高地应力软岩隧道施工变形控制方法试验研究

Trial Research on Deformation Control during Tunneling in Soft Ground with High Geo-stress

为了研究高地应力软岩隧道施工变形控制方法,以兰渝铁路木寨岭隧道为例,通过对超前导洞法与三台阶法进行现场试验,分析了2种施工方法在高地应力软岩地层的变形控制效果,总结了三台阶法施工各阶段的围岩变形规律,主要结论为:1)超前导洞法与三台阶法施工,隧道中台阶是变形控制的重点;2)2种方法对高地应力软岩大变形总体控制效果相近,应结合其施工效率进行比选;3)隧道开挖后应及早施作仰拱,这对控制隧道变形极为有利。

The control of the deformation induced by tunneling in soft ground with high geo-stress is studied,with Muzhailing tunnel on Lanzhou-Chongqing railway as an example.Trails are made on pilot tunneling method and bench excavation method and the deformation controlling effects of these two methods are analyzed.The rules of the deformation occurring at different steps of bench excavation method are summarized.The conclusions drawn are as follows： 1） Regarding the pilot tunneling method and bench excavation method,the first bench is of great importance for the control of the tunnel deformation;2） The overall deformation control effects of these two methods are similar for tunnels in soft ground with high geo-stress,therefore proper excavation method should be selected from these two methods,on basis of the construction efficiency;3） The invert should be installed as soon as possible after the tunnel excavation,which is favorable to the deformation control.