Dynamic response of composite footbridges under running pedestrian load

In this paper, a numerical model to assess the vibration characteristics of an existing slender composite footbridge induced by human running load is presented. The aim is to evaluate the serviceability requirement of the structure against the current design standards. The footbridge vibration response is investigated using the finite element software SAP2000 through a series of analyses in terms of critical acceleration, displacement and velocity. For model verification, the first natural frequency acquired in this investigation has shown good agreement with the value reported in literature. It is found from the current study that the maximum acceleration of composite footbridge due to an average one person running excitation load is 0.15%g. Moreover, the maximum vertical displacement at the mid span is obtained as 0.5495mm, which is much lesser than the standard displacement limit (22.5mm). In other words, the current study has shown that the investigated structure offers human safety and comfort against vibration due to load induced by human running.