ABSTRACT
Footbridges are amongst the structures that most strongly impact their users. This is consequence of their smaller scale when compared to roadway and railway bridges, as well as their function, which implies a long interaction with users during walking/ jogging or even rambling along their length. In addition, more and more often these structures are built, not only with the single purpose of creating a walking path between two points, but as pieces of architecture that mark the landscape and contribute to an added fruition of the travel. The typically small design loads and the modern trend to optimising materials, minimising dimensions and achieving longer spans, have resulted, in recent years, in the construction of daring footbridges, marked by very high slenderness and low weight. Modern footbridges have reached spans of more than 200m. These structures are normally characterised by high flexibility, relatively low natural frequencies and low damping, therefore being prone to vibrations induced both by the wind and by the action of pedestrians.
