Lateral stability of CWR tracks in transition zones of open-deck steel bridges

Abstract

Relative displacements are introduced between steel bridges and continuously welded rail (CWR) tracks as the bridge girders expand and contract due to thermal effects. Depending on the fastening profile between the CWRs and steel bridge girders, additional forces are transmitted between the two, and when rail compression forces are introduced at the transition zones of the bridge, the risk of track buckling increases. The aim of this paper is to study CWR track buckling in the transition zones of open-deck steel bridges. In order to do so, a finite element model of a bridge is developed and calibrated based on the available literature. The model is then used to study the effects of a number of fastening profiles between the CWRs and steel bridge girders on track buckling in transition zone of the bridge. It is shown that girder temperature and location of lateral misalignment are the primary factors affecting the buckling temperature in the transition zone. Increasing the girder temperature by 45 °C can cause a drop of 11.5 °C in the track buckling temperature, a reduction of almost 19% compared to that of the open track. Furthermore, using zero toe load fasteners can reduce the risk of track buckling in the transition zone, yet there is little to resist the increasing gap size in case of a broken rail in winter.