全焊连续桁梁-桁拱组合钢结构桥设计

Design of All-Welded Hybrid Steel Structure Bridge of Continuous Truss Girder and Truss Arch

上海市嘉定区桃浦路蕴藻浜大桥主桥采用66m＋136m下承式两跨连续桁梁一桁拱组合结构。承重体系为由箱形或H形杆件组成的2片桁架，主跨拱肋及边跨桁架均为变高度N形桁式。标准段拱肋全高4．6m，桁架高8．1～15m，宽1．1m。2片桁架之间设纵、横联及桥门架。桥面由纵、横梁体系及正交异性钢桥面板形成。杆件之间的连接均为焊接。吊杆采用高强度平行钢丝索。桥墩为两柱式，基础采用φ1．0m钻孔灌注桩群桩基础。经验算杆件强度和稳定性均满足规范要求，线性屈曲分析表明结构整体稳定性较好。

The main bridge of Yunzaobang River Bridge at Taopu Road, Jiading District, Shanghai City is a hybrid structure of two-span continuous through truss girder and truss arch with span arrangement 66 m＋136 m. The load-carrying system of the bridge is the two trusses made up of box-shape and H-shape members and the arch ribs at the main span and the trusses at the side span are all of N-shape trusses with variable height. An arch rib of the standard section is 4.6 m in total height , a truss at the side span is 8.1~15 m in height and 1.1 minwidth. In between the two trusses, the longitudinal and transverse bracings and portal frames are arranged. The floor system of the bridge is formed by the stringers, cross beams and orthotropic steel deck plates and all members of the trusses are connected by welding. The hangers for the arch are used with the high-strength parallel steel wire strands. The piers are the two-column ones resting on the foundations of φ1.0 m group bored piles. The checking calculation of the bridge proves that the strength and stability of the members can satisfy the relevant requirements in the codes and the linear bulking analysis demonstrates that the global stability of the structure is quite good.