Influence of loose sleeper on track dynamics and bending fatigue of rail welds

Abstract

For ballasted tracks, considerable maintenance work is needed to rail joints with fish plates and rail welds. In particular, it is very important to understand loose sleepers, which commonly appear when vertical track irregularities progress, when reviewing track deteriorations such as track settlement and fatigue of track materials. Track dynamic behaviours caused by loose sleepers can be predicted to some extent with a vehicle/track dynamic model constructed at RTRI, which was validated by early experiments at a track site. Estimating the bending fatigue life of rail welds supported by loose sleepers based on the analytical results carried out with the dynamic model, it was clearly understood that loose sleepers had great influence on the bending fatigue life of rail welds.