双线盾构隧道下穿桥梁桩基托换施作时机的影响研究  

Influence of Pile Foundations Underpinning Timing During the Construction of Double-Line Shield Tunnel Undercrossing Bridge

作　　者：宋锋 SONG Feng(China Railway 16th Bureau Group Co.,Ltd.,Beijng 100018,China)

机构地区：[1]中铁十六局集团有限公司,北京100018

出　　处：《国防交通工程与技术》2024年第4期80-84,40,共6页Traffic Engineering and Technology for National Defence

摘　　要：为了探讨既有桩基侵入盾构隧道开挖面时,桩基主动托换和双线隧道先后开挖的不同施工顺序对托换结构的影响,以成都市轨道交通17号线二期工程起点—阳公桥站区间盾构隧道下穿既有立交桥为工程背景,通过数值模拟的方法,分析不同施工顺序对托换梁沉降和倾斜,以及托换基桩位移和受力的影响。结果表明:当先进行桩基主动托换施工、再开挖托换结构外侧的隧道、最后开挖托换结构下方的隧道时,对托换结构的影响最小,两条隧道之间的托换基桩受力和水平位移小于另一侧的托换基桩,竖向位移则相反。研究有助于确定最佳的桩基托换和隧道开挖施工顺序。This study investigates the influence of active underpinning technology for pile foundations and the different construction sequences of double-line tunnel excavation on underpinning structures when existing pile foundations intrude into the excavation face of shield tunnels.The study uses the key section of the Chengdu Metro Line 17 Phase II project,specifically the shield tunnel section from the starting point to Yangongqiao Station that passes beneath an existing overpass,as an engineering case.The effects of different construction sequences on the settlement and inclination of the underpinning structure,as well as the displacement and force of underpinning piles,were analyzed through numerical simulation method.The results indicate that the construction sequence involving first implementing active underpinning construction of pile foundations,followed by excavating the tunnel outside the underpinning structure,and finally excavating the tunnel beneath the underpinning structure,has the least impact on the underpinning structure.Specifically,in this construction sequence,the underpinning piles located between the two tunnels experience less stress and horizontal displacement compared to those on the other side,while the vertical displacement shows the opposite trend.This study provides scientific guidance for determining the optimal sequence of pile foundation underpinning in actual engineering projects.

关 键 词：盾构隧道 双线隧道 下穿施工 桩基托换 施工顺序 沉降变形 侧向位移 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]