郓城煤矿冲击地压与载荷三带关系研究

Relationship between rock burst and the three zone structure loading model in Yuncheng coal mine

以郓城煤矿冲击地压事故为背景,研究了郓城煤矿1300工作面泄水巷冲击地压的致灾机理及防治方法。通过引入"载荷三带"覆岩结构模型,分析了郓城煤矿一采区上覆岩层空间结构及其运动规律,结合微震系统监测结果,验证了工作面回采期间载荷三带岩层的运动及加载特性。建立了"载荷三带"侧向支承压力估算模型,得到了1300工作面侧向支承压力分布规律,估算了工作面回采期间泄水巷煤岩体承受自重应力、构造应力和侧向支承应力的叠加总应力,该应力超过了该矿的临界冲击应力,判断郓城煤矿冲击地压是高地应力和构造应力作用下,厚层坚硬顶板长期运动发生应力积聚从而导致冲击。通过合理设计巷道平面位置避开侧向应力峰值区域、采用适当降低推采速度和合理设计煤层大直径卸压孔参数等措施,可以有效治理该类冲击地压。

With the typical case of rock burst accident in Yuncheng Coalmine as the background, the mechanism and prevention methods of the rock burst in drainage roadway of workface 1300 in Yuncheng Coal Mine were probed into. The three-zone structure loading model was introduced to ana- lyze the overlying rock structure and its movement during stoping in the first mining section of Yuncheng Coalmine. The microseismic monitoring results showed the three-zone movement and load- ing characteristics. An abutment pressure calculation model was built to reveal the distribution of the dip abutment pressure of workface 1300. The calculation results have shown that the superposition stress of self-weight stress, tectonic stress, and dip abutment pressure exceeded the strength of coal-rock mass during stoping. The crash of coal pillar under the self-weight stress, tectonic stress, and stress accumula- tion caused by the secular movement of thick and hard overburden led to the accident. To prevent this kind of rock burst, proper reduction of stoping speed, reasonable design of the position of roadways andsuitable setting of the parameters of pressure-relieving boreholes can be of great help.