不同基坑开挖卸荷方案对既有地铁隧道结构的影响研究  

Study on the influence mechanism of excavation unloading scheme on the structure of existing metro tunnel

作　　者：谢强[1] 马瑗婕 吴俊 董匡 程宝龙 涂正楠 XIE Qiang;MA Yuanjie;WU Jun;DONG Kuang;CHENG Baolong;TU Zhengnan(School of Civil Engineering,Chongqing University,Chongqing 400044,China;China Power Construction East China Survey,Design and Research Institute(Zhengzhou)Co.,Ltd.,Zhengzhou Henan 450003,China;Zhejiang Jiangnan Engineering Management Co.,Ltd.,Hangzhou Zhejiang 310013,China;Hehai College,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆大学土木工程学院,重庆400044 [2]中电建华东勘测设计研究院(郑州)有限公司,河南郑州450003 [3]浙江江南工程管理股份有限公司,浙江杭州310013 [4]重庆交通大学河海学院,重庆400074

出　　处：《现代城市轨道交通》2024年第5期77-82,共6页Modern Urban Transit

基　　金：浙江省建设科研项目(2021K121);中铁建设集团科研项目(4565QT2024001)。

摘　　要：随着城市建设不断推进,地下工程进入快速发展时期,基坑工程对下方既有结构的影响不可忽略。基于此,文章以某换乘地铁站项目上方基坑开挖为例,通过FLAC3D数值模拟软件,分析既有隧道结构上方基坑在一次性开挖、分区开挖、跳挖方案下隧道洞顶结构的变形状态。分析结果表明,无论是否考虑反压作用,3种方案下洞顶结构竖向最大变形排序均为:一次性开挖方案>分区开挖方案>跳挖方案,跳挖方案相较于一次性开挖方案和分区开挖方案隧道洞顶最大位移分别减少了48.6%、38.3%,可有效降低基坑开挖变形量。相关研究可为此类工程施工方案选择提供参考和借鉴。With the continuous advancement of urban construction,underground engineering has entered a period of rapid development,and the influence of foundation pit engineering on the existing structure below cannot be ignored.Based on this,this article takes the excavation of the foundation pit above a metro transfer station project as an example,and analyzes the deformation state of the tunnel roof structure above the existing tunnel structure under the conditions of one-time excavation,partition excavation,and skip excavation by using FLAC3D numerical simulation software.The analysis results show that the order of the maximum vertical deformation of the roof structure under the three working conditions is as follows:One-off excavation condition>zoned excavation condition>skip excavation condition.Compared with one-off excavation scheme and zoned excavation scheme,the skip excavation scheme could reduce the maximum displacement of the tunnel roof by 48.6%and 38.3%respectively,which could effectively reduce the excavation deformation of the foundation pit.The relevant research could provide a reference and example to build on for the construction project of this kind of engineering.

关 键 词：既有地铁 下穿隧道 开挖方案 数值分析 机理研究 

分 类 号：U231.3[交通运输工程—道路与铁道工程]