我局管内京广、陇海干线上的桥梁,多数已使用了五十年以上,由于种种原因,产生了各种病害,需要进行整治改造。运营线上的桥梁施工不同于新线,既要保证正常运输,又要安全施工。以往对桥梁进行改建,或采用修建便线便桥、或在施工部位进行架空以维持行车。这些办法,有的造价高、工期长,有的要长期限制行车速度。无产阶级文化大革命以 I Bureau tube Jingguang, Longhai trunk bridge, the majority have been used for more than 50 years, due to various reasons, have a variety of diseases, the need for renovation. Bridge construction is different from the new line of operation, it is necessary to ensure normal transport, but also safe construction. In the past, the bridges were rebuilt, or the construction of the convenience bridge was used, or the construction site was overhead to maintain traffic. Some of these measures are costly, long construction periods, and others have long-term restrictions on the speed of vehicles. The Great Proletarian Cultural Revolution