安庆长江铁路大桥主桥无索区钢桁梁架设技术

Erection Techniques for Steel Truss Girder of Main Bridge of Anqing Changjiang River Railway Bridge in Areas Without Stay Cables

安庆长江铁路大桥主桥为双塔三索面钢桁梁斜拉桥,钢桁梁采用N形平行桁式,3片主桁。主桥无索区钢桁梁共12个节间,总重6 041.5t,采用散拼法安装,其中6号至7号墩间8个节间钢桁梁在满布膺架上安装,6号至5号墩间4个节间钢桁梁采用悬臂安装。膺架墩对应每个钢桁梁节点布置,膺架共设置7排临时支墩,每排支墩由6根钢管桩组成,通过振动锤插打并接长钢管桩。利用200t浮吊反复站位上、下游的方法起吊拼装钢桁梁,完成无索区钢桁梁架设。该桥钢桁梁架设于2011年10月15日完成,经检测无索区钢桁梁的线形及应力均符合设计要求。

The main bridge of Anqing Changjiang River Railway Bridge is a steel truss girder cable-stayed bridge with double pylons and triple cable planes. The steel truss girder of the bridge is designed as the parallel truss type of N-shape and is composed of three main trusses. The girder of the main bridge in the areas without stay cables has 12 panels, totally weighing 6 041.5 t. The panels of the girder were installed by the piece-by-piece assembling method, of which the 8 panels between the Pier No.6 and Pier No.7 were installed on staging and the 4 panels between the Pier No.6 and Pier No.5 were installed by the cantilever method. The piers of the staging were arranged at the locations corresponding to each panel point of the girder and totally 7 arrays of the temporary piers were arranged. In each array of the piers, there were 6 steel pipe piles and the piles were driven in and extended by the vibrating hammer. The panels of the girder were lifted and installed and the erection of the girder was completed by the repeated utilization of the 200 t capacity floating crane alternatively placed at the downstream and upstream sides. The erection of the steel truss girder of the bridge was completed on October 15, 2011 and the inspection of the erection proved that the geometric shapes and stress of the girder in the areas without stay cables could accord with the design requirements.