平潭海峡公铁两用大桥双层结合全焊钢桁梁设计  

Design of Composite Double Decks and Fully Welded Steel Truss Girder of Pingtan Straits Rail-cum-Road Bridge

作　　者：孙英杰[1] 徐伟[1] 

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056

出　　处：《桥梁建设》2016年第1期1-5,共5页Bridge Construction

摘　　要：平潭海峡公铁两用大桥深水区非通航孔引桥采用跨度88m和80m的双层结合全焊钢桁梁。其中88m钢桁梁采用带副桁的华伦式桁架,桁高13.5m,桁宽14m,标准节间长10.8m。上层公路桥面宽35.5m,采用钢筋混凝土板与钢桁上层纵、横梁结合,标准桥面板厚0.25m;下层铁路桥面采用双幅预应力混凝土槽形梁,竖墙和底板厚0.36m,利用剪力钉与钢桁铁路横梁结合。该桥采用双层结合桥面避免桥面铺装难题,利用公路纵梁缩短弱化桥面系的共同作用,通过抬高桁架节点位置实现曲线超高,优化铁路槽形梁结合顺序充分发挥预应力,选用钢梁全焊整体架设技术降低海上施工风险,实现了跨海大桥建设的标准化、工厂化、预制化、大型化。The composite double decks and fully welded steel truss girder having the span length of 88 m and 80 m is designed for the non-navigable span approach bridge of Pingtan Straits Rail-cum-Road Bridge over the deep water area. Of the two span length, the 88 m truss girder is the Warren truss with auxiliary trusses. The height of the truss is 13.5 m, the width is 14 m and the standard panel length is 10.8 m. The upper highway deck on the truss girder is 35.5 m wide and is a composite structure made up of the reinforce concrete deck slabs with standard thickness being 0.25 m and the stringers and cross beams of the truss girder at the upper deck. The lower railway deck on the truss girder is also a composite structure and is designed into the twin pres- tressed concrete channel girders that have the vertical wall and bottom slab thickness of 0.36 m and that are connected with the cross beams of the truss girder at the lower deck by the shear studs. The application of the composite double decks steel truss girder to the bridge can avoid the complex problem of deck pavement construction and the stringers of the highway deck can contrib- ute to the shortening and weakening of the joint action of the floor system. By raising the positions of the panel points of the truss girder, the curve superelevation of the girder can be achieved. The optimization of the connection sequences of the prestressed concrete channel girders and the cross beams can bring the prestress into full play and the choice of the full welding and integral erection techniques for the truss girder can reduce the risk of construction of the bridge over the sea and consequently can realize the construction of the bridge in a way of standardization, factory produc- tion, pre-manufacturing and large blocks.

关 键 词：跨海大桥 公路铁路两用桥 钢桁梁 双层结合 铁路槽形梁 全焊 结构设计 

分 类 号：U448.121[建筑科学—桥梁与隧道工程] U448.211[交通运输工程—道路与铁道工程]