Thermal buckling behaviour of degraded railway tracks

At present, railway track buckling, caused by extreme heat, is a serious issue that causes a huge loss of assets in railway systems. The increase in rail tem-perature can induce a compression force in the continuous welded rail (CWR). It is important that a greater expansion in CWR can induce a higher risk of track buckling, especially when track defects exist. It is important to ensure the lateral stability of railway track in order to tackle the extreme heat. However, in fact, railway track can be progressively degraded over time resulting in poorer track stability. This may reduce the lateral resistance of railway tracks resulting in increasing the risk of track buckling. In this study, 3D finite element models are first developed to investigate the buckling be-haviour of ballasted railway tracks considering the large lateral track misa-lignment and component deteriorations. This study also proposes the spot replacement method at the certain spans to be fully restrained laterally in or-der to improve buckling strength. The new findings firstly highlight the buckling phenomena of degraded railway tracks. The results suggest the proper spans that need to be fully restrained in the lateral plane. This method provides a cost-effective solution to improve track buckling strength as the number of spans has been optimised in this analysis. The insight derived from this study will underpin the lifecycle design, maintenance, and con-struction strategies related to the spot replacement sleepers in degraded rail-way track systems.