一、概述我国铁路桥,除极少数由于地形和地质情况而必须采用钢桁架梁或拱桥之外,其余均采用钢筋混凝土梁桥。每孔桥分为两片梁,梁的断面常采用形,只有低高度梁和跨度大干20m时才为Ⅰ字形。基本上采用桥梁预制厂预制,然后运到工地用架桥机吊 First, an overview of China’s railway bridge, with the exception of a very small number of steel truss girders or arch bridges due to the topography and geological conditions, the rest are used reinforced concrete girder bridge. Each hole bridge is divided into two beams, beams often adopt the shape of the cross-section, only the low height beam and the span of 20m when the shape was only Ⅰ. Basically prefabricated bridge prefabricated plant, and then transported to the site with erecting machine crane