地铁基坑开挖对紧邻桥桩及支护结构变形的影响  

Influences of Subway Foundation Pit Excavation on Deformation of Adjacent Bridge Piles and Retaining and Protection Structures

作　　者：于景志 刘燕[1,2] 宋享桦 杨帆 许泽 YU Jingzhi;LIU Yan;SONG Xianghua;YANG Fan;XU Ze(School of Civil Engineering and Architecture,University of Jinan,Jinan 250022,Shandong,China;The Engineering Technology Research Center for Urban Underground Engineering Support and Risk Monitoring of Shandong Province,University of Jinan,Jinan 250022,Shandong,China;Jinan Ding Hui Civil Engineering Technology Co.,Ltd.,Jinan 250002,Shandong,China;Water Resources Research Institute of Shandong Province,Jinan 250014,Shandong,China)

机构地区：[1]济南大学土木建筑学院,山东济南250022 [2]济南大学山东省城市地下工程支护及风险监控工程技术研究中心,山东济南250022 [3]济南鼎汇土木工程技术有限公司,山东济南250002 [4]山东省水利科学研究院,山东济南250014

出　　处：《济南大学学报（自然科学版）》2023年第6期734-738,745,共6页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金项目(51979122);山东省自然科学基金项目(ZR2022ME042)。

摘　　要：为了保证基坑开挖对紧邻既有桥梁桩基的安全性,结合某在建地铁车站实际工程,应用三维有限元软件MIDAS,对基坑开挖过程中桩体深层水平位移、地表沉降及桥墩竖向位移进行三维有限元模拟,并对现场实际监测结果进行分析。结果表明:基坑开挖造成支护结构产生鼓肚状变形,模拟结果曲线与监测结果曲线趋势一致;地表沉降呈漏斗状,模拟结果与监测结果具有较好的一致性;开挖基坑西侧桥桩JP23处桥墩的竖向位移大于开挖基坑东侧桥桩JP24处桥墩的竖向位移,说明距离越小,基坑开挖对桥桩的影响越大;根据模拟不考虑全方位高压喷射注浆桩加固,得到地表沉降最大竖向位移增大54.5%,并且桥墩竖向位移超过预警值,说明全方位高压喷射注浆加固对控制开挖变形具有重要作用。To ensure safety of foundation pit excavation for adjacent existing bridge pile foundations,combining an actual project of a subway station under construction and by using three-dimensional finite element software MIDAS,threedimensional finite element simulation was conducted on deep horizontal displacement of pile body,surface settlement,and vertical displacement of bridge piers during foundation pit excavation process,and actual monitoring results of the site were analyzed.The results show that the foundation pit excavation causes bulging deformation of retaining and protection structures.The trend of simulation result curves is consistent with that of monitoring result curves.The surface settlement is funnel-shaped,and the simulation results are in good agreement with the monitoring results.The vertical displacement of bridge pier at bridge pile JP23 on the west side of the excavation foundation pit is greater than that of bridge pile JP24 on the east side of the excavation foundation pit,indicating that the smaller the distance is,the greater the impact of foundation pit excavation on the bridge pile is.According to the simulation without considering all-round high-pressure jet grouting pile reinforcement,the maximum vertical displacement of surface settlement increases by 54.5%and the vertical displacement of the bridge piers exceeds the warning value,indicating that all-round high-pressure jet grouting reinforcement plays an important role in controlling excavation deformation.

关 键 词：地铁车站 基坑开挖 桥桩 支护结构 结构变形 

分 类 号：TU455.43[建筑科学—岩土工程]