Mine Safety Technology Branch,China Coal Research Institute State Key Lab of Coal Mining and Clean
Uilization,China Coal Research Institute Beijing Mine Safety Engineering Technology Research Center School of
Civil and Environment Engineering,University of Science and Technology Bejing

为解决高瓦斯薄煤层回采工作面邻近层及采空区瓦斯涌出难题,基于采空区上覆岩层移动破坏的规律,在朱家店煤矿4号煤层顶板布置高位钻孔的措施对卸压瓦斯进行抽采,并对高位钻孔开孔位置、终孔位置、终孔高度、开孔距离等抽采参数进行了研究。结合高位钻孔抽采效果分析,得出4号煤层顶板裂缝带高度在12 m左右、401工作面的初次来压步距为20~30 m、工作面"O"形圈的周边宽度为30 m左右、每组高位钻孔开孔间距为8~12 m较为适宜。现场应用结果表明:通过向采空区裂缝带内施工参数设计合理的高位钻孔,单孔抽采瓦斯纯量在0.01~0.24 m3/min,上隅角瓦斯体积分数由原来的0.89%降到0.31%左右,采煤工作面回风瓦斯体积分数由原来的0.65%降到0.20%左右,杜绝了采煤工作面回风及上隅角瓦斯超限。

In order to solve gas emission problem occurred in adjacent seams and goaf of coal mining face in gassy thin seam, based on moving failure law of overbur den strata in goaf,high level boreholes in roof of No.4 seam were applied to gas drainage to release gas pressure. A study was conducted on borehole initial drilling locatio n,borehole final location,borehole final height,distances between boreholes drilled and other gas drainage parameters. In combination with analysis on gas drainage effect of high level boreholes,crack zone height in roof of No.4 seam obtained was about 12 m,the first roof weighting distance of No.401 coal mining face was 20 ~ 30 m," O" ri ng edge width of coal mining face was about 30 m and space between opening boreholes of each high level borehole group would suitable be 8 ~ 12 m. The site applicatio n results showed that with high level boreholes with rational designed construction parameters in crack zone of goaf,drained gas pure volume of single borehole was 0. 01 ~ 0.24 m3/ min,gas concentration at top corner was reduced from previous 0. 89% to about 0. 31%,gas concentration of return airway in coal mining face was reduced fro m previous 0. 65% to about 0.20% and gas over limit occurred in return airway and top corner of coal mining face was eliminated.

国家科技重大专项资助项目(2011ZX05040-001-007)；