In-service vibration analysis of steel pedestrian bridges

Serviceability is a critical design criterion for modern footbridges, particularly lightweight and slender decks that are sensitive to pedestrian-induced vibrations. Excessive accelerations can compromise user comfort and, in extreme cases, trigger crowd-induced synchronization. While Eurocode 0 and Eurocode 1 provide guidance on pedestrian loads and acceleration limits, simplified models may be insufficient for modern, optimized designs. The EUR 23984 EN Technical Report addresses these challenges by integrating theory, experimental evidence, and practical verification procedures, emphasizing modal identification, damping estimation, comfort criteria, and step-by-step experimental testing. This paper presents an extensive experimental campaign conducted on a newly constructed 200 m pedestrian bridge over the Cesano River in Central Italy. The campaign included Ambient Vibration Tests to determine modal properties and Human-Induced Vibration Tests to measure response under controlled pedestrian loading. The results assessed serviceability according to recommended acceleration thresholds, confirming EUR 23984 EN as the main reference for pedestrian bridge design and testing in Europe.