An Assessment of Transition Zone Performance

Abstract

Transition zones between railway tracks on embankments or natural ground, and fixed substructures such as bridges and culverts, typically require extensive maintenance to retain acceptable track geometry. These high maintenance costs and the potential to cause delays to train services are of major concern for railway infrastructure managers. In view of the importance of the problem, surprisingly little research has been carried out to identify the fundamental causes of the poor performance of transition zones. To better understand the physical mechanisms involved, an extensive monitoring and investigation programme was undertaken on a typical transition zone in the Netherlands, comprising reinforced concrete approach slabs linking the normal track onto a concrete culvert. Accelerations and velocities of the track, soil, and approach slabs in response to passenger trains were measured, from which displacements were calculated. In addition, track settlements and pore water pressures were monitored over a 1-year period. This article presents and discusses the measurements made. The results highlight the problems associated with track quality at a transition zone, including the large dynamic displacements induced during train passage and the tendency for ongoing long-term movement. The implications of these for design and maintenance are discussed.

The behaviour of railway level crossings: Insights through field monitoring

“…Bowness et al, 2007;Priest et al, 2013;and Coelho et al, 2011). A short summary of the data they provide and their interpretation follows.…”

“…This could result in a group of sleepers that are never mechanically maintained becoming unsupported or hanging, reducing further the apparent support stiffness seen by the train and accelerating the rate of geometry deterioration. Even when a continuous minimum depth of ballast is provided, problems with hanging sleepers can arise if the feature being crossed is short and very stiff, as demonstrated by Coelho et al (2011) for a piled reinforced concrete culvert passing underneath a railway in the Netherlands.…”

“…Coelho et al, 2011, Tutumluer et al, 2012, and Paixao et al, 2013. A problem deserving just as much attention is that of transitions onto and off level crossings.…”

“…If successful, these transitions should involve the same or less maintenance cost as regular track, and there is much current research into their effectiveness (e.g. Paixao et al, 2013;Li and Davis, 2005;Coelho et al ,2011;Tutumluer et al, 2012). In contrast, there are no recognised transition designs for approaches to level crossings.…”

Performance assessment of peat rail subgrade before and after mass stabilization

“…DIC was first used to measure railway track displacements by Bowness et al (2006Bowness et al ( , 2007. Since then, DIC has been used in combination with geophones and (or) accelerometers to study ground deformations (Priest et al 2010) and transition zones (Coelho et al 2011;Le Pen et al 2014), as well as longitudinal rail displacements (Murray et al 2015).…”