硬岩地层浅埋暗挖隧道成拱效应分析  

Analysis of Arching Effect of Shallow Buried Tunnel in Hard Rock Stratum

作　　者：龚旭东 GONG Xudong(Shanxi Railway and Underground Traffic Engineering Key Laboratory,Xi'an,Shaanxi 710043,China)

机构地区：[1]陕西省铁道及地下交通工程重点实验室

出　　处：《铁道工程学报》2019年第12期58-64,共7页Journal of Railway Engineering Society

摘　　要：研究目的:随城市化进程步伐的加速,浅埋暗挖法地铁隧道修建作为发展地下交通的重要手段。为研究浅埋暗挖隧道成拱效应,本文以青岛地铁工程的修建为研究对象,通过复变函数法弹性解析解及围岩应力和位移解析解计算围岩压力反推拱顶可承载厚度;通过拱盖变形量反推隧道拱盖承受的上覆荷载,进而说明在浅埋隧道也存在"成拱效应"。本文采用理论推导和数值模拟方法对浅埋暗挖隧道成拱效应进行模拟分析,并结合某车站现场实测数据进行说明。研究结论:(1)浅埋暗挖隧道围岩自身能承担上覆地层80%多的荷载,证明硬岩地层浅埋暗挖大跨车站也存在显著的自成拱效应,在设计与施工中需重点考虑;(2)硬岩浅埋隧道在一定覆岩厚度条件下存在成拱效应,围岩承受了大部分载荷,初支承受的荷载很少,印证浅埋大跨车站成拱效应存在;(3)本文研究结果可为今后硬岩地区浅埋暗挖隧道施工提供理论参考依据,并为类似隧道工程的施工与设计提供参考。Research purposes:Subway construction is an important means of developing underground transportation using shallow burying method,with the acceleration of urbanization.In order to study arching effect of shallow buried tunnel,this paper takes the construction of Qingdao Metro project as the research object.Vault carrying thickness can be pushed by calculating of the surrounding rock pressure through the elastic analytical solution of complex variable function method and the analytical solution of surrounding rock stress and displacement.The arching effect presents in buried tunnel,and the overburden load of tunnel arch can pushed by arch cover deformation.In this paper,the arching effect of shallow buried tunnels is simulated and analyzed by theoretical derivation and numerical simulation method,combined with the actual measured data of a station to explain.Research conclusions:(1)The surrounding rock of the shallow buried tunnel can bear more than 80%of the load on the overlying stratum.It is proved that there is a significant self-arching effect in the shallow-buried and deep excavation large-span stations in hard rock strata,which needs to be considered in design and construction.(2)The hard rock shallow tunnel has arching effect under certain overburden thickness conditions,and the surrounding rock is subjected to most of the load,and the initial bearing is subjected to very little load,which proves that the arch effect exists in the shallow-buried large-span stations.(3)The research results can provide theoretical reference for the construction of shallow buried tunnels in hard rock areas,and provide reference for the construction and design of similar tunnel projects.

关 键 词：浅埋 围岩压力 拱顶承载厚度 数值模拟分析 成拱效应 

分 类 号：U25[交通运输工程—道路与铁道工程]