Experimental Analysis of the Vertical Track-Bridge Interaction in Railway Bridges with Ballasted Track

Realistic vibration predictions of railway bridges during high-speed train crossings require reliable dynamic input parameters for the applied calculation model.In particular, the dynamic stiffness and damping properties of the ballast superstructure for the mathematical consideration of the vertical track-bridge interaction significantly influence the generated calculation results.However, due to a striking scattering of model-related characteristic values available in literature, adequate and realistic consideration of the dynamic properties of the vertical track-bridge interaction in vibration predictions is associated with considerable uncertainties.This uncertainness illustrates the need to determine experimental-based and reliable characteristic values.For targeted and isolated research of dynamic characteristics of vertical track-bridge interaction, a unique large-scale test facility was developed at the Institute of Structural Engineering at TU Wien, which replicates a section of ballast superstructure on a railway bridge on a scale of 1:1 and excited to vertical movements.This contribution presents substantial results and findings from the experiments, focussing on the determination of the ballast superstructure's dynamic stiffness and damping values, which can further be implemented in practical applications for vibration calculations.In addition, the experiments are used to assess the currently applicable international and national standardised permissible structural accelerations for railway bridges during high-speed train crossings.