In recent years, the depth, intensity and complexity of coal mining in China has continued to increase. Meanwhile rockburst disasters, especially fault-slip bursts, have become even more severe. Research on precursor characteristics and early warning methods need to be in-depth, as rock burst disasters severely restrict the safety production of coal mines. Stress waves (dynamic loading) caused by the rupture of the roof of overlying rock layers, or the slipping activity of faults act on coal and rock masses, can easily cause the sudden instability of coal and rock masses and induce rockburst disasters in a high in situ stress environment. Therefore, this article is about a study of fracture characteristics of coal mass and its acoustic emission (AE) signal response under dynamic loading. The results show that the dynamic strength presented a “double peak” pattern. It rapidly dripped after two crests appear, and the second crest was higher than the first crest. With increase in bullet velocity (and applied axial static load conditions), the dynamic strength–strain curve shifted upward gradually. The difference between the two peaks was relatively stable. The coal sample with cracks and pores was damaged significantly at the first wave crest, the damage area was concentrated mainly around the ring of the sample. The proportions of the meta-instability stage in total process time increased with increase in impact velocity applied on the samples, which ranged from 3.17 to 5.94%. The axial static load did not show a significant role affecting proportion of the meta-instability phase in whole process time. The AE peak count and energy increased linearly with increase in impact velocity, while they decreased with increase in axial static load. When employing a same impact velocity, the difference between the two peaks increased with increase in axial static load. Because the first wave crest appeared when the coal body ruptured, the accurate rupture time of the coal body can be monitored by the AE count and energy. The paper sheds some light on exploring the fractural evolution process of coal and rock masses under dynamic loading, as well as being a reference basis for the evolutional mechanism of rockburst under a far-field fluctuational load condition. The research results are helpful to further improve the prediction accuracy and control of rock burst in coal mines.

近年来，我国煤炭开采的深度、强度和复杂程度不断提高。与此同时，岩爆灾害，尤其是断层滑爆，变得更加严重。岩爆灾害严重制约煤矿安全生产，前兆特征和预警方法研究需要深入研究。上覆岩层顶板破裂或断层滑移活动引起的应力波（动态载荷）作用于煤岩体，容易引起煤岩体的突然失稳，诱发高强度岩爆灾害。地应力环境。因此，本文旨在研究煤体在动态载荷作用下的断裂特征及其声发射（AE）信号响应。结果表明，动态强度呈现“双峰”格局。出现两个波峰后迅速滴落，第二个波峰比第一个波峰高。随着子弹速度的增加（和施加的轴向静载荷条件），动态强度-应变曲线逐渐向上移动。两个峰之间的差异相对稳定。带裂纹和气孔的煤样在第一波峰处破坏明显，破坏区域主要集中在样板环附近。亚不稳定性阶段在总处理时间中的比例随着施加在样品上的冲击速度的增加而增加，范围从 3.17% 到 5.94%。轴向静载荷对整个过程时间中亚不稳定阶段的比例没有显示出显着的影响。AE峰值计数和能量随着冲击速度的增加而线性增加，而随着轴向静载荷的增加而减小。当采用相同的冲击速度时，两个峰值之间的差异随着轴向静载荷的增加而增加。由于煤体破裂时出现了第一个波峰，因此可以通过AE计数和能量来监测煤体的准确破裂时间。为探索动力荷载作用下煤岩体的断裂演化过程提供了一些启示，为远场波动荷载条件下岩爆演化机制的研究提供了参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。而它们随着轴向静载荷的增加而减小。当采用相同的冲击速度时，两个峰值之间的差异随着轴向静载荷的增加而增加。由于煤体破裂时出现了第一个波峰，因此可以通过AE计数和能量来监测煤体的准确破裂时间。为探索动力荷载作用下煤岩体的断裂演化过程提供了一些启示，为远场波动荷载条件下岩爆演化机制的研究提供了参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。而它们随着轴向静载荷的增加而减小。当采用相同的冲击速度时，两个峰值之间的差异随着轴向静载荷的增加而增加。由于煤体破裂时出现了第一个波峰，因此可以通过AE计数和能量来监测煤体的准确破裂时间。为探索动力荷载作用下煤岩体的断裂演化过程提供了一些启示，为远场波动荷载条件下岩爆演化机制的研究提供了参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。由于煤体破裂时出现了第一个波峰，因此可以通过AE计数和能量来监测煤体的准确破裂时间。为探索动力荷载作用下煤岩体的断裂演化过程提供了一些启示，为远场波动荷载条件下岩爆演化机制的研究提供了参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。由于煤体破裂时出现了第一个波峰，因此可以通过AE计数和能量来监测煤体的准确破裂时间。为探索动力荷载作用下煤岩体的断裂演化过程提供了一些启示，为远场波动荷载条件下岩爆演化机制的研究提供了参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。并为远场波动载荷条件下岩爆演化机制提供参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。并为远场波动载荷条件下岩爆演化机制提供参考依据。研究结果有助于进一步提高煤矿岩爆预测精度和控制。