非对称悬臂施工连续梁拱组合桥线形监控难点分析

对东淝河特大桥(112+224+112)m连续梁-柔性拱组合结构桥梁进行了有限元建模,分析了设计参数及施工工序对梁体累计位移的影响,将梁体结构的整体累计位移和合龙口两端的累计位移差作为线形监控难度的控制标准,对各种影响因素进行了综合分析和评价。研究发现:对于连续梁拱组合桥来说,结构自重和预应力效应为重要敏感性参数,对桥梁结构的累计位移影响较大;先浇筑部分非对称悬臂块段,后边跨合龙的施工工序为该类桥梁最优施工工序。

Analysis on Alignment Monitoring Difficulties of Continuous Beam-Arch Composite Bridge by Asymmetric Cantilever Construction

The finite element model of the Dongfeihe River Bridge-a(112+224+112)m continuous beam-flexible arch composite structural bridge is established.The influence of design parameters and construction procedures on the cumulative displacement of beams is analyzed.The overall cumulative displacement of beam structure and the cumulative displacement difference at both ends of the closure are taken as the control criteria for the alignment monitoring difficulty.The influencing factors are comprehensively analyzed and evaluated.The study result shows that structural dead weight and prestressing effect are the important sensitive parameters for continuous beam-arch composite bridges,which have a greater impact on the cumulative displacement of bridge structures.The construction procedure of firstly pouring the partial asymmetric cantilever block and closing the side spans later is the best one for this kind of bridge.