The rockburst in steeply inclined coal seams (SICSs) is a typical dynamic instability event in coal-rock masses under dynamic and static loads. Existing physical experimental studies mainly investigate the quasi-static failure characteristics of coal-rock masses and lack physical experimental data gathered under applied dynamic loads, thus failing to reveal the full nature of the mechanism driving such a rockburst. On this basis, the spatio-temporal evolutionary characteristics of dynamic instability in SICSs were explored by conducting similar simulation experiments under dynamic and static loads. The results show that, under the compound influence of increasing dynamic loading intensity and decreasing distance from the dynamic loading source to the stope, the extent and severity of dynamic damage were aggravated correspondingly, and the characteristic parameters of displacements and accelerations varied non-linearly. The peak values and scope of influences of mining-induced stresses, degree of dynamic damage, and dynamic deformation of coal masses at the roof side were all greater than those at the floor side for the same sub-level; meanwhile, the rockburst also occurred inside the coal masses at the roof side, which reflected the asymmetry of the stress state and dynamic instability in SICSs. The vibration displacements at the roof side instantaneously reached a peak and the accelerations rapidly declined only after a single fluctuation during the rockburst, which revealed the explosive nature of such rockbursts. By contrast, the significant growth in the characteristic parameters of displacements and accelerations could reflect the remarkable destructiveness of rockbursts. This study may eventually lead to an experimental methodology for researching rockburst mechanisms in horizontal section mining of SICSs.

中文翻译：

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急倾斜煤层水平断面煤岩体动力失稳试验研究

急倾斜煤层（SICS）中的岩爆是动静载荷作用下煤岩体中典型的动态失稳事件。现有的物理实验研究主要研究煤岩体的准静态破坏特征，并且缺乏在施加的动态载荷下收集的物理实验数据，因此未能揭示驱动这种岩爆的机理的全部性质。在此基础上，通过在动，静载荷下进行相似的模拟实验，探索了SICS中动力失稳的时空演化特征。结果表明，在动态载荷强度增大，动载荷源至采场距离减小的复合影响下，动损伤的程度和严重性相应加剧。位移和加速度的特征参数呈非线性变化。在相同的水平下，顶板侧的开采诱发应力，动态破坏程度和煤团的动态变形的峰值和影响范围都大于顶板侧。同时，岩爆也发生在顶板煤体内部，反映了SICS中应力状态的不对称性和动力的不稳定性。顶板侧的振动位移瞬间达到峰值，而加速度仅在岩爆发生一次波动后迅速下降，这揭示了这种岩爆的爆炸性。相比之下，位移和加速度特征参数的显着增长可能反映了岩爆的显着破坏性。这项研究可能最终导致研究SICSs水平断面开采中岩爆机理的实验方法。