芜湖长江三桥2号桥塔下横梁支架设计与施工  

Design of Constructing Lower Crossbeam of Pylon No.2 of Third Wuhu Changjiang River Bridge Using Scaffold Method

作　　者：潘博[1,2] 刘爱林 王令侠[1,2] PAN Bo;LIU Ai-lin;WANG Ling-xia(China Railway Major Bridge Engineering Group Co. ,Ltd. ,Wuhan 430050,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China)

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430050 [2]桥梁结构健康与安全国家重点实验室,湖北武汉430034

出　　处：《世界桥梁》2021年第6期34-39,共6页World Bridges

基　　金：中铁大桥局集团有限公司科学技术研究与开发项目(2015-02-重大)。

摘　　要：芜湖长江三桥主桥为(99.3+238+588+224+85.3)m双塔双索面高低塔钢箱钢桁结合梁斜拉桥,2号桥塔下横梁采用落地支架法施工。下横梁支架由底模、承重梁、分配梁、牛腿和立柱等组成。立柱采用2排4列Φ1000 mm×12 mm钢管立柱,承重梁采用异形变截面工字梁以适应下横梁圆弧段线形,支承于立柱顶分配梁上。通过分层浇筑下横梁混凝土并张拉部分预应力有效减小了支架受力;计算支架变形并结合预压实测数据设置预拱度,有效控制下横梁线形;采用合理温控措施有效减小了因下横梁混凝土水化热产生的裂缝。The main bridge of the Third Wuhu Changjiang River Bridge is a cable-stayed bridge with five spans of 99.3,238,588,224 and 85.3 m.The bridge features its two pylons of different heights and the steel box and steel truss composite girder.The stay cables are arranged in double cable planes.The lower crossbeam of pylon No.2 was constructed by the scaffold method.The scaffolds were composed of base formwork,load-carrying beams,distribution beams,brackets and vertical posts.The vertical posts are steel tubular posts with diameter of 1000 mm and wall thickness of 12 mm,arranged in two longitudinal and four transverse rows.The load bearing beams was supported on the distribution beams on top of the vertical posts,which were I beams of adaptive cross-section to address the shape of circular arc section of the lower crossbeam.The concrete of lower crossbeam was cast in layers,in local part,prestressing tendons were added to reduce the loads on the scaffolds.The deformation of the scaffolds was calculated and the pre-loading data were monitored to set proper precamber,and in turn effectively control the geometry of the lower crossbeam.Proper temperature control measures were taken to effectively reduce the hydration heat-induced cracks in the lower crossbeam.

关 键 词：斜拉桥 桥塔下横梁 支架设计 落地支架法 分层浇筑 预应力张拉 线形控制 温度控制 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.3[交通运输工程—道路与铁道工程]