Steel Rail is an important equipment of railway line. In the policy on major technical equipment of railway public works, in addition to clearly pointing out that the development direction of rail is heavy-duty, toughened and purified, there are also clear provisions on the rational use of rail. It is pointed out that the reasonable service cycle of reused rails should be determined according to the analysis of comprehensive economic benefits of rails, the system of phased use of rails should be implemented, and the renovation of old rails should be actively carried out.
1. The graded use of steel rail includes two meanings: the secondary or multiple use of rail and the reasonable replacement of rail in one use. The secondary use of rail refers to that after the rail is operated on the busy line, the old rail is repaired, and then it is laid on the railway with small traffic volume. It can prolong the service life of steel rail and improve the service efficiency of rail. The repeated use of heavy old rail can significantly strengthen the equipment of the whole non busy line. The use of heavy rail on the line with low freight density, even the old rail, will greatly improve the stability of the line and ensure the normal maintenance of the track with less materials and labor.
2. The old steel rail renovation is usually divided into three categories: comprehensive shaping rail, general shaping rail and welded long rail.
Foreign countries have always attached great importance to the hierarchical management and use of foresight. For example, the Federal Republic of Germany has been studying the relationship between rail and traffic volume and maintenance, in order to obtain the best economic benefits. The specific classification is: the new track laying is transferred to the primary track; When the height of Lou rail is reduced by 5%, it will be replaced and paved on the secondary rail; When the rail height is reduced by 8%, it is laid on the tertiary track. When Germany implements rail grading management, it takes re-use rail as a resource reserve. When a railway is to lay a new track, it should be considered in advance that a part of the re-use track should be laid. Because the heavier rail used is equivalent to the lighter new rail.
The high quality, durability and reliability of modern rail provide the possibility of reusing rail. The operation system of rail equipment shall be "team ladder type", and the rail shall be gradually moved to the section with small traffic volume with the weakening of its bearing capacity.
