煤系地层软弱围岩隧道大变形施工控制技术

煤系地层属隧道施工中的不良地质,施工过程中除面临瓦斯燃烧或瓦斯爆炸、煤与瓦斯突出等高风险外,其围岩大变形问题也极为突出。通过地质调查和监控量测数据的综合分析,探讨地下水对煤系地层围岩的弱化效应,分析煤层隧道大变形出现的原因和发生机理。针对煤层隧道地质体工程特性和变形特点,提出相应的隧道大变形控制方法和技术措施,总结大变形侵限段换拱的施工方法,以有效控制围岩变形。

Control Techniques during Construction for Large Deformation of Weak Wall Rock of Tunnels in Coal Strata

The coal strata is classified as adverse geology in tunnel construction,during which except for high risks such as gas combustion or explosion and extrusion of coal and gas,etc.,large deformation of wall rock is also very prominent.Based on geological investigation and comprehensive analysis for monitored and measured data,this paper probes into weakening effect of underground water on wall rock in coal strata and analyzes causes and mechanisms of large deformation of tunnels in coal strata.In allusion of engineering characteristics and deformation features of geologic bodies of tunnels in coal strata,the paper proposes corresponding control methods and technical measures for large deformation of tunnels,and concludes construction methods for replacement of arches at invasion limit sections so as to control deformation of wall rock effectively.