摘要
公路瓦斯隧道具有施工断面大、施工时间紧张、任务重等特点,特别是在隧道大断面揭露突出煤层时,将严重制约隧道施工工期。为解决公路瓦斯隧道大断面揭煤时所面临的钻孔施工数量大、预抽达标时间长和瓦斯抽采困难等问题,提出了隧道大断面揭煤时采用超高压水力钻割增透技术措施,并在华蓥山隧道大断面揭穿K4突出煤层期间进行了现场应用。施工定点抽采钻孔,对抽采钻孔煤层段进行超高压水力割缝,形成不同宽度的缝槽,增加煤层的暴露面积及扩大裂隙带。结果表明:经水力割缝措施后,煤层透气性大幅度增加,钻孔瓦斯抽采达标时间缩短了57.6%,钻孔抽采瓦斯浓度提高了约1.3倍,钻孔抽采瓦斯纯量提高了约1.4倍,成功实现了隧道大断面快速揭煤。
The highway gas tunnel has the characteristics of large construction sections,tight construction time and heavy tasks,especially when the large section of the tunnel uncovers the protruding coal seam,which will seriously restrict the construction period of the tunnel.In order to solve the problems such as a large number of drilling holes,long time for pre-drainage to reach the standard and difficulties in gas extraction met in the coal uncovering in the large section of the highway gas tunnel,the ultra-high pressure hydraulic slotting technology is proposed and applied in uncovering the K4 protruding coal seam in the large section of Huayingshan tunnel.Drilling holes were constructed at designated points,and ultra-high pressure hydraulic slotting was carried out on the coal seam with drilling holes,which forms different widths of slots,increases the exposed area of the coal seam and enlarge the fracture zone.The results show that the coal seam permeability is greatly increased,the standard time of gas-drainage by borehole to reach the standard is shortened 57.6%,the concentration of gas-drainage by borehole is increased by about 1.3 times,and the pure amount of gas-drainage by borehole is increased by about 1.4 times,successfully realizing the rapid coal uncovering in the large section of the tunnel.
作者
邓华易
DENG Huayi(CCTEG Chongqing Research Institute,Chongqing 400037,China;State Key Laboratory of the Gas Disaster Detecting,Preventing and Emergency Controlling,Chongqing 400037,China;College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China)
出处
《煤炭技术》
CAS
北大核心
2022年第9期118-120,共3页
Coal Technology
关键词
隧道大断面揭煤
水力割缝
煤层增透
快速
抽采达标
coal uncovering in large section of tunnel
hydraulic slotting
coal seam anti-reflection
rapid
drainage stantard
