高墩大跨连续刚构桥顶推合龙控制技术研究  

Study of Control Techniques for Closure of Long-Span Continuous Rigid-Frame Bridge with High-Rise Piers by Pushing

作　　者：魏建斌[1] 魏家乐 马玲[3] 

机构地区：[1]中交第二公路工程局有限公司,陕西西安710065 [2]陕西通宇公路研究所有限公司,陕西西安710018 [3]中交第一公路勘察设计研究院有限公司,陕西西安710175

出　　处：《世界桥梁》2014年第4期39-43,共5页World Bridges

摘　　要：高墩大跨连续刚构桥通常采用悬臂浇筑法施工,合龙控制难度较大,以国家高速公路包头至茂名线(G65)陕西境内铜川至黄陵公路某连续刚构桥为背景,对顶推合龙控制技术进行研究。结合顶推合龙的关键工序及要求,采用有限元软件建立该桥有限元模型,计算收缩徐变、高温合龙产生的墩顶顺桥向位移规律和墩身刚度、约束情况对顶推力的影响规律,得到收缩徐变和高温合龙会造成梁体缩短和墩顶顺桥向位移,合龙前进行顶推可有效解决该问题;顶推力受墩身刚度、约束情况的影响较大,也将产生较大的结构响应,应进行严格控制;依据分析结果及相关经验确定了合理的顶推力及合龙控制参数。控制结果表明:顶推合龙技术有效达到了补偿收缩徐变和高温合龙产生的顺桥向位移的目的,该桥最终合龙误差满足要求,控制精度较高。Long-span continuous rigid-frame bridges are usually constructed by cantilever cast-ing method , w hich brings great challenges to the control of closure . A continuous rigid-frame bridge on the Tongchuan to Huangling Highway in Shaanxi Province which belongs to part of the Baotou-Maoming National Highway （G65） was taken as the background to study the control tech-niques for the closure of the bridge of this type by pushing .Combined with the key construction procedure and demands of the closure carried out by pushing ,the finite element software was used to build the finite element model of the bridge ,so as to calculate the law of pier top displacement along the bridge length under the effect of concrete shrinkage and creep and high-temperature clo-sure as well as the influential law of the pier shaft stiffness and constraint condition on the pushing force .It is concluded that concrete shrinkage and creep and high-temperature closure can result in＆amp;nbsp;the girder shortening and pier top displacement along the bridge length ,and the pushing of the main girder carried out before the closure can effectively solve the problem .The pushing force should be strictly controlled because it is heavily dictated by pier shaft stiffness and constraint con-dition and is possible to lead to large structural response .According to the results of the analysis and the related experience ,the rational pushing force and closure control parameters are deter-mined .The results of the control indicate that the way of closure carried out by pushing effectively compensates the longitudinal displacement caused by concrete shrinkage and creep and high-tem-perature closure ,and the final closure error suits the requirements and the control precision is hig h .

关 键 词：连续刚构桥 悬臂浇筑 顶推合龙 收缩徐变 温度 纵向位移 顶推力 控制参数 施工控制 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U445.1[交通运输工程—道路与铁道工程]