伺服钢支撑系统“双控法”在邻近地铁隧道深基坑中的变形控制效果分析  

Deformation Control Effect Analysis of Servo Steel Support System′Dual Control Method′in Adjacent Subway Tunnel Deep Foundation Pit

作　　者：高永伟 GAO Yongwei(China Railway Siyuan Survey and Design Group Co.,Ltd.,430063,Wuhan,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《城市轨道交通研究》2023年第11期132-137,共6页Urban Mass Transit

摘　　要：目的:为控制新建基坑变形,减小基坑开挖对邻近地铁隧道的影响,需探究轴力控制和位移控制双重控制方法(以下简称“双控法”)下伺服钢支撑系统对基坑及邻近地铁隧道的变形控制效果。方法:依托杭州某基坑工程建立了该基坑与邻近地铁线的数值模型,提出了“双控法”的伺服钢支撑系统轴力模拟方案和位移控制方案,设定了相应的计算步和监测工况。对6种伺服方案下的基坑沉降量及深层水平位移量进行了对比。对不同轴力控制值和单次位移变化量控制值下对基坑的变形影响进行了分析,进而得到本工程的伺服钢支撑系统体系的设置方案。基于此方案,对基坑土体深层水平位移、基坑地面沉降、邻近地铁右线隧道沉降的模拟值和实际监测值进行对比,以分析伺服钢支撑系统变形的控制效果。结果及结论:双层支撑伺服钢支撑系统比单层伺服钢支撑系统的变形控制效果更好。“双控法”控制指标中,轴力控制值的增加可使围护结构的最大水平位移量和地面沉降量明显减小,单次位移变化量控制值的改变对最终变形结果影响不大。“双控法”下的伺服钢支撑轴力系统能够有效控制基坑变形,保护邻近既有地铁隧道结构安全。Objective:In order to control the deformation of the newly built foundation pit and reduce the impact of excavation on adjacent subway tunnels,it is necessary to explore the deformation control effect of the servo steel support system on the foundation pit and adjacent subway tunnels under the dual control method of axial force control and displacement control(hereinafter referred to as the′dual control method′).Method:Based on a foundation pit project in Hangzhou,a numerical model of the foundation pit and adjacent subway lines is established.The servo steel support system axial force simulation scheme and displacement control scheme in′dual control′are proposed,corresponding calculation steps and monitoring conditions are set.The settlement and deep horizontal displacement of the foundation pit under six servo schemes are compared.The influence of different axial force control values and single displacement change control values on the deformation of the foundation pit is analyzed,and then the servo steel support system setting scheme for this project is obtained.Based on this plan,the simulated and actual monitoring values of deep horizontal displacement of foundation pit soil,ground settlement of foundation pit,and settlement of adjacent subway right line tunnels are compared,so as to analyze the control effect of servo steel support system deformation.Result&Conclusion:The deformation control effect of the double-layer support servo steel support system is better than that of the single-layer servo steel support system.In the control indicators of the′dual control method′,an increase in the axial force control value can significantly reduce the maximum horizontal displacement and ground settlement of the retaining structure.The change in the control value of a single displacement change has little effect on the final deformation result.Therefore,the servo steel support axial force system under the′dual control method′can effectively control the deformation of the foundation pit and protect th

关 键 词：邻近地铁隧道 深基坑施工 变形控制 伺服钢支撑系统 位移控制 轴力控制 

分 类 号：TU94+2[建筑科学—建筑技术科学] U231[交通运输工程—道路与铁道工程] TU433