摘要
基坑开挖会使邻近隧道产生附加变形和内力,严重时甚至影响既有隧道的正常运行,因此其变形控制异常重要。基于深圳某快速化改造项目,利用PLAXIS 3D建立了三维有限元模型,分析了不同开挖层高及步长对下卧地铁线的影响。结果表明在实际施工中可以采用4m层高8m步长进行开挖施工,该方案与2m层高8m步长效果相差无几,但前者开挖至坑底整体范围较小,利于施工。采用8m步长较10m步长开挖范围小,对于下方隧道纵向的约束作用更大,更易于控制下方隧道变形,同时更利于在城市密集区域进行施工。
The excavation of foundation pit can affect the adjacent tunnel,inducing additional internal force and deformation,even influencing the normal operation of the existing tunnels.Hence,investigating the deformation control of metro tunnel is incredibly important.Based on a rapid renovation project at Shenzhen,a three-dimensional finite element model is established by PLAXIS 3D,and the influences of different excavation height and step length on underlying metro line are analyzed.The results indicate that 4 m excavation height and 8 m step length can be adopted in the actual construction.Its effect has little difference with the 2m excavation height 8m step length.Nevertheless,the former excavation scope is small,which is conductive to the construction.Adopting 8m step length has a smaller excavation range than 10m step length,which has a greater restraint on the longitudinal direction of the underlying tunnel,easier to control the deformation of the underlying tunnel,and more conductive to construction in dense urban areas.
作者
蔡昕宸
张建
宋旭
王诚杰
CAI Xinchen;ZHANG Jian;SONG Xu;WANG Chengjie(Urban Rail Transit Engineering Company Limited of China Railway 15th Bureau,Guangdong Shenzhen 518000,China;Shenzhen Metro Construction Group Company Limited,Guangdong Shenzhen 518000,China;College of Civil Engineering,Hunan University,Changsha 410000,China;Department of Civil Engineering,Zhejiang University,Hangzhou 310000,China)
出处
《低温建筑技术》
2020年第9期107-111,共5页
Low Temperature Architecture Technology
关键词
开挖方式
共线隧道
有限元分析
隧道变形
excavation methods
collinear tunnel
finite element analysis
tunnel deformation
