Numerical and experimental lateral vibration assessment of an in-service footbridge

Abstract

This paper describes the experimental and numerical lateral vibration assessment of La Paz footbridge (LPF) as part of a research project of pedestrian structures located in Madrid. LPF is a cable-stayed structure with main span of 85m and total length of 127.8m. A preliminary analysis predicted a first lateral mode close to 0.9Hz, which is within the critical range and, consequently, a further analysis was required. The numerical assessment was performed in the frequency domain and the pedestrian action was defined using the HIVOSS guide. The experimental evaluation consisted in both the modal testing of the structure to validate the numerical model, and interaction pedestrian tests. The numerical model is in accordance with the tests and thus the footbridge dynamics is accurately determined. However, the interaction pedestrian tests are not sufficient to evaluate the LPF performance under dense traffic conditions.