A direct pedestrian-structure interaction model to characterize the human induced vibrations on slender footbridges

The phenomena of interaction between pedestrians and structures are known since, at the end of the 19th century, a group of 60 soldiers excited, under its step, a bridge located in the British town of Broughton [1]. Although the scientific community didn't stop studying the above mentioned phenomenon, it wasn't up to the occurrence of the phenomenon happened in the Millennium Bridge (London) [2], when the importance of the problem has produced a high level of attention. Large advances have been realized, from the above mentioned date, in the characterization of the interaction force that takes place between pedestrians and footbridges during the step of a pedestrian flow [3]. The above mentioned efforts in the characterization of the phenomenon, together with the increasing need of the current society for the construction of this type of structures, as way of structuring the urban spaces that surround cities, have been reflected in the appearance of investigation projects [4] and specific normative codes [5] for the consideration of the above mentioned phenomenon. In this paper, the formulation of a human-structure interaction model is carried out and its reliability is verified from the measures made on a footbridge when a controlled group of pedestrians circulate on it.