ABSTRACT
This paper describes experimental research on a Dutch track to investigate the contribution of static and dynamic axle loads to both long-term degradation (settlement) and environmental vibration emission of a railway track on soft soil. To this aim, the rail has been instrumented to register the loading from passing trains, and the body of the track has been equipped with sensors to measure the dynamic structural response at different levels. A special focus has been placed on the dynamic axle load that is related to excitation frequencies lower than 200 Hz.
The research demonstrated that the eigenfield of the moving axle load, together with its local variation due to changing sleeper support stiffness or hanging sleepers, significantly affects trackbed degradation. Impacts from out-of-roundness of wheels proved negligible in the bandwidth below 20 Hz, but loaded track geometry in the short-wave regime proved a key factor for the emission of vibrations.
