隧道工程不良地质洞口段施工技术研究

Research on Construction Technology of Portal Section with Unfavorable Geology in Tunnel Engineering

外龙背隧道进口段为浅埋,埋深为3.0~23.38 m,且地质情况较为复杂,洞口段所处位置为崩坡积体,孤石分布密集且不明确,下部全风化岩层强度低,呈软塑状,超长双层管棚施工存在不确定因素,文章依托该工程,总结出了不良地质隧道洞口段施工技术,包括洞口加固施工技术和洞口段洞身施工技术,可为类似工程施工提供参考。

The portal section of Wailongbei tunnel is shallow buried,and the buried depth is 3.0-23.38 m.The geological conditions are complex,and the portal section is located in colluvial deposit with dense and unclear distribution of boulders.The lower fully-weathered rock layer has low strength and is soft and plastic.There are uncertain factors in the construction of extra-long double-layer pipe roof.Based on this engineering,this paper summarizes the construction technology of the tunnel portal section with unfavorable geology,including the portal section reinforcement construction technology and the tunnel body construction technology in the portal section,which can provide reference for similar engineering construction.