In order to solve the problems such as heavy dust pollution and excessive gas flow during underground roadway excavation in coal mine,we used underground directional drilling technology to drill leading large-diameter two-ended borehole in the space of predriven roadway.By putting large-diameter PVC sieve tube into the borehole,with access to negative-pressure drainage pipelines,dust and gas were drained out through the negative pressure during the roadway excavation.Using waterjets and spraying measures jointly during the rock roadway excavation in Xianzhuang Mine in Huaibei,the maximum efficiency of dust suppression is up to 97.2％,which is 3.33 times that by the conventional measures of dust control.In addition,the total pure gas drainage volume during the roadway excavation in Luling Coal Mine is 221 000 m3.The applications show that leading large-diameter two-ended drilling is effective in reducing dust and draining gas,and thus is of great significance to coal mine safety production,improving working environment and increasing construction efficiency.%针对煤矿井下巷道掘进过程中粉尘污染大、瓦斯易超限等问题,研究采用煤矿井下定向钻进技术,在预掘巷道空间范围内施工大直径超前对穿钻孔,全程下入大口径PVC筛管,接入负压抽放管路,在巷道掘进过程中通过负压抽排粉尘及瓦斯.在淮北朱仙庄矿岩巷掘进过程中结合水射流、喷雾措施,降尘效率最大可达到97.2％,是传统降尘措施的3.33倍;在芦岭矿煤巷掘进过程累计抽采瓦斯纯量22.1万m3.应用结果表明,大直径超前定向对穿钻孔在降尘、除瓦斯等方面效果明显,对煤矿安全生产、改善作业环境、提高施工效率等方面具有重要意义.
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