ABSTRACT
Transition zones in railway tracks are locations with considerable changes in the vertical stiffness of the rail support. In such locations, the variation of the vertical stiffness together with the differential settlement of the track (when the foundation settles unevenly) on both sides of the transition result in extra maintenance cost and loss of passenger comfort. To study the dynamic behaviour of the transition zones, an advanced monitoring method and a developed FE model have been presented. The monitoring method for transition zones applying DIC can measure the dynamic displacements of the rails at multiple points in the approaching zones. The FE model of transition zones is capable of modelling the realistic settlement curve of the rails and the hanging distance of the sleepers. Moreover, it allows a detailed analysis of stresses in ballast and effects of the vehicle dynamics. Using these two methods, the dynamic track behaviour in transition zones has been studied. In addition, the long term settlement of track in transition zones is predicted and some countermeasure designs of transition zones are analysed.
