Analysis of Residual Deformations Accumulation Intensity Factors of the Railway Track Located in the Polar Zone

Abstract

The article gives the analysis of the results of observations for evaluation of residual deformations accumulation intensity of a railway track structure operated in severe natural climatic conditions (the observation area is located beyond the polar circle). In addition, the following were taken into account: the structure of railway track (type of intermediate fastenings, rail base, the condition of ballast layer); railway line plan; passed-through tonnage; train travelling speed and axle load. The authors of the article received the following results: in the process of changing the stress–strain performance of a railway track as a function of passed-through tonnage, there was no stage in which the value of elastic subsidence of the superstructure elements would have a constant value; taking into account the operational and stress–strain characteristics of the studied section of the railway track, the maximum tensile stresses at the edge of rail base, caused by its bending and torsion due to the vertical and transverse horizontal impact of rolling stock wheels, will not exceed 40% of the allowable values in straight sections of the track; maximum compressive stresses in the ballast under sleeper in the under-rail zone will not exceed 85% of the allowable values in straight sections of track; compressive stresses at the top of subgrade in the under-rail zone will not exceed 85% of the allowable values in straight sections of the track; the values of the modulus of elasticity of the rail base on the experimental section of railway track are in the range from 6.0 to 59.0 MPa, which indicates an insufficient rigidity of the track and, as a result, leads to an increase of elastic subsidence of the rails, weakening of the track and contributes to increase in the intensity of residual deformation accumulations and the development of defects in the structure of railway track, which is confirmed by the data of the organization operating the railway track about identifying and removal of rails from the track as a result of their defectiveness.