浅埋偏帮(偏压)黄土隧道洞口处理技术

TREATMENT TECHNOLOGY OF SHALLOW BURIED BIAS LOESS TUNNEL ENTRANCE

由于黄土极易被雨水冲刷及黄土本身具有的湿陷性,黄土隧道洞口所处的地形、地貌大多较复杂,最常见的洞口处理技术有浅埋偏帮技术。徐家店隧道出口处于极端的浅埋偏压山体上,形成典型的浅埋偏帮状态,洞口施工方法和措施不当会引起洞口坍塌甚至滑坡,即使完成施工,由于日积月累的雨水冲刷也会给运营造成巨大安全隐患。徐家店隧道出口事先在偏帮浅薄侧施作混凝土挡墙及锚索拉结的加固措施,不仅保障了施工过程的安全,也保障了日后运营安全。基于此,对其方案和技术措施进行了总结,以供类似施工情况参考。

Due to the collapsibility of loess itself and its special sensitivity of water.Loess tunnel entrance mostly have complex stratum and physiognomy.Among these circumstances the most common one is shallow bias,the Xujiadian entrance of tunnel detail located on the mountain which has extremely shallow bias,following by a typical shallow state.Construction method of tunnel entrance and improper measures will lead to the hole collapse and landslide,even fortunately enough to complete the whole construction project,the increasingly accumulated pressure under precipitation could also cause a great potential safety hazard to operations.At the exit of Xujiadian Tunnel,concrete retaining wall and anchor cable tie were applied to the shallow side of tunnel in advance,which guaranteed the safety of the construction process and solved the security of future operation.In this research,the scheme and technical measures are summarized for reference in similar construction situations.