Improved dynamic resilience of railway bridges using external dampers

Railway bridges may experience large vibrations from passing trains if the load frequency of the train coincides with the natural frequency of the bridge. For long and slender bridges on high-speed lines, this may occur within the range of the operational speed. In combination with low inherent damping of the bridge, excessive vibrations during train passage may pose both safety risks and riding comfort issues. One approach to mitigate the response of railway bridges and ensure resilience is to install external damping devices. In this chapter, a generalized theoretical model of a bridge-viscous damper system is derived based on the rotation of the bridge deck around the neutral axis. The dampers are installed horizontally in the vicinity of the roller bearing. A setup for a real-time hybrid simulation is described, in which a numerical model of a bridge is connected to a large-scale magnetorheological damper. From both cases, it is found that the vertical bridge deck acceleration could be significantly reduced, indicating that the proposed installation of the damping devices is applicable.