一、前言 自全国解放至五十年代,全国铁路的轨道结构除少数试验段外,都是木枕短轨线路。虽然钢轨重量、钢轨长度、枕木辅设根数有了增加,但维修的修程和周期却可采用同一模式,即每年全起全捣或重起全捣,做一遍综合维修。 但六十年代初期以来,全国主要干线先后 I. Introduction Since the liberation to the 1950s, the orbit structure of the national railway has been replaced by a few test sections, all of which are short sleepers of wooden sleepers. Although the weight of the rail, the length of the rail and the number of sleepers have been increased, the same pattern can be used for the repair and the cycle of maintenance. That is to say, the system should be fully or completely restarted every year and be repaired comprehensively once again. However, since the early 1960s, the major national trunk routes successively followed