School of Mining, Liaoning Technical University

为解决高瓦斯综采工作面瓦斯超限问题,针对赵庄煤矿1307工作面实际地质条件和开采技术水平,提出在工作面顶板布置走向高抽巷抽采瓦斯。为合理布置高抽巷,通过修正经验公式进行理论计算,利用FLAC3D模拟顶板覆岩运动,结合钻孔流量法现场观测得出垮落带最大高度为25.15 m,裂隙带最大高度为75 m,并确定高抽巷与煤层顶板垂距为30 m。通过对回风巷和高抽巷进行巷道应力分析,并考虑岩层垮落角的影响,选取高抽巷与回风巷水平错距为25 m。工程实践证明:高抽巷在抽采期间,抽采瓦斯纯量和浓度都保持在较高值,其大小波动受到工作面周期来压和地质条件影响;工作面回采期间,上隅角和回风巷瓦斯浓度都保持在较低值,避免了瓦斯超限问题。

In order to solve the gas overlimite problem of high gassy mechanized coal mining face, according to the actual geological condition and the mining tech nology level of No.1307 coal mining face in Zhaozhuang Mine, a high level gas drainage gateway layout along the roof strike of the coal mining face was provided. In 0 rder to make a rational layout of the high level gas drainage gateway, a correction of the experiential formula was applied to the theoretical calculation and the FLAC3D software was applied to simulate the roof strata movement. With the site observation of the borehole flow method, the highest height of the caving zone was 25.15 m, th e highest height of the cracking zone was 75 m and a vertical distance between the high level gas drainage gateway and the seam roof was 30 m. With a gateway stres s analysis conducted on the air return gateway and the high level gas drainage gateway and in consideration of the rock strata falling angle, a horizontal offset distance between the high level gas drainage gateway and the air return gateway selected was 25 m. The engineering practices showed that during the gas drainage period of th e high level gateway, the drained gas pure volume and concentration were kept in a high value and the fluctuation size was affected by the periodical strata pressure of the coal mining face and the geological condition. During the mining period of the coal mining face, the gas concentration in the top corner and the air return gateway w ere kept in a low value and thus the gas overlimite problem was avoided.