竖向增层基坑开挖对既有车站结构变形影响规律  

Influence Law of Vertical Layer-incremental Foundation Pit Excavation on Existing Station Structural Deformation

作　　者：张志伟 尤强 张嘉树 许明杨 王海涛 ZHANG Zhiwei;YOU Qiang;ZHANG Jiashu;XU Mingyang;WANG Haitao(China Railway No.14 Group Corporation Tunnel Engineering Co.,Ltd.,250002,Jinan,China;School of Civil Engineering,Dalian Jiaotong University,116028,Dalian,China)

机构地区：[1]中铁十四局集团隧道工程有限公司,济南250002 [2]大连交通大学土木工程学院,大连116028

出　　处：《城市轨道交通研究》2024年第7期169-174,180,共7页Urban Mass Transit

基　　金：辽宁省自然科学基金计划项目(2020-MS-271);辽宁省教育厅科学研究项目(JDL2020014);中铁十四局集团科技研究开发计划项目(2020QT03)。

摘　　要：[目的]近距离基坑开挖的施工扰动会导致既有运营车站产生较大的变形,进而影响列车正常运行,因此需要研究竖向增层情况下,基坑开挖对下方既有车站的结构变形影响规律。[方法]以北京地铁6号线苹果园站三层段基坑工程为例,采用Midas GTS NX有限元软件建立基坑模型,分析竖向增层深基坑开挖引起的既有车站结构变形规律,并将模拟结果与现场监测结果进行对比。[结果及结论]随着基坑开挖的进程,既有车站结构的竖向变形不断增加,顶板变形曲线呈正态分布形式。车站顶板中跨变形值>边跨变形值,车站顶端竖向变形值>底端竖向变形值。当所取车站截面距基坑大于9.7 m(即0.81倍基坑开挖深度)时,边跨、中跨顶板的差异变形消失。对比数值模拟数据与实际监测结果可知,数值模拟分析所得的既有车站变形规律与实际监测结果一致,且最大变形量均小于控制值10.0 mm。[Objective]Construction disturbances from nearby excavation of foundation pit can cause significant deformation of existing stations in operation,thereby affecting the normal operation of trains.Therefore,it is necessary to study the influence of foundation pit excavation in vertically incremental layers on existing stations located below.[Method]Taking the construction project of Beijing Subway Line 6 Pingguoyuan Station three-level-section foundation pit as example,the Midas GTS NX finite element software is used to build a foundation pit model.The deformation law of existing station structures caused by deep foundation pit excavation in vertically incremental layers is analyzed,and the simulation results are compared with field monitoring results.[Result&Conclusion]With the progress of foundation pit excavation,the vertical deformation of existing station structures continuously increases,and the deformation curve of the roof plate exhibits a normal distribution.The mid-span deformation of the station roof is greater than the edge-span deformation,and the vertical deformation at station top is greater than that at the bottom.When the distance between the selected station section and the foundation pit exceeds 9.7 m(approximately 0.81 times the excavation depth),the differential deformation between edge-span and mid-span roof plates disappears.A comparison between numerical simulation data and actual monitoring results reveals that the deformation law of existing stations obtained from numerical simulation analysis is consistent with actual monitoring results,and the maximum deformation is less than the control value of 10.0 mm.

关 键 词：地铁 基坑开挖 既有车站 

分 类 号：U231[交通运输工程—道路与铁道工程] TU753[建筑科学—建筑技术科学]