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

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 m in width.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 1.0 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.