平潭海峡公铁大桥墩旁托架施工关键技术  

Key Construction Techniques for Pier-Side Brackets of Pingtan Straits Rail-cum-Road Bridge

作　　者：陈娜 王东辉[2] 夏冬桃[1] 蔡小明 鄢禹 CHEN Na;WANG Dong-hui;XIA Dong-tao;CAI Xiao-ming;YAN Yu(Hubei University of Technology,Wuhan 430068,China;China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China)

机构地区：[1]湖北工业大学,湖北武汉430068 [2]中国中铁大桥局集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2020年第3期117-122,共6页Bridge Construction

摘　　要：平潭海峡公铁大桥3座通航孔桥均为钢桁混合梁斜拉桥,桥塔墩墩顶节段及辅助跨大节段钢梁均采用墩旁托架辅助安装。墩旁托架采用空间异型结构,由钢管支架和滑道梁结构组成。施工前采用MIDAS Civil有限元软件建立墩旁托架模型进行施工过程分析,结果表明墩旁托架结构满足施工要求。墩旁托架采用工厂预制组拼、现场整体吊装的方案施工,现场一次快速安装到位。在墩旁托架施工过程中,单元件制作及组拼均在工厂内进行,保证了制作精度,减少了现场工作量;托架采用大型浮吊整体吊装,在空中通过浮吊多钩配合实现其竖向及水平转体,快速将其调整至安装姿态;墩旁托架悬臂部分平联提前安装,在底部承台预埋件上焊接下放导向限位装置,提高了安装精度。The Pingtan Straits Rail-cum-Road Bridge consists of three navigational channel bridges which are all steel truss hybrid-girder cable-stayed bridges.To facilitate the installation of the top sections of the pylon piers and the large sections of steel girder in auxiliary spans,pier-side brackets were added,which are irregular spatial structures comprising steel tubular scaffolds and beams with traveling rails.Before construction,MIDAS Civil finite element software was used to establish the pier-side brackets model for construction process analysis.The results show that the pier side bracket structure meets the construction requirements.The pier-side brackets were prefabricated and assembled in the factory,integrally hoisted and erected at the bridge site,and low-ered into place with one-off operation.During the construction process of the pier-side brackets,the members were fabricated and assembled in the factory to ensure the fabrication accuracy and reduce the in-situ work amount.Large floating cranes were deployed to hoist the brackets and rapidly adjust and lower the brackets to the design position,where multiple lifting lugs were controlled to work in collaborated manner to realize the overhead vertical and horizontal rotation of the bra-ckets.Lateral bracings in cantilevers of the pier-side brackets were installed in advance and guiding limiters used for lowering the brackets were welded to the cast-in members in the base part of the pile cap,so as to improve the installation accuracy.Once the brackets were installed into position,the pier head and pier base were filled with concrete and prestressing tendons were tensioned,to further enhance the stability of the brackets.

关 键 词：公路铁路两用桥 斜拉桥 墩旁托架 异型结构 整体吊装 施工技术 

分 类 号：U448.212[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]