施加轴压条件下,冲击试样的反射波形表征为“双峰”现象,并随损伤值的增加逐渐向“单峰”状态过渡.试件的动态峰值应力随冲击次数的增加先增大再降低,当轴压为21 MPa时抵抗外部冲击作用的能力最强,岩石的比能量随应变率的增加而逐渐增加且有较好的相关性.基于能量耗散建立的损伤值准则通过试验证明可以很好地表征损伤随冲击次数的关系,表现为缓慢增加-平稳增长-高速增长,且损伤值主要由最后一次冲击造成.试件冲击破坏形态在不同轴压水平作用下,均为轴向劈裂破坏模式,随应变速率的增大,试件吸能增多,单位破裂面逐渐增多,破碎程度加剧,碎块尺寸减小;当应变率较小时,破碎效果不明显;当应变率较大时,破碎效果显著.“,”This study investigated the effect of repeated blasting on the stability of surrounding rock during the construction of a tunnel or city underground engineering. The split Hopkinson pressure bar (SHPB) was used to carry out cyclic impact tests on granite samples, each having a circular hole, under different axial pressures, and the cumulative specific energy was proposed to characterize the damage characteristics of the rock during the cyclic impact. The mechanical properties and the energy absorbed by the granite samples under cyclic impact loads were analyzed. The results showed that under different axial pressures, the reflected waveform from the samples was characterized by“double-peak”phenomenon, which gradually changed to“single-peak”with the increase in damage value. The dynamic peak stress of the sample first increased and then decreased with an increase in impact times. The damage value criterion established based on the energy dissipation could well characterize the relationship between the damage and the number of impacts, which showed a slow increase, steady increase, and high-speed increase, and the damage value depended mainly on the last impact. Under the action of different axial pressures, all the failure modes of the samples were axial splitting failures. As the strain rate increased, with an increase in the dimension of the block, the sizes of the rock fragments decreased, and the fragmentation became more severe.