大跨度连续梁拱桥顶推施工力学行为分析

Mechanical Analysis of Long-Span Continuous Beam Arch Bridge under Incremental Launching Construction

摘要: 以新建郑州至万州铁路(河南段)跨南水北调中线干线方城段工程74 + 160 + 74 m连续梁拱桥拱肋异位拼装，梁顶顶推施工为研究背景，基于MIDAS CIVIL及MIDAS FEA分析软件，建立了拱肋顶推的整体有限元分析模型及拱肋横撑连接处的局部板单元模型，通过对落架过程的施工仿真确定了拱脚临时锁定的张拉力；分析了顶推过程中主梁的受力和变形，对顶推不同步和就位拱脚调整进行了模拟分析，确定了允许错偏量，保证了桥梁施工安全。

Abstract: Taking 74 + 160 + 74 m continuous beam arch bridge as research object, which located in the new Zhengzhou-Wanzhou Railway (Henan Section) crossing the South-to-North Water Transfer middle line, the integral finite element analysis model of the arch structure and local plate element model of the joints for arch-ribs and transverse braces were built up based on Midas civil and FEA to simulate ectopic assembling of arch ribs and pushing construction. Tension forces of arch foots to lock temporarily are calculated and stress and deformation of the main girder are analyzed during pushing construction. Finally, simulation analysis is made for the unsynchronized pushing and adjustment of the position arch foot, and the allowable offset is determined and the safety of bridge construction is ensured.