高瓦斯综采面顶板覆岩卸压抽放瓦斯试验研究

针对我国高瓦斯低透气性煤层瓦斯预抽效果差的特点，在分析煤炭回采过程中顶板覆岩卸压移动规律基础上，提出了利用采动煤层顶板覆岩卸压裂隙发育特征，实施覆岩卸压区走向长钻孔抽放瓦斯。实践证明，顶板走向长钻孔覆岩卸压瓦斯抽放是解决低透气煤层瓦斯抽放率低的有效方法，回采面的瓦斯抽放率在20％以上；分析了顶板覆岩结构及关键层层位对覆岩移动规律的影响，给出了顶板走向长钻孔卸压抽放的合理布置区域。

Methane drainage experimental research for the stress-relief roof stratum of working face of high gas coal seam

A solution to the low gas drainage efficiency for lower-permeability gas-filled coal in China is suggested based on the theoretical analysis and model investigation of the stress-relief moving rules for the roof stratum during working. With this method, the gas is drained from the roof stratum with a strike long-distance drill according to the developing characteristics of the cracks resulting from the stress relief of the mining roof stratum. The contribution of the roof stratum structure and the horizon of the key seam to the displacing rules of the roof stratum is analyzed, and the proper zone for the strike long-distance drainage is provided. Judged from the practical experience, the strike long-distance drainage in the roof stratum, with a drainage percentage of 20% for working face, is an ideal method for the coal seam with lower permeability.