当铁路或公路经过峭壁深谷时,如能因地制宜建造一座大跨度拱桥,定能令河山增色,巍然壮观。然而,旧式拱桥存在着某些缺点,例如:弧形拱圈产生很大弯矩,导致拱肋肥厚,多费工料;建造时需要大量钢拱架;现场灌筑工期较长等。这些缺点曾经影响拱桥的经济效益,阻碍拱桥的发展。经过各种探索和实践,近年来已较成功地建造了一种新型大跨度拱桥——上承式刚性梁柔性(推力)拱桥。它与旧式拱桥的主要区别是:结构受力情况产生了重大变化,拱肋仅承受轴向压力,故截面尺寸甚小,节省工料;采用悬臂拼装或悬臂灌筑法建造,因而不需钢拱架,并且能最有效地缩短工 When the railway or road through the cliff deep valleys, such as according to local conditions to build a large-span arch bridge, will be able to add color, towering spectacular. However, there are some shortcomings of the old arch bridge, for example: arc arch ring has a great moment, resulting in arch ribs hypertrophy, more labor charge; construction requires a large number of steel arch; These shortcomings have affected the economic benefits of the arch bridge, hindered the development of the arch bridge. After various explorations and practices, in recent years, a new type of long-span arch bridge, the rigid rigid beam flexible (thrust) arch bridge has been successfully built. The main difference between it and the old arch bridge is: major changes in the structure of the force situation, the arch ribs to withstand axial pressure, so the cross-sectional size is very small, save material; built using cantilever assembly or cantilever method, which does not require steel arch Rack, and can most effectively shorten the work