大埋深坚硬顶板厚煤层冲击地压微震监测及防治措施

针对深部矿井冲击地压形成机理复杂造成其监测预警困难的现状,本文介绍了一种适用于大埋深坚硬顶板厚煤层冲击地压的多因素耦合监测及防治方法。首先通过数值模拟分析临空面超前区域应力分布时空演化特征;其次,分析了冲击前兆发生时微震监测、声发射电磁辐射监测以及支架阻力监测曲线的变化规律,判断超前区域存在冲击危险性后,现场采取大直径钻孔进行卸压。以巴彦高勒煤矿311305工作面为工程背景开展了该方法的现场实践,通过数值模拟计算临空工作面回采至300m附近时超前应力大小和应力集中系数远超正常值,结合回采过程中工作面超前区域微震监测、声电辐射强度强度曲线的变化特征和现场超前区域30m内的钻检结果,判定311305工作面回采至300m附近时具有强冲击危险性,现场采用110mm大直径钻孔进行卸压,有效降低了311305临空回采面"初次见方"时冲击地压的发生几率。

Microseismic monitoring and prevention of working face rock roof burst in thick coal seam with hard roof and large buried depth

In view of the fact that the formation mechanism of rockburst in deep mine is complex, which makes it difficult to monitor and early warning. This paper introduces a multi-coupling monitoring and prevention method for rockburst in thick coal seam with hard roof. First, the temporal and spatial evolution characteristics of front abutment pressure was studied by numerical simulation. Second, the variation law of microseismic and acoustic emission electromagnetic radiation and support resistance monitoring curve when the rockburst precursor occurs is analyzed, large diameter boreholes are adopted to relieve pressure on working face. Taking the 311305 working face of Bayangaole coal mine as the engineering background, the field practice of this early warning and prevention method was carried out, the front abutment pressure and concentration coefficient is far exceed the normal value when the working face is mined to 300 m. Combined with the microseismic monitoring, acoustic emission electromagnetic radiation, and the drilling inspection results front 30 m in the working face analyses, there is strong rockburst risk when mining near to 300 m, and 110 mm large diameter borehole is used for pressure relief, which effectively reduces the occurrence of rockburst risk when 311305 working face mining to "the first square" area.