Influence of the train speed in the performance of a ballastless track in a transition zone

The ballastless track is the most popular railway system nowadays. This is due to the associated reduced maintenance costs and operations. Indeed, in recent years there has been a shift from the ballasted track to the ballastless track, mostly in Asia, but also in Europe. Considering both railway structures, their performance in transition zones is a major concern of the Railway Infrastructure Managers. These areas are characterized by an abrupt change in the track stiffness, which leads to the development of differential settlements and the growth of dips and bumps, accelerating the degradation of the track. Thus, it is crucial to have a methodology able to accurately predict the performance of the ballastless tracks in transition zones, mostly in the scope of high-speed lines. This work presents a detailed analysis regarding the evaluation of the performance of a ballastless track in an embankment-tunnel transition zone considering the influence of the train speed. In this analysis six different train speeds were adopted: 220 km/h, 360 km/h, 500 km/h, and 600 km/h. Moreover, the influence of the critical speed is also evaluated. The adopted and developed methodology is a novel and hybrid approach that allows including short-term and long-term performance, through the development of a powerful 3D model combined with the implementation of a calibrated empirical permanent deformation model.