超大跨度车站二衬拱盖法施工关键技术  

Key Construction Technology of Super Large Span Station with Secondary Lining Arch Cover Method

作　　者：刘洋[1] 向辉 张帅 蒋康 段胜泽 张卫中[2] 侯鹏伟 康钦容[2] LIU Yang;XIANG Hui;ZHANG Shuai;JIANG Kang;DUAN Shengze;ZHANG Weizhong;HOU Pengwei;KANG Qinrong(The Second Branch Co.,Ltd.of China Railway Tunnel Group Co.,Ltd.,Sanhe,Hebei065201,China;School of Resources&Safety Engineering,Wuhan Institute of Technology,Wuhan,Hubei430073,China)

机构地区：[1]中铁隧道集团二处有限公司,河北三河065201 [2]武汉工程大学资源与安全工程学院,湖北武汉430073

出　　处：《施工技术(中英文)》2025年第6期146-150,共5页Construction Technology

基　　金：国家自然科学基金(51804222)。

摘　　要：针对中风化含砾砂岩层建造车站存在围岩不稳定问题,以南京地铁7号线清凉山站浅埋暗挖超大跨度车站工程为例,通过数值模拟研究二衬拱盖法施工步序的围岩位移变化规律,得到影响围岩稳定性的关键步序,得出施工关键点,指导车站施工。研究表明:车站施工过程中拱顶和地表的围岩沉降值最大,分别为23.57,14.82mm;施工完成时拱脚处的围岩竖向位移大于其他部位,车站水平收敛呈现左侧向内收缩、右侧向外扩张,水平位移最大值为4.51mm;车站最大应力在两侧拱脚,拱顶应力大于隧洞下部,最大应力为0.52MPa。各步序中开挖拱部中上导洞的围岩位移变化较大,最大沉降为13.48mm;拱部二衬完成后围岩位移明显减小,隧道下部开挖最大围岩位移为4.56mm。二衬拱盖法的施工关键点是拱顶超前大管棚支护、拱脚和二次衬砌施工。拱部打设ϕ108×6大管棚,在棚管四周打8mm浆孔注浆加固;拱脚部位在拱架连接处设置长6m、入射角30°~40°的ϕ25锁脚锚杆,纵向托梁地基采用3根长4.5m、间距400mm的预应力锚杆支护;拱部二次衬砌采用900~3200mm厚C35钢筋混凝土。Aiming at the problem of surrounding rock instability in construction of subway stations in moderately weathered pebbly sandstone layers,taking the construction project of Qingliangshan Station of Nanjing Subway Line 7 as an example,the displacement variation law of surrounding rock in the construction step of secondary lining arch cover method is studied by numerical simulation.The key steps affecting the stability of surrounding rock are obtained,and the key construction points are obtained to guide construction of the station.The results show that:During construction of the station,the settlement values of the surrounding rock of the vault and the surface are the largest,which are 23.57mm and 14.82mm respectively.When the construction is completed,the vertical displacement of the surrounding rock at the arch foot is greater than that of other parts.The horizontal convergence of the station shows that the left side shrinks inward and the right side expands outward,and the maximum horizontal displacement is 4.51mm.The maximum stress of the station is at the arch feet on both sides.The stress of the vault is greater than that of the lower part of the tunnel,and the maximum stress is 0.52MPa.The displacement of the surrounding rock of the middle and upper guide holes in the excavation arch of each step sequence changes greatly,and the maximum settlement is 13.48mm;After completion of the secondary lining of the arch,the displacement of the surrounding rock is obviously weakened,and the maximum displacement of the surrounding rock in the lower part of the tunnel is 4.56mm.The key construction points of the secondary lining arch cover method are the support of the large pipe roof in advance of the vault,the construction of the arch foot and the secondary lining.A large pipe shed with a diameter ofϕ108×6 is set up at the arch,and 8mm grouting holes are drilled around the shed pipe to reinforce the pipe;ϕ25 locking anchor bolts with a length of 6m and an incident angle of 30°~40°are set at the arch foot at the co

关 键 词：地铁车站 超大跨度 二次衬砌 拱盖法 围岩 位移 施工技术 

分 类 号：U231.3[交通运输工程—道路与铁道工程]