Longitudinal track–bridge interaction due to sudden change of coupling interface

Stresses in continuously welded rails on bridges are strongly influenced by the coupling interface between track and bridge in longitudinal direction. Due to European codes this coupling is characterized by a nonlinear stiffness and by a significant dependence on whether the track is loaded by a train or not. The effect of the sequence ‘track unloaded–loaded–unloaded’ during the passing of a train onto the rail stresses is studied statically as well as dynamically with paying special attention to deformations from the load history; typically from seasonal temperature-change. This effect can increase the rail compression forces up to 10%.