煤矿褶皱构造区冲击地压机理研究及防治实践

Study on mechanism of rock burst in fold structure area of coal mine and its prevention practice

针对胡家河煤矿402103工作面褶皱构造区开采期间煤岩应力异常和强矿震事件频发问题,基于数值模拟和现场实测方法分析了褶皱构造区工作面回采期间顶板、煤层和底板的应力演化特征,探讨了褶皱构造区冲击地压发生机理。模拟结果表明:工作面开采至褶皱构造不同区域时,褶皱构造区垂直、水平应力场分布具有明显的分区特性;褶皱构造区工作面开采时,水平应力起主控作用,开采至背斜轴部区域时顶板围岩稳定性降低,开采至向斜轴部区域时底板围岩稳定性降低,开采至翼部区域时煤层稳定性降低;基于煤矿褶皱构造区冲击地压发生机理,制定了402103工作面巷道围岩系统的顶板、煤层定向爆破释能降载防治方案,卸压后日均微震总能量下降47.6%,日均微震总频次上升16.7%,有效降低了工作面冲击危险性。研究结果对煤矿褶皱构造区工作面开采动力灾害防范具有一定借鉴意义。

Aiming at the problems of abnormal stress of coal and rock and frequent occurrence of strong mine tremors during mining in the fold structure area of No.402103 working face of Hujiahe mine,the stress evolution characteristics of roof,coal seam and floor during min⁃ing in the fold structure area were analyzed based on numerical simulation and field measurement,and the occurrence mechanism of rock burst in fold structure area was discussed.The simulation results show that when the working face is mined to different areas of the fold structure,the distribution of vertical and horizontal stress fields in the fold structure area has obvious zoning characteristics.When the working face is mined in the fold structure area,the horizontal stress plays a dominant role.When the working face is mined to the anti⁃cline axis area,the stability of the roof surrounding rock decreases.When the working face is mined to the syncline axis area,the stability of the floor surrounding rock decreases.The stability of the coal seam decreases when mining to the fold wing area.Based on the occurrence mechanism of rock burst in fold structure area,the prevention and control scheme of directional blasting energy release and load reduction for roof and coal seam of roadway surrounding rock system in No.402103 working face was formulated.After pressure relief,the daily aver⁃age total microseismic energy decreased by 47.6%,and the daily average microseismic frequency increased by 16.7%,which effectively reduced the risk of rock burst in working face.The research results have a certain reference significance for the prevention and control of mining dynamic disasters in coal mine fold structure area.