Investigation on the Influence of Train Speed on Track Deflections in High Speed Railways

Construction of high speed railways is booming in the world. One of the main issues related to high speed railway is the non-uniform deflection of the rail along the track due to increases in train speed. This study focuses on investigations of the influences of strain speeds on track defections. For this propose, a model of railway track was developed. This model was then calibrated using field results available in the literature. The results of model calibration indicate that the consideration of the track support system nonlinearity has substantially effects on the theoretical results, concluding that the incorporation of the support system nonlinearity is a need in track modeling. From sensitivity analyses of the calibrated model, the effects of increases in train speeds on track deflections were investigated. It is shown that track deflections increase as the train speed increases up to the speed of 140 km/h. However, after this speed, the deflections of the track slightly reduce. It indicates that the critical speed of the track from the deflection point of view is 140 km/h. Research findings here indicate the necessity of further consideration of the critical speed in the design of high speed tracks.