Evaluation Method of Track Vertical Irregularity on Bridges Based on Vehicle Running Status

Evaluating track irregularities is crucial for ensuring the safe operation of trains since they serve as the primary source of excitation for vehicle systems and track structures. In China's high-speed railway networks, bridges are frequently employed as alternatives to traditional track foundations. Operational experience has revealed that bridge segments frequently display track irregularities closely linked to their structural characteristics. Nonetheless, there is presently limited research on track irregularities, particularly on bridges. This paper systematically investigates the factors that influence the vibration response of the vehicle-track-bridge coupled system, with a specific focus on track irregularities on bridges. We study the influence of various critical parameters on the vibration response of the vehicle-track-bridge coupled system, utilizing finite element analysis software and multibody dynamics software analysis models and incorporating structural design data. Furthermore, we analyze the spectral characteristics of track irregularities on bridges, revealing the patterns of variation in dynamic vertical and lateral irregularities influenced by both bridge and track structures. Lastly, leveraging the correlation between track irregularities on bridges and the dynamic response of the coupled system, we introduce an assessment methodology and corresponding indicators for track irregularities on bridges. This methodology can establish a theoretical basis for the scientific assessment and maintenance management guidance of track irregularities on high-speed railway bridges.