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为了探索断层带瓦斯突出对巷道围岩的三维动力效应问题,基于峰值超压和速度方程等波动基本理论,结合大平煤矿10·20瓦斯突出事故,应用LS-DYNA与LS-Pre Post有限元软件,对冲击波传播特征以及巷道围岩的破坏规律进行数值模拟。研究结果表明:(1)沿巷道轴向,在扇形冲击波前锋与巷道顶板交界部位,岩体冲击质点的动力响应最为明显,速度峰值可达到78.015 cm/s,构成巷道围岩最大破坏区;最大破坏区前方为冲击波作用的盲区,岩体动力响应比较弱,本案例盲区长度约为2.1 m;最大破坏区后方为冲击波作用的衰减区。衰减区内围岩仍有侵蚀现象,本案例侵蚀区极限长达280 m。(2)在巷道横向剖面上,冲击波对巷道侧壁的侵蚀相对较轻。距离掌子面120 m范围内,顶板节点的速度和位移峰值均比侧壁节点的相应值高2~4倍;而120 m以外,顶板和侧壁的速度与位移值逐渐趋于相同。(3)当岩体较为软弱时,其冲击质点振幅较大。当岩体弹性模量减小到0.05 GPa时,振幅已增加到64.776 mm,巷道破坏效应也相应增大。而硬岩中的冲击波衰减较慢,容易诱发地(矿)震。
In order to explore the three-dimensional dynamic effect of fault zone gas outburst on roadway surrounding rock, based on the basic theory of wave overpressure and velocity equation, combined with 10 · 20 gas outburst accidents in Daping Coal Mine, LS-DYNA and LS-Pre Post finite element software , The characteristics of shock wave propagation as well as the destruction of roadway surrounding rock numerical simulation. The results show that: (1) The dynamic response of the impact mass of rock mass is most obvious along the roadway axial direction at the boundary between the fan-shaped shock wave front and the roadway roof. The peak velocity can reach 78.015 cm / s, which forms the largest destruction area of roadway surrounding rock. The blind area in front of the damage area is the shock wave, and the dynamic response of the rock mass is relatively weak. The length of the blind area in this case is about 2.1 m. The attenuation area behind the maximum damage area is the attenuation area of the shock wave. The surrounding rocks in the faulted area still have the erosion phenomenon, and the limit of the erosion area in this case is up to 280 m. (2) In the horizontal section of the roadway, the impact of the shock wave on the sidewall of the roadway is relatively light. Within 120 m from the face of the face, the peak velocity and displacement of the roof node are 2 ~ 4 times higher than the corresponding values of the sidewall node, while the velocity and displacement values of the roof and sidewall tend to be the same outside 120 m. (3) When the rock mass is relatively weak, the amplitude of impact mass is larger. When the elastic modulus of the rock mass decreases to 0.05 GPa, the amplitude of the rock mass increases to 64.776 mm and the damage effect of the roadway increases accordingly. The hard rock in the slow attenuation of shock waves, easily induced (mine) earthquake.