Uncertainty propagation in serviceability assessment of footbridges

The paper deals with the propagation of uncertainties inherent to structural and loading parameters on the serviceability assessment of footbridges. Based on the equivalent spectral model, the standard deviation and maximum value of the footbridge acceleration are expressed as a function of the probability distribution of the step frequency and of the modal properties of the footbridge. The assessment of the propagation of uncertainties in the characterization of such parameters is carried out using the Taylor expansion method. The results are discussed and compared with conventional verifications, based on deterministic evaluations.