新建地下通道时下方地铁隧道保护方案研究  

Research on the Protection Measures of the Metro Tunnels under the New Underpass

作　　者：孙文昊 范东方[2] 胡威东[2] 王均勇[2] SUN Wenhao;FAN Dongfang;HU Weidong;WANG Junyong(National&Local Jonit Engineering Research Center of Underwater Tunnelling Technology,Wuhan,Hubei 430063,China;China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan,Hubei 430063,China)

机构地区：[1]水下隧道技术国家地方联合工程研究中心,武汉430063 [2]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道工程学报》2019年第12期86-91,共6页Journal of Railway Engineering Society

基　　金：国家重点研发计划《区域综合交通基础设施安全保障技术(2016YFC0802200)》

摘　　要：研究目的:为研究新建的地下通道卸载施工时下方既有地铁盾构隧道保护技术的可行性及其应用效果,结合某地下空间项目中地下通道方案研究阶段提出的两种保护措施,采用有限元数值模拟分析的方式对保护效果进行分析,并对推荐的实施方案与实际施工的监测数据进行对比。研究结论:(1)对下方既有隧道周边地层搅拌桩加固,然后再进行基坑抽条开挖的方法施工地下通道,理论上能够减小下方隧道的隆起变形,但是减小的程度不大;(2)对既有隧道周边进行地层加固施工,极易引起下方隧道水平收敛变形增大;(3)管幕+抗拔桩保护、地下通道采用预制箱涵顶进施工的方案,对隧道周边地层扰动小,可以减少隧道顶部卸荷量,并缩短施工周期,对控制下方隧道隆起和收敛变形效果显著;(4)推荐方案可应用于对周边建(构)筑物变形控制要求高的地下通道或隧道类工程的施工。Research purposes:In order to research the feasibility and application effects of the protecting measures of the metro shield tunnels during the construction of a new underpass,two different protecting measures of a typical project were taken as an example.Finite element numerical analysis results on the application effects were compared,as well as the monitoring data of the recommended measures.Research conclusions:(1)The measures which combined with reinforcing surrounding soil of the metro tunnels by cement mixing method and excavating foundation pit by core pulling method,is seem to reduce the uplifts of the metro shield tunnels in theory,but it’s not very effective.(2)Due to the broken of soil structures,the reinforcement can cause significant horizontal convergence actually.(3)Method of using pipe-roofs,anti-floating piles and jacking precast box-culvert,is more efficient at controlling tunnel deformation and shortening construction period.(4)The recommended scheme can be applied to the construction of underpass or tunnel projects with high requirements for deformation control of surrounding buildings(structures).

关 键 词：地下通道 盾构隧道 管幕 顶进预制箱涵 

分 类 号：U452.2[建筑科学—桥梁与隧道工程]