ABSTRACT
Modern footbridges are built thin and slender as a result of technical innovation and more accurate structural analysis. As a consequence, a new problem related to vibrations caused by loading pedestrians has been discovered.
Two modern footbridges have experienced vibration problems due to pedestrian loading at the beginning of his life: 1) the Millennium footbridge in London and 2) the Solferino footbridge in Paris. The two bridges were closed shortly after opening, due to lateral swaying from pedestrians, in order to solve the problem. Many researches on the area of vibrations induced by foot traffic have been made after this.
In slender footbridge design, human-induced loads are significant. The dynamic effect of the pedestrian load can cause uncomfortable and excessive vibrations due to its low frequency, being able to give rise to the phenomenon of resonance in slender and flexible footbridges with low natural frequencies in the same order as the pedestrian load.
This paper presents some design recommendations about the dynamic calculations of footbridges and exposes a short dynamic calculation of an arch footbridge of 30 m s with the help of the LUSAS software.
