RELATION BETWEEN DYNAMIC RESPONSE AND THE TRAFFIC COMFORT OF SOME FOOTBRIDGES ON PLATE GIRDERS

ABSTRACT

This paper presents several issues regarding the dynamic behaviour of the pedestrian footbridges structure under the action of general loads generated by the pedestrians’ displacement, together with the correlated traffic comfort of the pedestrians crossing the structure. The footbridge crossing comfort criterion requires the inclusion of vibration frequencies and accelerations of the structures in certain limits so that the vibration amplification or resonance is avoided. The paper puts under investigation six footbridges on steel or composite steel-concrete girders from the viewpoint of frequencies in vibration Mode 1 in a vertical plane, originated in their own weight (natural frequency) or from a partial loading, in the frame of traffic class III, as well as the resulting resonance risk and the traffic comfort, respectively.

Keywords: footbridges, traffic comfort, dynamic response, critical frequency and acceleration, practical analysis of footbridges