软土基坑被动区加固对邻近地铁隧道的变形控制效果分析  

Analysis of Deformation Control of Passive Zone Reinforcement of Soft Soil Foundation Pit on Adjacent Subway Tunnels

作　　者：太俊 胡科 程宗亮 王磊 吴刚 周永强[2] TAI Jun;HU Ke;CHENG Zongliang;WANG Lei;WU Gang;ZHOU Yongqiang(Central and Southern China Municipal Engineering Design&Research Institute Co.,Ltd,Wuhan,Hubei 430015,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]中国市政工程中南设计研究总院有限公司,湖北武汉430015 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《水利与建筑工程学报》2023年第6期43-50,共8页Journal of Water Resources and Architectural Engineering

基　　金：中国市政工程中南设计研究总院有限公司科研项目(KY-N-J-2021-003)。

摘　　要：针对武汉市某全地埋式污水处理厂深基坑工程,采用三维有限元建立包含基坑支护结构、地下箱体结构、坑内工程桩以及邻近隧道的整体模型,模拟分析实际施工工况下基坑开挖对邻近隧道的影响,对比分析被动区加固空桩部分、实桩部分以及工程桩的作用对地铁隧道变形的控制效果。结果表明:被动区加固实桩、空桩及工程桩对地连墙的水平位移以及邻近隧道水平位移均有一定的控制效果,其中工程桩的影响最为显著;被动区加固空桩部分对地连墙及邻近隧道的竖向位移影响较小,而被动区加固实桩和工程桩虽抑制了坑底土体的隆起,却增大了地连墙及邻近隧道的竖向隆起。围护结构施工及基坑开挖引起隧道产生朝向基坑方向的水平位移及竖向隆起变形,主体结构施工对既有隧道的隆起具有明显的抑制作用,基坑施工全过程隧道变形量均能满足变形控制要求,表明基坑设计所采取的位移控制措施是切实有效的。As an effective deformation control method,passive zone reinforcement has been widely used in excavation construction of adjacent subway tunnels.Based on the deep foundation pit project of an all-buried sewage treatment plant in Wuhan City,three-dimensional finite element was used to establish an overall model including foundation pit supporting structure,underground box structure,engineering piles in the pit and adjacent tunnels,and the influence of foundation pit excavation on adjacent tunnels under actual construction conditions was analysed.The effects of empty pile part and solid pile part of passive zone reinforcement and engineering pile on subway tunnel deformation was compared.The results show that solid pile and empty pile of passive zone reinforcement and engineering pile have certain control effect on the horizontal displacement of the diaphragm wall and the horizontal displacement of the adjacent tunnel,and the engineering pile has the most significant influence.The empty pile of passive zone reinforcement has little influence on the vertical displacement of the diaphragm wall and the adjacent tunnel.The solid pile of passive zone reinforcement and engineering pile can greatly reduce the heave of the bottom soil,but increase the vertical heave of the diaphragm wall and the adjacent tunnel.The construction of exterior-protected system and the excavation of the foundation pit cause the horizontal displacement and vertical heave deformation of the tunnel towards the foundation pit,while the construction of the main structure has an obvious inhibition effect on the heave of the existing tunnel.The deformation of tunnel can meet the deformation control requirements during the whole foundation pit construction,which indicates that the displacement control method adopted in the design of foundation pit are practical and effective.

关 键 词：地铁隧道 被动区加固 工程桩 变形控制 软土基坑 

分 类 号：TU473[建筑科学—结构工程]