超长多跨预应力连续梁桥支座预偏量设置分析  

Analysis on Predeflection Setting of Supports for Ultra-long Multi-span Prestressed Continuous Girder Bridge

作　　者：史彪之 怀光辉 查怀松 宋健 钱盛域 周小燚 SHI Biaozhi;HUAI Guanghui;ZHA Huaisong;SONG Jian;QIAN Shengyu;ZHOU Xiaoyi

机构地区：[1]中铁四局集团有限公司,安徽合肥230041 [2]无锡市城市重点建设项目管理中心,江苏无锡214000 [3]东南大学交通学院,江苏南京211189

出　　处：《城市道桥与防洪》2024年第12期82-86,M0009,共6页Urban Roads Bridges & Flood Control

摘　　要：跨数多于5跨且联长大于600 m的超长多跨预应力连续梁桥因其整体刚度大、行车舒适性好、车致振动小等优点在公路桥梁中应用逐渐增多,然而,在其施工过程中将经历多次合龙引起的体系转换,施工周期较长而需经历温度、徐变收缩等影响,因而使其支座纵向位移难以准确计算,为其设置合理预偏量成为了施工中的关键技术问题。为此,以某21跨超长多跨预应力连续梁桥的支座预偏量设置为研究实例,通过建立全桥有限元模型,在综合考虑温度、收缩徐变、预应力施加等影响因素后,分析了“从中间向两侧合龙”与“从两侧向中间合龙”2种合龙方案在支座预偏量设置上的差异,并基于变形-内力函数计算了支座滑动过程中摩阻力对支座位移的影响大小,实现了施工过程中主梁纵向位移的精确计算分析和有效控制。The ultra-long multi-span prestressed continuous girder bridge with more than 5 spans and a combined length of more than 600 m is increasingly used in highway bridges because of its advantages such as high overall stiffness,good driving comfort and low vehicle-induced vibration.However,in the construction process,it will experience the system conversion caused by multiple closures,and the construction period is long,which has to experience the influence of temperature,creep and contraction.As a result,it is difficult to accurately calculate the longitudinal displacement of the support.Setting a reasonable predeflection for it becomes a problem of key technologies during construction.Therefore,taking the predeflection setting of supports for a 21-span continuous ultra-long prestressed girder bridge as a research example,by comprehensively considering the influencing factors of temperature,shrinkage creep and prestress addition,a full-bridge finite element model is established to analyze the difference in the predeflection setting of supports with two closure schemes"from the middle to both sides"and"from both sides to the middle".Based on the force-displacement function,the influence of friction in the sliding process of the supports on the support displacement is calculated,which realizes the accurate computational analysis and effective control of longitudinal displacement of the girders during the construction.

关 键 词：超长多跨连续梁 支座预偏量 徐变收缩 温度作用 数值模拟 

分 类 号：U443.36[建筑科学—桥梁与隧道工程]