The effect of increasing train speed on track transition performance

This paper shows the effect of increasing train speed on track transition performance. Earlier studies has been presented with high speeds and low speeds. The aim of these studies was to create a more gradual rail support transition on both sides of the structure. Most of the results presented show that the rail displacement and ballast stresses in the transition zone can be reduced by making several changes in the track superstructure elements and subgrade. In these studies all these modifications were studied for punctual high velocities but the effects between low and high speeds are still not analysed.
This research is presented as continuation of previous authors' work. The behaviour of track performance for higher train speeds in relation with vertical stresses and vertical displacements under sleepers (over ballast layer) is analysed numerically using the finite element program DARTS_NL.

The influence in sleeper separation from the slab track has been also analysed. The results show that the effect of increasing speed seems to be detrimental under sleeper's vertical displacements and stresses on ballast layer. When a train goes from slab to ballast increasing sleeper distance from the slab has a negative effect over the ballast stress.