首页|富水软土地区盾构近距离下穿地铁运营隧道的施工保护措施

富水软土地区盾构近距离下穿地铁运营隧道的施工保护措施

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[目的]富水软土地区盾构近距离下穿地铁运营隧道施工导致既有隧道结构变形控制困难,有必要对盾构下穿地铁运营隧道的施工保护措施进行研究.[方法]以南京地铁5号线盾构近距离下穿既有南京地铁1号线区间工程为例,运用MIDAS/GTS NX有限元软件对盾构近距离下穿施工进行了有限元模拟,提出了既有隧道主动保护措施,以及新建隧道盾构掘进控制措施.采用施工监测的方法,对盾构下穿期间既有隧道竖直方向位移和水平方向收敛进行监测.[结果及结论]具体施工保护措施包括:在盾构下穿施工前,对既有隧道受影响区段进行加固,通过微扰动注浆、永久性环向支撑和纵向拉紧条等措施有效降低了隧道变形,并使之符合变形控制标准;在盾构下穿施工中,基于既有隧道沉降量实时调整土压力和出土量,采取同步注浆、上下孔注浆量分配等方法进一步控制隧道变形.在盾构下穿施工完成后,针对地层的后期沉降问题,在盾构下穿段隧道内准备充足的补压浆材料和设备,根据沉降监测情况进行后续补压浆加固.上述措施能够有效减小盾构下穿施工对既有隧道的影响.
Protection Measures for Shield Tunneling Closely Under-passing Operating Metro Tun-nels in Water-rich Soft Soil Area
[Objective]In water-rich soft soil areas,it is dif-ficult to control the deformation of the existing operating metro tunnel structure caused by the construction of the shield tunne-ling closely under-passing.Therefore,it is necessary to con-duct research on corresponding protection measures.[Meth-od]Based on a project of Nanjing Metro Line 5 shield tunne-ling closely under-passing the existing section of Nanjing Metro Line 1,the MIDAS/GTS NX finite element software is used to simulate the construction of the shield tunneling.Then,active protection measures for the existing tunnel and control measures for the shield tunneling of the newly-built tunnel are put for-ward.The vertical displacement and horizontal convergence of the existing tunnel during the shield under-passing are moni-tored with construction monitoring methods.[Result & Con-clusion]The specific construction protection measures are as follows.Before the construction of shield tunneling under-pass-ing,the affected sections of the existing tunnel are reinforced with measures such as micro-disturbance grouting,permanent circumferential supports,and longitudinal tension strips to ef-fectively reduce the tunnel deformation and make it conform to the deformation control standards.During the construction,the earth pressure and the amount of excavated soil are adjusted in real time based on the settlement amount of the existing tunnel,and methods are adopted including synchronous grouting and the distribution of grouting amounts in the upper and lower holes to further control the tunnel deformation.After the com-pletion of construction,against the post-construction settlement problem of the stratum,sufficient grouting material and equip-ment for reinforcing grouting are prepared inside the tunnel sec-tion where the shield tunneling underpasses,and subsequent grouting reinforcement is carried out according to the monitored settlement.The above measures can effectively reduce the im-pact of the shield tunneling under-passing construction on the existing tunnel.

urban rail transitshield tunneling closely under-passing projectoperating metro tunnelwater-rich soft soil ar-eaconstruction protection measure

马西峰、金华、周游、陈少波、王羽、吴遥杰

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南京地铁建设有限责任公司,210017,南京

上海隧道工程有限公司,200232,上海

同济大学道路与交通工程教育部重点实验室,201804,上海

上海市轨道交通结构耐久性与系统安全重点实验室,201804,上海

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城市轨道交通 盾构近距离下穿工程 地铁运营隧道 富水软土地区 施工保护措施

2025

城市轨道交通研究
同济大学

城市轨道交通研究

北大核心
影响因子:0.689
ISSN:1007-869X
年,卷(期):2025.28(1)