College of Safety Science and Engineering, Xi'an University of Science and Technology Key Laboratory of Western
Mine Exploitation and Hazard Prevention Ministry of Education, Xi'an University of Science and Technology

为了提高低透气性煤层采空区覆岩卸压瓦斯的抽采效果,采用微震监测技术,对工作面推进过程中采空区覆岩微震事件的演化过程进行了监测,进而分析了采空区覆岩的空间破裂特征,并依据微震监测分析得到的采动裂隙带位置及周期来压步距,设计了高位钻孔瓦斯抽采参数,检验了瓦斯抽采效果。结果表明:工作面回采期间周期来压步距在16 m左右,形成的采动裂隙带高度在50 m左右,据此设计的高位瓦斯抽采钻孔瓦斯抽采量和抽采体积分数分别提升了100%和150%,表明微震监测技术可准确探测采空区覆岩高位瓦斯富集区的空间位置,为瓦斯抽采钻孔设计提供了依据。

In order to improve the extraction effect of pressure relief gas in overlying strata of goaf under low-permeability coal seam, using micro-seismic monitorin g technology, the evolution process of micro-seismic events in overlying strata of goaf were monitored in the process of working face advancing, then the space rupture characteristics of overlying strata were analyzed, and on the basis of micro-seismic monitoring analysis of mining fissure zone position and periodic weighting length, th e parameters of high-level boreholes for gas extraction were designed, the effects of gas extraction were checked. The results show that periodic weighting length is ab out 16 m, height of mining fissure zone is about 50 m, the quantity and concentration of gas extraction increase by 100% and 150% respectively, the microseismic monit oring technology can accurately detecting the spatial position of gas enrichment region, which can provide reliable guidance and reference for design of gas extraction boreholes.

国家自然科学基金资助项目(51327007；51674189；51604213)；