为防止被保护层卸压瓦斯大量涌向保护层工作面,进而造成Y型通风工作面回风巷和采空区瓦斯超限,依据保护层开采卸压理论以及采空区上覆岩层"裂隙三带"中的瓦斯运移规律,采用在Y型通风工作面布置高位钻孔抽采被保护层卸压瓦斯,并在羊东矿现场对高位钻孔关键参数进行了设计,终孔位置高度设计为24 m,倾向控制范围设计为9.5～60.0 m,终孔间距设计为10 m。现场应用结果表明:高位钻孔瓦斯抽采率为60.8%,回风巷平均瓦斯体积分数维持在0.27%,最高为0.46%,杜绝了Y型通风工作面回风巷和采空区瓦斯超限。

In order to prevent the pressure released gas of the protected seam flowed to the protective seam in a large quantity which would cause a gas content 0 ver the limit in the air returning gateway and goaf of Y type ventilation coal mining face, according to the pressure releasing theory of the protective seam mining and th e gas migration law of the crack three zone in the overburden strata above the goaf, high level boreholes set in the coal mining face with a Y type ventilation were appli ed to drain the pressure released gas from the protected seam.A design was conducted on the key parameters of the high level boreholes in the site of Yangdong Mine. The height designed of the final borehole location was 24 m, the inclination control scope designed was 9.5-60.0 m and the spacing designed of the finale boreholes wa s 10 m.The site application results showed that the gas drainage rate of the high level borehole was 60.8%, the average gas volume fraction in the air returning gatewa y kept at 0.27%，the max fraction was 0.46% and the gas content over the limit in the Y type air returning gateway and the goaf was eliminated.

国家自然科学基金资助项目(51074168)；