近距离岩巷掘进瓦斯超限原因分析及治理技术

Cause Analysis and Treatment Technology of Gas Overlimit in Close Range Rock Drivage

针对近距离岩巷掘进过程中瓦斯超限问题,以玉溪煤矿1302底板岩巷为研究对象,通过FLAC^(3D)数值模拟软件模拟得到巷道围岩的应力、位移分布情况。研究表明:巷道围岩变形严重是岩巷瓦斯超限的直接原因,风量过低是岩巷瓦斯超限的间接原因。提出了通风技术、千米钻机长钻孔提前预抽技术、"钻网"抽采截流瓦斯技术等瓦斯治理技术,应用结果表明:通过采用瓦斯综合治理技术后,岩巷瓦斯浓度(甲烷体积分数)由0.73%～0.96%降低至0.10%～0.50%,未出现瓦斯超标情况;岩巷掘进进度由原来的每月100 m提高到200 m以上,增幅达100%。可为同类地质条件的岩巷掘进瓦斯治理提供参考。

In view of the problem that gas overlimit in close range rock drivage process,taking 1302 floor rock roadway in Yuxi Coal Mine as the research object,the stress and displacement distribution of surrounding rock roadway was simulated by FLAC3D numerical simulation software.The results show that the serious deformation of surrounding rock is the direct cause of gas overlimit in rock roadway,and the low air volume is the indirect cause of gas overlimit in rock roadway.Some gas control technologies were put forward,including ventilation technology,pre-pumping technology for long drilling of 1000 m drilling rig and the technology that extraction gas using drilling network to cut off gas etc.,the application results show that after adopting gas comprehensive treatment technology,the gas concentration(methane volume fraction)in the roadway decreases,ranging from 0.10% to 0.50%,it is from 0.73% to 0.96% previously,there is no gas overlimit;the progress of rock drivage increases from100m per month to more than 200 m per month,with an increase of100%.It can provide reference for gas control under similar geological conditions.