低透气性煤层群高瓦斯采煤工作面强化抽采卸压瓦斯机理及试验

针对低透气性高瓦斯煤层群首采卸压层瓦斯涌出量大、瓦斯治理困难的现实条件，在模型试验和理论研究的基础上，揭示出煤层群首采关键卸压层开采后采动影响区内顶、底板岩层裂隙的动态演化规律和卸压瓦斯运移规律，发现采空区侧存在“竖向裂隙发育区”，弯曲下沉带和底板膨胀变形带内煤体发生膨胀变形，煤层的透气性显著增加。2371(1)工作面煤气共采实践表明，工作面最大绝对瓦斯涌出量70.46 m3/min，平均56.71 m3/min，瓦斯抽采率达85.2%，其中抽采的高浓度瓦斯比例为67.25%，抽采的低浓度瓦斯比例为32.75%，保证工作面的安全回采，实现了煤与瓦斯安全高效开采。

Theory and experimental studies of enhanced gas drainage in the high-gas face of low permeability coal multi-seams

On the basis of model test and theory research for the problem of high gas emission when mining the key coal-seam in the multi-seams coal of the highly gas content and low permeability and the difficult actual condition of gas control,the permeability of the coal seam significantly increases because of the existence of the vertical crevasse growth area beside the mined direction,the curving submerged belt and the bulgy deformation band in the motherboard in coal,which is very benefit for gas drainage.The re...