大跨双层复合桁架桥施工阶段受力分析  

Analysis of Load Bearing Behavior of Long-Span Two-Deck Composite Truss Girder Bridge During Construction Process

作　　者：万鹏[1] 

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《世界桥梁》2016年第5期53-56,共4页World Bridges

基　　金：上海市科学技术委员会科技人才计划项目(08XD1422600)

摘　　要：为研究大跨双层复合桁架桥常用施工方法的优劣,利用已建桥梁参数,构建跨径布置为(80+104+80)m三跨连续双层复合桁架桥方案,在同等结构与配束条件下,利用MIDAS软件建立全桥有限元模型,对先架设整体钢桁架后浇筑混凝土、悬臂浇筑和采用辅助墩施工这3种不同施工方法的关键部位杆件成桥受力状态进行了对比分析。计算和实践结果表明,采用辅助墩为主桁施工提供临时支撑,可以减小复合截面钢桁骨架初始应力,提高预应力张拉效率,实现合理的成桥状态。To study the advantages and disadvantages of the construction methods commonly used to the long-span two-deck composite truss girder bridge,the scheme of a three-span continuous two-deck composite truss girder bridge with span arrangement of（80＋104＋80）m is proposed by using the parameters of the bridges already built.Under the condition of using the similar structural configuration and same amount of reinforcement,the MIDAS software was used to establish the finite element model of the overall bridge to carry out comparative analysis of the load bearing behaviors of the members at the key locations when the three different construction methods are used,including erecting the overall steel truss first and then casting the concrete,cantilever casting and using auxiliary piers.The results of the calculation and engineering practice prove that using the auxiliary piers to provide support for the main truss construction can reduce the initial stress of the steel truss skeleton with composite cross section,improve the efficiency of the tensioning of the prestressing tendons and realize the rational complete bridge state.

关 键 词：复合桁架桥 双层桥面 预应力张拉 悬臂拼装 辅助墩 桥梁施工 受力分析 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]