Reassessing eurocode’s lateral vibration criteria for railway bridges

The normative criteria governing the running stability of trains on bridges, especially those limiting lateral vibration, were originally derived from ERRI/D214 research and adopted in EN 1990-Annex A. These standards prevent lateral resonance by requiring each span to have a lateral natural frequency above 1.2 Hz, evaluated under fixed-support conditions. While effective at the time, this limit was based on a narrow dataset of six simply supported bridges and does not capture the diversity of current designs. Resonance was mainly observed in the bridge itself, with limited evidence of its impact on train stability. Recent advances in computational modelling and an expanded dataset of bridge scenarios now allow for more sophisticated simulations of train-track-bridge interaction (TTBI), prompting renewed scrutiny of these guidelines. This study addresses these gaps by combining parametric analyses of 45 bridge scenarios with three train types (TGV, ICE 3, and LAAGRSS) under two track quality conditions. Using in-house TTBI simulation tools, the validity of the established 1.2 Hz lateral frequency threshold is examined. Results confirm resonance effects are confined to bridge displacements and do not propagate to vehicle dynamics, even under enforced frequency coincidence. Running safety indices (Nadal and Unloading) remained well below EN 14363 limits. Track quality emerged as the dominant factor influencing dynamic amplification, overshadowing the role of lateral frequency. These findings indicate that this threshold may be unnecessarily conservative for ensuring running stability and passenger comfort, suggesting the need for updated standards that better reflect contemporary railway bridge dynamics.