5.11 THE ISSUES OF RESTORING THE TEMPERATURE REGIME OF OPERATION AND INTEGRITY OF RAIL SPRINGS

Abstract

This article presents materials on the restoration of the operating temperature regime and the integrity of the rails of the contactless track. Options for performing work on the decomposition of temperature stresses are described.

Keywords: contactless track, rail web, work technology, fastening temperature, calculated interval.

Modern junctionless track designs, fixed to a constant operating mode within the calculated temperature range, do not require systematic temperature stress reduction.

The dissipation of temperature stresses in the rails of the continuous track is considered an exceptional work and is carried out in the following cases [2]:

- when reinforcing rail strips to the permanent operating mode, if they were previously laid outside the calculated interval;

- in necessary cases, before welding rail strips into longer ones;

- urgent need for repair work (for example, sudden appearance of a sharp angle in the plan) when the actual temperature of the rails exceeds the maximum temperature of the calculated interval;

- after the integrity of the rail web is finally restored, if it was welded at rail temperatures outside the calculated temperature range, etc.

There are two possible options for performing work to relieve temperature stresses (introducing the rail rails into the calculated fastening interval for a constant mode): unfastening the rails starting from one end, accompanied by the change of leveling rails (or one rail) from the same end of the rails; simultaneous unfastening of the rails from both ends, accompanied by the change of leveling rails from both ends of the rails.

When introducing the braids into the calculated fastening interval, the requirements for the uniform distribution of stresses along the length of each braid must be observed: the difference in the braid temperature during fastening during the entire production period should not exceed 3°C, and in the rail braid temperatures of both rail threads - not more than 5°C.

To reduce friction forces when moving rail members along the linings, either suspended rollers, or sliding pairs, or rolling supports installed on the linings, are used. After the sign, the whip is shaken with a percussion device. During the work process, the actual temperature of the rail joints along their length is measured, and the full change in the length of the joints along the ends, as well as the uniform distribution of stresses along the length of the joints, is monitored by the displacement of the marks applied to the rail sole above the beacon sleepers.