构造带石门揭煤诱导突出的力学特性模拟及声发射响应

Simulation experiment of mechanical characteristics and acoustic emission response during outburst induced by rock cross-cut coal uncovering in tectonic belt

为揭示地质构造区域石门揭煤诱导突出的机理,运用自行研发的大型三维煤与瓦斯突出模拟试验系统,对石门揭露断层构造带煤层的过程进行了相似模拟,同步采集分析了突出全过程的应力变化规律及揭煤过程的声发射响应规律,并对构造带揭煤突出过程的能量耦合跃迁失稳过程进行了理论分析。结果表明:在构造带掘进巷道的推进过程中,巷道上方的岩层和煤层均会经历应力增大和减小的过程,但构造区域煤层的应力集中系数大于岩层区域,呈现较强的应力敏感性;在开挖时和突出的过程中,声发射信号能较好地反映煤岩动态变化;在巷道掘进过程中,构造区域煤层不断积聚弹性能和瓦斯内能,并相互耦合逐步达到能量的极限平衡状态,一旦揭煤扰动到该系统,就会引起能量的耦合跃迁失稳,从而诱发突出。

Using the self-developed and three-dimensional simulation experimental system of coal and gas outburst, the process of rock cross-cut coal uncovering in fault structure zone was simulated, with the acoustic emission response and the stress evolution being collected. Also,the theoretical analysis was carried out on the energy coupling and transition unstability during the outburst of rock cross-cut coal uncovering in tectonic belt. The results show that the stress of rock and coal seam at the top of roadway experiences increase or decrease in the process of roadway advance in tectonic belt. With much more stress sensitivity in coal seam,the stress concentration factor of coal seam is higher than that of rock. During the process of uncovering and outburst, the acoustic emission response matches the coal and rock dynamic changes well. The elastic energy and gas internal energy of coal seam accumulate constantly during the roadway ad- vance in tectonic area, and then they couple gradually to achieve an ultimate energy equilibrium. Once the equilibrium system is disturbed by coal uncovering, the unstability of energy coupling and transition take place and induce coal and gas outburst. The research results are of theoretically significance for the mechanism research of coal and gas outburst in tectonic belt.