近距离下保护层开采冲击地压防治技术应用

Application of close lower protective seam mining in rock burst control

为探究近距离下保护层开采分别位于采空区、煤柱上方时的应力转移、能量释放规律,以唐山矿0250工作面为研究背景,利用微震监测、煤层钻孔卸压等监测手段,分析其在矿震事件分布及应力演化规律和影响范围,结果表明:下保护层特厚煤层开采后上覆煤层的微震事件频次、能量及分布均呈下降态势,且保护区影响范围内煤岩体的弹性势能得到释放,巷道的侧向支承压力向煤体深部转移,基于演化规律对工作面两巷冲击危险程度划分,针对不同危险等级采取不同强度卸压解危措施,研究结果对于指导下保护层工作面开采冲击地压监测防治工作具有重要的指导意义。

In order to explore the law of stress transfer and energy release when the lower protective seam is above the goaf and coal pillar of contiguous coal seams,taking Tangshan Mine 0250 working face as the research background,the distribution of mine microearthquake events,stress evolution law and influence range were analyzed by microseismic monitoring and coal seam pressure relief drilling.The results show that:after mining the lower protective seam of extra-thick coal seam,the frequency,energy and distribution of seismic event in the coal seam show a declining trend,and within the scope of protected areas,the elastic potential energy of coal and rock is released,lateral abutment pressure on the roadway transfers to deep part of coal mass.Based on the evolution law,the risk levels of rockburst is determined for the two lanes of working face,according to which different pressure relief measures are taken.The research results can guide the monitoring and prevention of rock burst in working face mining of lower protective seam.