Determining the Degree of Residual Deformation Accumulation in the Ballast Prism of a Railway Track by Analysing the Intensity of Ballast Gravel Contamination with Coal Dust

To assess the rate of residual deformation accumulation in the ballast prism in relation to the degree of contamination by coal dust. Methods: The accumulation rate of residual deformations was quantified using the coefficient μ, derived from cyclic triaxial tests conducted within the GT 1.3.7 triaxial compression apparatus and subsequent regression analysis. Results: Laboratory tests and regression analysis have yielded values for the coefficient μ that indicated the intensity (rate) of residual deformation accumulation in the ballast prism. The investigations have been conducted on both clean stone ballast and ballast contaminated with coal dust at a moisture level of 6%. The findings demonstrate that as the percentage of coal dust contamination in the ballast increases, the rate of residual deformation accumulation intensifies by 1.5 times. With the values obtained for the coefficient μ, it was possible to calculate the ballast prism residual deformation. These calculations considered a tonnage of 400 million gross tons and were based on the premise that the bearing capacity of the formation is maintained, with track settlement occurring solely due to the deformations of the ballast prism. Practical significance: The results of the research allow for the forecasting of residual deformation accumulation in ballast stone as tonnage increases, particularly in relation to the level of contamination with coal dust. Consequently, this analysis enables the prediction of the ballast stone’s service life and the formulation of strategies for the technical maintenance of the railway track aimed at preventing deviations in the geometry of track grades III and IV.