一、概况桥梁是公路的重要组成部分。我国在19世纪末开始有公路,因此也开始有了公路桥。初期的公路桥多为临时性或半永久性的小跨砖、石、木结构桥,永久性桥多为传统小跨石拱桥。较大河流或水深流急处,无法建桥,常设渡口维持交通。直到新中国成立时,公路钢桥还很少,大约只有60座。19世纪末到20世纪初,是建桥科技迅速发展时期。随着炼钢技术发展,钢桥被广泛采 First, an overview of the bridge is an important part of the road. My country began to have highways at the end of the 19th century and therefore also started to have road bridges. Most of the initial road bridges are temporary or semi-permanent small-span brick, stone and wood bridges, and permanent bridges are mostly traditional small-span stone arches. Larger rivers or water depths are in a hurry and can not build bridges, and permanent ferries maintain traffic. Until the founding of New China, there were only a few steel bridges on the road, about 60. Late 19th century to early 20th century, is the rapid development of bridge technology. With the development of steelmaking technology, steel bridges are widely adopted