F. Venuti, PhD student, L. Bruno, Associate Prof., P. Napoli, Full Prof., Department of Structural Engineering and Geotechnics, Politecnico di Torino, Torino, Italy.

This paper proposes a new load model to predict the lateral force exerted by pedestrians walking on lively footbridges. The aim of the model is to take into account some important features of the synchronous lateral excitation phenomenon, which so far has not been fully understood or modelled, e.g. the distinction between synchronization among pedestrians, due to crowd density, and between the pedestrians and the structure, caused by deck oscillations; the triggering of the lock-in phenomenon and its self-limited nature. The proposed load model has been tested with reference to two crowd events that were recorded on the T-bridge in Japan (1993) and on the Millennium Bridge in London (2001). The results obtained with the present model are compared to results predicted by other load models found in literature and are then discussed.