Analysis of buckling in dual-gauge tracks Available to Purchase

Two types of track gauges are currently in use in the Spanish railway network: the traditional ‘iberian’ wide gauge of 1668 mm used in the conventional network and the international 1435 mm gauge used for the high-speed lines. The dual-gauge track, in which a third rail is added to the classical two-rail layout, has recently been proposed for the design of new lines. This solution implies a substantial modification of the classical ballasted track structure and thus requires an analysis of mechanical phenomena occurring on the rail-sleeper grid of the track. In particular, this study focused on lateral track buckling, produced by the axial compression stresses on the rails induced by increases in temperature. Whenever the axial compression force exceeds a critical threshold, the track could become unstable as significant lateral deflections may appear thus leading to unacceptable riding safety levels. In this case, the addition of the third rail increases the steel section and therefore the axial compression, which may lead to track instability. This study assessed this phenomenon in detail by means of a three-dimensional, nonlinear, numerical finite element model, based upon the latest reports of the European Railway Research Institute. Several conclusions have been derived from this study as regards the increasing risk of instability in a dual-gauge track.