The dynamic disturbance is one of the major reasons to trigger rock block sliding along the discontinuities of roof rock mass during the mining excavation. A self-developed test machine was used in this study to investigate the sliding instability of an isosceles trapezoid rock block triggered by dynamic disturbance. The sliding displacement, strain, and impact energy were monitored during the hammer impact under different lateral clamping load conditions. The experimental results show that the typical vertical displacement of key blocks can be divided into three modes post-disturbance depending on the clamping load and impact energy. Two distinct instability processes were observed once the key block began to lose stability and fall: Immediate falling and delayed falling. The difference between them involves the instantaneous slide distance and pendulum-type wave propagating on the sliding interface. The critical impact energy causing the key block to fall shows a nearly logarithmical increment with the gradually ascending lateral clamping load. Based on the energy analysis, an analytical solution to key block sliding displacement under dynamic disturbance is proposed, which accounts for the influence of clamping load, disturbance energy, interface friction coefficient, and key block incline angle. By comparison with the experimental results, the theoretical calculation is shown to effectively estimate the sliding distance of the key block under dynamic disturbance. This work may provide some sound guidance for the real-time assessment of key rock block stability via displacement monitoring.

动态扰动是在采矿开挖过程中触发岩石块沿顶板岩体的不连续性滑动的主要原因之一。这项研究中使用了自行开发的测试机来研究等腰梯形的滑动不稳定性动扰动触发的岩石块。在不同的侧向夹紧载荷条件下，在锤击过程中监测滑动位移，应变和冲击能。实验结果表明，根据夹紧载荷和冲击能量的不同，关键块的典型竖向位移可分为三种扰动后的模式。一旦关键块开始失去稳定性并坠落，就会观察到两个明显的不稳定过程：立即坠落和延迟坠落。它们之间的差异涉及瞬时滑动距离和摆式波传播在滑动界面上。导致钥匙块掉落的临界冲击能随着侧向夹紧载荷的逐渐增加而呈现出几乎对数的增长。在能量分析的基础上，提出了动力扰动下关键块滑动位移的解析解，它考虑了夹紧载荷，扰动能量，界面摩擦系数和关键块倾斜角的影响。通过与实验结果的比较，表明了理论计算可以有效地估计动态扰动下关键块的滑动距离。这项工作可能为通过位移监测实时评估关键岩块的稳定性提供一些合理的指导。