隧道揭煤水力割缝卸压增透技术数值模拟研究及应用  

Numerical Study and Application of Pressure Relief and Permeability Enhancement Technology for Hydraulic Cutting of Tunnel Uncovering Coal

作　　者：熊文亮[1] Xiong Wenliang(China Railway Er yuan Engineering Group Co.,Ltd.,Chengdu 610031,P.R.China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《地下空间与工程学报》2020年第S01期291-296,共6页Chinese Journal of Underground Space and Engineering

摘　　要：隧道穿越突出煤层相较于煤矿井工开采,具有开挖断面大、施工作业人员密集、工期压力大等特点,发生煤与瓦斯突出、瓦斯燃烧甚至爆炸的危害程度也更高。本文采用理论分析结合数值模拟的方法对隧道穿越突出煤层过程中应力-渗流演化规律进行了研究,同时对比采用水力割缝措施和未采用防突措施情况下煤体抽采效果,并在四川攀大高速宝鼎2号隧道开展现场试验。数值模拟和现场试验结果表明,采用水力割缝技术措施后,割缝钻孔的单孔有效抽采距离是普通钻孔的4.75倍,割缝钻孔瓦斯抽采纯流量是普通钻孔的4倍;煤层的瓦斯含量W值和钻屑解吸指标K1值均降低至临界值以下,有效地起到防治煤与瓦斯突出的作用。Compared with coal mine mining,tunnel crossing outburst coal seam has the characteristics of large cross-section,dense workers and tense construction period.The hazards of coal and gas outburst,gas combustion and even explosion are also higher.In this paper,the evolution law of stress-seepage in the process of tunnel crossing outburst coal seam was studied by theoretical analysis and numerical simulation.At the same time,the effect of coal extraction under the condition of hydraulic slotting and no outburst prevention measures was compared.Field test was carried out in Baoding No.2 tunnel of Panda Expressway in Sichuan Province.The results of numerical simulation and field test show that the effective extraction distance of single borehole is 4.75 times of that of common borehole,and the pure flow rate of gas extraction in slotted borehole is 4 times of that of common borehole.The W value of gas content in coal seam and the K1 value of desorption index of drilling cuttings are both reduced below the critical value,thus effectively preventing and controlling the coal and gas outburst.

关 键 词：隧道揭煤 水力割缝 卸压增透 抽采纯量 FLAC3D 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]