长距离穿越顺煤层瓦斯隧道卸压消突方法研究

Research on Pressure Relief and Outburst Control Methods for Long-Distance Gas Tunnels Crossing Along Coal Seams

长距离穿煤隧道通常具有围岩破碎程度高、揭煤断面大、时间和空间紧张等特点,如何对此类隧道快速消突是隧道施工中面临的重大难点。以祁连山2#隧道为例,通过分析长距离穿越顺煤层瓦斯隧道的工程特点,对隧道瓦斯泄压增透抽采方法进行分析比选,最终选择水力割缝快速卸压消突方法,并建立了相应数值仿真模型,通过数值优化得到最优的钻孔布置间距和割缝布置间距。并通过现场试验,发现水力割缝快速卸压消突方法相对于传统钻孔抽采瓦斯法可以大量缩短抽采时间,验证了该方法的可行性及数值模拟结果的可靠性。本研究成果可为高瓦斯隧道水力割缝实际应用提供有效借鉴。

Long distance tunnels through coal seam usually have characteristics such as high degree of rock fragmentation,large coal mining section,and tight time and space.How to quickly eliminate outburst in such tunnels is a major challenge in tunnel construction.This article takes the Qilian Mountain No.2 Tunnel as an example to study the engineering characteristics of longdistance gas tunnels crossing coal seams,analyzes and compares the relevant gas pressure relief,permeability enhancement and extraction methods,and ultimately selects the hydraulic cutting seam rapid pressure relief and outburst suppression method.A corresponding numerical simulation model is established,and the optimal drlling and cutting seam layout spacing is obtained through numerical optimization.And through on-site experiments,it is found that the hydraulic slotting rapid pressure relief and outburst suppression method can significantly shorten the extraction time compared to the traditional drilling and gas extraction method,verifying the feasibility of this method and the reliability of numerical simulation results.The research results formed in this article can provide effective reference for the practical application of hydraulic slotting in high gas tunnels.