地铁盾构不同角度侧穿既有铁路桥梁桩基变形分析  

Deformation Analysis of Bridge Pile Foundation of Metro Shield Tunnel Side Passing Existing Railway Bridge at Different Angles

作　　者：薛靖 穆坤 张建新[1,2] 杨磊 谭千万[3] XUE Jing;MU Kun;ZHANG Jianxin;YANG Lei;TAN Qianwan(School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;Key Laboratory of Soft Soil Engineering Character and Engineering Environment of Tianjin,Tianjin Chengjian University,Tianjin 300384,China;China Railway Erju Group Co.,Ltd.,Chengdu,Sichuan 610031,China)

机构地区：[1]天津城建大学土木工程学院,天津300384 [2]天津城建大学天津市软土特性与工程环境重点实验室,天津300384 [3]中铁二局集团有限公司,四川成都610031

出　　处：《河北工程大学学报（自然科学版）》2024年第5期56-63,共8页Journal of Hebei University of Engineering:Natural Science Edition

基　　金：天津市自然科学基金重点项目(18JCZDJC39200)。

摘　　要：地铁盾构隧道侧穿既有铁路桥梁时,对桥梁桩基会产生不同程度的影响,而不同的侧穿角度又会引起二者交叉范围内土体和桥桩产生不同的变形。基于天津地铁4号线北段某区间盾构隧道下穿某铁路桥工程,建立隧道-土体-桩基-桥梁整体三维数值分析模型,结合工程实测,针对隧道与铁路桥成85°、80°、76°、70°夹角的4种侧穿工况,分析不同夹角下隧道掘进对桥梁桩基的影响。结果表明,穿越角度的改变会对桥梁桩基变形和受力产生不同程度的影响,穿越角度越小,其对桥桩变形影响越大,存在最佳的穿越角度。当实际工程中无法选定最佳穿越角度(90°)时,在隧道与桥桩间设置隔离桩加固能有效减小地表沉降和桩基变形,进而对既有桥梁起到保护作用。When a subway shield tunnel passes through an existing railway bridge on the side,it will have varying degrees of impact on the bridge pile foundation,and different angles of passing will cause different deformations in the soil and bridge piles within the intersection range of the two.Based on the construction of a shield tunnel under a railway bridge in the northern section of Tianjin Metro Line 4,a three-dimensional numerical analysis model of the tunnel soil pile foundation bridge system was established.Combined with actual engineering measurements,the impact of tunnel excavation on the bridge pile foundation was analyzed for four lateral crossing conditions at angles of 85°,80°,76°,and 70°between the tunnel and the railway bridge.The results indicate that changes in the crossing angle will have varying degrees of impact on the deformation and stress of bridge pile foundations.The smaller the crossing angle,the greater its impact on the deformation of bridge piles,and there exists an optimal crossing angle.When the optimal crossing angle of 90°cannot be selected in practical engineering,setting isolation piles between the tunnel and bridge piles for reinforcement can effectively reduce surface settlement and pile foundation deformation,thereby protecting the existing bridge.

关 键 词：盾构掘进 穿越角度 数值模拟 桥梁桩基 隔离桩加固 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]