基坑开挖引起下穿交叉隧道变形效应分析  

Analysis of Deformation Effect of Underpass Cross Tunnel Caused by Foundation Pit Excavation

作　　者：谢强[1,2] 马瑗婕 吴俊 薛孝强 涂正楠 Xie Qiang;Ma Yuanjie;Wu Jun;Xue Xiaoqiang;Tu Zhengnan(School of Civil Engineering,Chongqing University,Chongqing 400045,P.R.China;National Joint Engineering Research Center of Geohazards Prevention Areas(Chongqing),Chongqing 400045,P.R.China;Power Construction East China Survey and Design Institute(Zhengzhou)Co.,Ltd.,Zhengzhou,450003,P.R.China;Zhejiang Jiangnan Engineering Management Co.,Ltd.,Hangzhou,310013,P.R.China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]库区环境地质灾害防治国家地方联合工程研究中心(重庆),重庆400045 [3]中电建华东勘测设计研究院(郑州)有限公司,郑州450003 [4]浙江江南工程管理股份有限公司,杭州310013

出　　处：《地下空间与工程学报》2024年第5期1695-1705,共11页Chinese Journal of Underground Space and Engineering

基　　金：浙江省建设科研项目(2021K121);重庆市地质灾害防治中心科技项目(KJ2021050);重庆市规划和自然资源局科研项目(DK2021Z05null01C)。

摘　　要：以某地铁站换乘大厅工程为例,利用FLAC 3D数值模拟软件,分析总结了上跨深大基坑开挖对不同空间距离和分布形式的下穿立体交叉隧道的变形影响规律,并结合现场监测数据与数值模拟结果进行相互验证,结果表明:(1)基坑开挖卸荷对下穿隧道结构变形的影响主要表现为竖向位移,其变形量与基坑的空间位置和基坑岩土体开挖卸荷量密切相关;(2)1号线左、右线隧道全施工周期监测数据与数值模拟结果吻合较好,验证了数值计算方法对施工活动影响判断的准确性;(3)多种应力状态耦合的叠落隧道竖向位移受叠加效应影响显著,最大竖向位移位于影响因素较多的区域,最大竖向位移值为34.84 mm;(4)埋深较浅隧道对施工扰动比深埋隧道更加敏感,不同位置处的变形离散性更强,变形具有一定的整体性和协同性。Taking the transfer hall project of a subway station as an example,FLAC 3D numerical simulation software was used to analyze and summarize the influence law of the excavation of the deep excavation of the upper span on the deformation of the underpass three-dimensional cross tunnel with different spatial distances and distribution forms.Combined with the field monitoring data and the mutual verification of the numerical simulation results,the results showed that:(1)The effect of excavation unloading on the structural deformation of the tunnel is mainly manifested as vertical displacement,and its deformation is closely related to the spatial position of the foundation pit and the unloading amount of the rock-soil mass of the foundation pit;(2)The monitoring data of the whole construction cycle of the left and right tunnels of Line 1 are in good agreement with the numerical simulation results,which verifies the accuracy of the judgment of the influence of the numerical calculation method on construction activities;(3)The vertical displacement of the cascade tunnel coupled with multiple stress states is significantly affected by superposition effect,and the maximum vertical displacement is located in the area with many influencing factors,and the maximum vertical displacement is 34.84 mm;(4)Tunnels with shallow burial depth are more sensitive to construction disturbance than those with deep burial depth.The deformation dispersion at different locations is stronger,and the deformation has certain integrity and coordination.

关 键 词：基坑开挖 立体交叉隧道 数值模拟 接近施工 

分 类 号：TV551.4[水利工程—水利水电工程]