Evaluating the vertical vibration response of footbridges using a response spectrum approach

In this paper, the vertical vibration response of footbridges subjected to dynamic loads induced by walking humans is assessed via a response spectrum approach. The dynamic walking load in the vertical direction is applied on the bridges using two different loading schemes: (1) a stationary load at the mid-span and (2) a moving load across the bridge. The response spectrum analysis is carried out using a Generalized Single Degree of Freedom procedure which has been verified by comparing its predictions with the results of a Multi-Degrees of Freedom modeling. The results obtained indicated that the response spectrum approach is capable of accurately predicting the footbridge vibration response. The results obtained also indicated that the main parameters that affect the induced accelerations in footbridges due to the human walking loads in the vertical direction are the footbridge mass and damping ratio.