摘要
Abstract
The Channel continuous steel truss arch bridge in Dongping of Guangzhou, with the main span of (99 +242 + 99 )m, was known as “the first cross” in the Special Passenger Railway Line of Wuhan-Guangzhou.The bridge has the following characteristics: firstly, its arch with obvious spatial effect is composed of triple main trusses with a center distance of 14m.Secondly, it is a four-lane railway bridge with large traffic loads, and thus the associated fatigue design is a key issue.Thirdly, the cable-supported cantilever erection method with the cantilever length of 121 m is employed, and then it is necessary for ensuring the structural stability against overturning.Finally, due to the adoption of stress-free multi-point closure technique with complex system conversion in the bridge construction procedure, the construction process is more difficult.According to the construction characteristics of the steel truss arch bridge, in this study, some auxiliary constructing methods, such as ballast on side span, tower crane and stay cable are analyzed.Some closure technologies such as jacking up or descending truss on side support and longitudinal previous movement are also explored.Then, a reasonable construction method and a feasible closure technology are proposed, and the strength and stability stress of the members are checked for all considered cases to ensure the safety and reliability of the designed member during the construction phase.The computational results will be valuable for the future design and construction of steel truss arch bridges.关键词
钢桁拱/顶落梁/纵向预偏/合龙分类
交通工程
