下承式铁路钢桁结合桥的桥式结构比较

Comparison of Bridge Structures of Railway Through Truss Composite Bridges

下承式钢桁结合桥刚度大,建筑高度低,行车噪声小,舒适度高,拟在我国客运专线、高速铁路建设和既有线路提速改造中应用。目前我国大陆还没有一座下承式钢桁结合桥。世界上已有一些成功应用的经验,但相关资料较少。本文介绍了日本北陆新干线、法国高速铁路地中海线以及我国台湾正在修建的高速铁路上几座有代表性的下承式钢桁结合桥和笔者等正在进行的下承式钢桁结合桥试验模型资料;将这些桥式结构按其与主桁和桥面系的结合方式分为三类;对桥式结构、受力特点、横向刚度、建筑高度等进行分析研究和比较;提出了下承式钢桁结合桥需要进一步深入研究的一些问题。这些工作将有助于下承式钢桁结合桥在我国的应用。

Through truss composite bridges have many advantages, such as high stiffness, low construction height, low noise and more comfort, and they are to be used in the construction of high-speed railways and dedicated passenger lines and in the speed-up reconstruction of existing lines in China. None of such bridge has been built in China mainland. There are some successful applications in the world, but little information available. Several typical through truss composite bridges in Japan, France and Taiwan and a model under testing by the author are introduced. These bridges are divided into three types according to the composite forms of the concrete slab with the steel structure of the floor system and the lower chord of the main truss. The structure feature, mechanical behavior, lateral stiffness and construction height of these bridges are studied. Problems needing further study are presented. The work are beneficial to the application of through truss composite bridges in China.