简支钢桁梁桥面板及槽形梁架设结合施工技术  

Techniques to Install Simply-Supported Steel Truss Girder and Connect Concrete Deck Slabs and Trough Girder with Steel Trusses

作　　者：刘宏达[1] LIU Hong-da(The Fourth Engineering Co.,Ltd.,China Railway Major Bridge Engineering Group,Nanjing 210031,China)

机构地区：[1]中铁大桥局集团第四工程有限公司,江苏南京210031

出　　处：《世界桥梁》2022年第3期25-31,共7页World Bridges

摘　　要：平潭海峡公铁大桥深水高墩区非通航孔桥采用80(88)m跨径简支钢桁双层结合梁结构,上层高速公路采用混凝土桥面板,下层铁路采用槽形梁铺设有砟轨道。桥面板与槽形梁均采用工厂预制、现场安装的施工方式,即钢桁梁整孔架设完成后,先结合公路桥面,后结合铁路桥面。分别采用步履式桅杆架板机和可折叠支腿架槽机进行公路桥面板与铁路槽形梁架设,其中架槽机支腿折叠后可在有限空间内通过,便于设备的整体安装。施工时,首先分块架设公路桥面板并结合,然后架设铁路槽形梁,铁路槽形梁湿接缝分2次浇筑,先浇筑铁路横梁顶面无剪力钉区域湿接缝混凝土,达到设计强度后张拉铁路槽形梁通长预应力束,最后浇筑剩余剪力钉区域湿接缝混凝土。采用的施工技术可充分发挥公路桥面板受压性能,避免铁路槽形梁预应力施加到铁路横梁及钢桁梁上,防止预应力出现损失。The non-navigational channel bridge of Pingtan Straits Rail-cum-Road Bridge that is located in deep water area and has high-rise piers is a simply-supported steel truss girder structure with spans of 80(88)m。The bridge has two levels of decks,where the upper highway deck consists of concrete slabs and the lower railway deck is formed of trough girders topped with ballast tracks.The concrete slabs and trough girders were all prefabricated in the plant and delivered to construction site for erection.When the span-by-span erection of the steel trusses was finished,the concrete slabs were prepared to connect with the steel trusses,which was ahead of the placement of the railway deck.The concrete slabs were erected by derrick crane and the trough girders were installed by the launching gantry with foldable legs which could pass through places with low headroom,thereby facilitating the integral installation of facilities.During the construction,the installation and connection of the highway concrete slabs was performed before the railway trough girders,and the in-situ stitches in the railway trough girders were cast in two phases,with the stitches in the shear-stud-free zone on the top of the railway crossbeam cast first,once reaching the design strength,the full-length prestressing tendons in the railway trough girders were stressed,and the stitches in the remaining zones with shear studs were cast.By using these construction techniques,highway concrete slabs are well in compression,the railway crossbeam and steel trusses do not receive prestress from the railway trough girders,thus preventing the prestress loss.

关 键 词：简支钢桁梁 桥面板 槽形梁 湿接缝 架板机 架槽机 施工技术 

分 类 号：U448.211[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]