三巷布置一侧回采煤柱空巷压垮机理及对策
Mechanism and countermeasures of abandoned roadway collapse in three-roadway stope mining one side pillar
-
摘要: 为探究大宁煤矿202工作面试行三巷布置一侧回采煤柱回采方式(简称跨采煤柱)期间发生空巷大面积切冒事故的原因,通过现场矿压观测与理论分析,建立了空巷上覆岩层力学模型,对空巷切顶机理进行了分析,并对制定的相应对策进行了实践。研究结果及现场实践表明:不合理的支护导致空巷上方基本顶发生超前破断,所形成“长关键块”的滑落失稳,是造成空巷切顶压垮的根本原因;当空巷采取充填措施且充填体强度达到1~1.2 MPa,即可有效地控制煤壁片帮和顶板下沉,并大幅改善空巷周围应力状态,形成有利于过空巷的局面,保证工作面的顺利推进。Abstract: In order to find out the reason of large area roof cutting and caving in abandoned roadway during the mode of mining one side pillar and three-roadway arrangement of 202 working face in Daning Coal Mine, based on the field observation and theoretical analysis of mine pressure, the mechanical model of the overlying strata in the abandoned roadway is established, and the mechanism and countermeasures of roof cutting and caving are analyzed and practiced. The research results and field practice show that unreasonable support causes the basic roof above the roadway to break in advance, and the sliding of the “long key block” is unstable, which is the root reason of the basic roof cutting and caving. When the back-filling measures are taken and back-filling strength of the abandoned roadway is 1 MPa to 1.2 MPa, it can control the coal wall and roof subsidence effectively and the stress state around the abandoned roadway can be greatly improved to form a situation that is conducive to passing through the abandoned roadway, ensuring the mining succeed.