土夹石沟谷富水区山岭隧道进洞技术  

The Tunnel Entrance Technology in Mountainous Water-Rich Areas in Soil Sandwich Stone Geology

作　　者：韩剑 方梁正 Han Jian;Fang Liangzheng

机构地区：[1]宁波市交通规划设计研究院有限公司

出　　处：《城市建筑》2023年第16期153-156,共4页Urbanism and Architecture

摘　　要：山岭隧道洞口一般存在浅埋、偏压、岩体破碎、稳定性差、易坍塌等问题,而进洞技术一直是山岭隧道设计与施工的难点。隧道沟谷地区土体含水丰富,土夹石地质更加大了进洞施工难度。削壁岭隧道洞口位于沟谷富水区,雨季山谷汇水急剧增加,且土体渗透性较强,水极易下渗,受水软化作用影响,地基承载力不足,隧道稳定性极差;除此之外,土体中含有多块滚石,属典型土夹石地质,隧道成拱效应差,管棚容易塌孔、偏位,隧道进洞存在极大困难。为顺利进洞,在施工中根据现场地形改进套拱形式,超前支护采用跟管管棚、小导管注浆止水及地基加固法,洞内开挖采用侧壁式导坑法,初期支护及二次衬砌均进行加强,通过以上措施最终顺利进洞,为类似工程提供了参考经验。There were so many problems,such as shallow burial,unsymmetrical pressure,rock fragmentation,poor stability and easy collapse in tunnel entrance.The Tunnel entrance technology has always been the difficulty in the design and constrcution of mountanous tunnel.For the tunnel in the valley area,the soil is rich in water,and the soil and rock mixing geoplogy further increases the tunnel entrance construction difficulty.Xuebiling tunnel entrance is located in the water-rich area of the valley.The valley water catchment increases sharply in the rainy season,and the soil permeability is relatively strong,it is very easy for the water to seep down.Affected by the softening effect of water,the foundation bearing capacity is insufficient,and the tunnel stability is very poor.In addition,the soil contains many rolled stones,is a typical soil sandwich stone geology,the tunnel arch effect is poor,the pipe shed is easy to collapse holes,devitate,and it is especially difficultu for the tunnel to go into the hole.In order to enter the cave smoothly,the construction improves the form of set arch according to the topography of the site.For the over-support,pipe shed,small conduit grouting to stop water and foundation reinforcement method are used.The cave excavation uses sidewall guide pit method.The initial support and secondary lining are strengthened.Through the above measures,finally the tunnel entrance construction goes smoothly,which provides a reference for similar projects.

关 键 词：土夹石 富水 隧道进洞 

分 类 号：U451[建筑科学—桥梁与隧道工程] U455[交通运输工程—道路与铁道工程]