Physical interpretation of the railway track’s equivalent mass coefficients in track strength calculations

Objective: to determine the necessity to adjust the constant values of α0 and α1 coefficients, specified in the “Methodology for Assessing the Impact of Rolling Stock on the Track Under Conditions of Ensuring Its Reliability” (hereinafter referred to as the Methodology). Methods: an analysis of the analytical expressions employed in the Methodology and in the results of an experimental study of the oscillatory process in the subgrade soils, arising from track-rolling stock interaction, was conducted. Results: a functional dependence of the equivalent track mass (mtrack) on α0 coefficient and the equivalent wheel mass mwheel has been obtained. It has been established that the analytical expressions, utilized to determine α1 coefficient, lack physical significance, since they produce the same solution for any α1 value, confirming that mtrack is not influenced by the specific interaction mechanism between the track and the rolling stock. Practical significance: in view of the substantial changes in operational conditions affecting track-rolling stock interaction, since α0 and α1 coefficients were introduced in the 1972 Methodology for calculating the stress-strain state of the track, the research findings indicate the necessity to revise both the numerical values of these parameters and the methodologies employed to determine them.