Application of the pseudo-excitation method to assessment of walking variability on footbridge vibration

• The pseudo-excitation method is adapted to footbridge vibration.
• A simple spectral model is proposed and shown give similar results to those in the literature.
• Monte Carlo simulation is used to verify the approach.
• It is shown to be computationally efficient and accurate for the problem.
• Small deviations from ideal walking are shown to significantly reduce vibration response.

The pseudo-excitation method is applied to determine the non-stationary vibration response of footbridges to variable pedestrian excitation. Excitation forces are described by their spectral densities, the models of which are taken from the literature. In addition a simple spectral model is proposed to encompass both intra- and inter-pedestrian variability. Comparison is made to Monte Carlo simulations of random pedestrian events and a means of estimating extreme statistics of random walking is given. The method is shown to be accurate and efficient. Consequently, this work should find value in explaining differences between observed and modelled responses.