A 3-D numerical study on the long-term evolution of track geometry under varying train speeds

Abstract

Railway infrastructure is essential for transportation worldwide, and ensuring its safe and efficient operation is of utmost importance. The ballasted track system is still the most common railway infrastructure type, but the ballast layer can deform and degrade over time, leading to various types of track irregularities and defects. This paper addresses two topics simultaneously that are both known to potentially increase the track geometry degradation: the train speed and railway transitions. The study is performed with an innovative three-dimensional numerical implementation developed to calculate the track's settlement caused by the repeated passage of railway vehicles, and explicitly considering the dynamic interaction between the vehicle and the track, and the evolution of the track's deformation over time. The presented results not only clearly demonstrate that the train speed can significantly affect the track geometry evolution at railway transitions, amplifying its degradation, but also that the long-term response at the entrance segment is quite different than the response at the exit segment of the railway transition. The results of this study can help develop more efficient measures to mitigate the harmful effects associated with the amplification of the track's response, improving the railway infrastructure's safety and efficiency.