A STUDY ON COMFORT AND VIBRATION REDUCTION OF HUMAN INDUCED VIBRATION IN THREE-LIMB STAR-SHAPED PEDESTRIAN BRIDGES

With the innovation of engineering materials and economic development, modern pedestrian bridge design tends towards large spans and a more slender and elegant structure. This may lead to the bridge's natural frequency being close to the walking frequency of pedestrians, potentially causing resonance issues induced by human activities, which can affect the safety of the bridge structure and the comfort of the pedestrian experience. This paper takes a three-limb star-shaped super-flat beam-arch composite system pedestrian bridge as an example, establishes a three-dimensional detailed plate-shell model, and calculates the bridge's natural frequencies and vibration modes using the Lanczos method. It identifies the sensitive modes of human-induced vibration and evaluates their comfort, proposing a TMD (Tuned Mass Damper) design scheme for vibration reduction. By comparing the acceleration responses before and after vibration reduction, it is found that the TMD significantly reduces the bridge's vibrations, with the maximum human-induced vibration acceleration reduction rate reaching up to 97.9%. Additionally, the research indicates that the damping effect is influenced by the position of the TMD, and after the bridge is damped by the TMD, the comfort evaluation level of each vertical sensitive mode has reached the CL1 comfort level.