武汉汉江湾桥主桥设计关键技术

Key Design Techniques of Main Bridge of Hanjiangwan Bridge in Wuhan

武汉汉江湾桥主桥为(132+408+132)m中承式连续钢桁拱桥,桥面车行道按双向6车道布置,并预留拓宽至8车道条件。主桥拱肋采用变高度N形桁式两主桁钢桁架结构。主桁标准间距34 m,汉口岸边跨受限于总体线形,主桁间距由34 m变化至39.5 m。主桁中支点附近下弦杆根据受力要求采用Q690qE高性能桥梁钢。车行道桥面采用正交异性钢桥面板,车行道桥面下U形纵肋与钢桥面采用全熔透焊接设计。通过主桁节点弯折、钢桥面横坡变化等构造措施简化了主桁、联结系、桥面系的空间关系,降低了杆件制造难度,实现了桥面结构的曲线变宽。

The main bridge of Hanjiangwan Bridge in Wuhan is a half-through continuous steel truss arch bridge with a main span of 408 m and two side spans of 132 m.The deck carries six vehicle lanes(three on each direction)and is able to carry eight vehicle lanes to address the future traffic demands.The trussed arch consists of two lateral N-shaped trusses with variable depth.The two trusses are typically spaced 34 m at centers,due to the limit of the overall route alignment,the spacing of the two lateral trusses is enlarged from 34 m to 39.5 m in the Hanyang-bank side span.The lower chord below the main truss central point are made of Q690qE high-strength steel to accommodate the load bearing capacity requirements.The deck system is composed of orthotropic steel deck plates,where the U-ribs are welded with the steel deck plates in a full penetration manner.The main truss nodes are bent and the steel deck gradient is varying,to simplify the spatial relationship between the main trusses,lateral bracings and deck system,reduce the manufacturing complexity of the truss members and achieve the curved width variation of the deck.