区域瓦斯抽放技术在立井施工防突中的应用

Application of Regional Gas Drainage Technology to Outburst Prevention in Mine Shaft Construction

为确保煤矿立井井筒施工过程中安全揭穿通过突出危险性煤层,在平煤四矿立井工作面揭露突出煤层前,按区域《防治煤与瓦斯突出规定》的要求,对立井施工区域防突措施中的瓦斯抽放技术进行了分析、设计和实施,确定抽放负压不小于13 kPa,初始抽放期的瓦斯体积分数不小于10%,抽放时间以抽出的绝对瓦斯量降到8 m3/t以下或者抽出的瓦斯体积分数不低于30%为准,采取设计的抽放措施后,钻孔瓦斯涌出初速度q和钻屑瓦斯解吸指标Δh2都在低指标范围内,立井穿过煤层前后,没有再出现类似区域打钻时的顶钻、夹钻现象,回风流中也没有出现瓦斯超限,施工过程中地压情况稳定,说明高地应力状况也得到了相应的缓解。

In order to ensure the safe opening and passing of the outburst danger seam in the mine shaft construction process,before the mine shaft sinking face to open the seam in No.4 Mine of Pingdingshan Coal Mining Group,according to the requirements of the regional Prevention Coal And Gas Outburst Regulations,the gas drainage technology in the regional outburst prevention measures of the mine shaft construction was designed and implemented.The drainage negative pressure was set not less than 13 kPa.At the initial drainage period,the gas volume fraction should not be less than 10%.The drainage time would be based on when the drained absolute value was reduced to less than 8 m^3/t or when the drained gas volume fraction was not less than 30%.With the designed drainage measures applied,both of the initial velocity q of the gas emission from the borehole and the gas desorption index Δh2 of the drilling cutting were in the low index scope.Thus,before and after the mine shaft passed the seam,there was no drilling against by the seam and no drilling jammed phenomenon occurred in the drilling operation in the similar region and there was no gas content over the limits in the return air flow.The strata pressure condition was stable during the construction process,which showed the high strata stress condition could be relatively released.