Vibration serviceability assessment of a stress-ribbon footbridge

Abstract

With advancements in structural modelling and construction techniques, contemporary footbridges have become increasingly susceptible to vibrations induced by human activities, such as walking, jogging and jumping. This study aims to evaluate pedestrian-induced vibrations of a stress-ribbon footbridge. A three-dimensional finite element model of the footbridge was developed, considering nonlinear behavior of the structure and staged construction. Vibration serviceability assessment was carried out using HIVOSS design guidelines. Numerical modal analysis showed that the lateral modes of vibration cannot be excited in resonance by pedestrians walking. However, the footbridge is prone to vertical pedestrian-induced vibrations. The first torsional mode shape is the most critical. It can be excited in resonance by the first harmonic of the vertical pedestrian loading, yielding vibration response beyond the suggested acceleration limit in some extreme scenarios of pedestrian loading.