宽煤柱沿空巷道顶板侧向预裂防冲技术

Roof Lateral Pre-cracking Prevention and Control of Rock Burst for Gob-side Wide Coal Pillar Roadway

部分冲击地压矿井由于受水、火、瓦斯等灾害影响,均留设了较宽的区段煤柱,并由此带来冲击地压威胁。采用顶板侧向预裂能够有效降低煤柱内集中应力,保护沿空巷道的安全。以崔木煤矿留设的35 m区段煤柱为研究对象,分析了采空区侧向顶板悬顶对煤柱应力分布的影响,并利用数值模拟和微震监测对不同顶板预裂位置的预裂效果进行了对比分析。研究表明:当预裂位置向采空区煤壁內错4~5 m时,沿空巷道围岩应力峰值最小,在该位置实施顶板预裂能够充分利用矿山压力,从而达到更好的预裂效果,该预裂方式在崔木矿22305工作面进行了试验,并在下区段22307工作面回采时进行了验证,顶板实施侧向预裂之后的冲击显现情况得到了显著降低。

Some rock burst mines are affected by disasters such as water,fire and gas.The wide coal pillar is set up in the mine,which increases the risk of rock burst.The roof lateral pre-cracking can effectively reduce the stress concentration inside the coal pillar and protect the safety along the goaf.In this paper,the 35 m wide coal pillar in Cuimu Coal Mine is taken as the research object.The influence of lateral roof overhanging on the stress distribution of coal pillar is analyzed.The effect of diflerent roof pre-splitting parameters is analyzed by numerical simulation and in-situ micro-seismic monitoring.The study shows that the peak area of the lateral stress in the goaf is the area with the maximum stress on the roof.The roof pre-splitting can be used to achieve better pre-splitting effect.The pre-cracking method was applied in 22305 and 22307 working faces of Cuimu Coal Mine,and the impact risk was significantly reduced.