DYNAMIC RESPONSE OF CABLE STAYED STEEL BRIDGE WITH TUNED MASS DAMPER INSTALLED - NUMERICAL AND EXPERIMENTAL APPROACH

The paper describes the detail dynamic calculation of cable-stayed footbridge structure with comparison of dynamic measurement. The footbridge has natural frequencies that coincide with the dominant frequencies of the pedestrian-induced load and therefore they have a potential to suffer excessive vibrations under dynamic loads induced by pedestrians. Some of the design standards introduce load models for pedestrian loads applicable for simple structures. Load modeling for more complex structures, on the other hand, is most often left to the designer. An attempt to model the load imposed by a single person and a crowd of pedestrians resulted in displacements and accelerations that are compared with serviceability criteria. Because the first stage of dynamic calculation concludes that serviceability criteria aren't discharged, the tuned mass damper (TMD) needs to be installed. The structure was finally measured and natural frequencies and shapes were obtained. Also under various dynamic actions the transient responses of the structure with and without TMD active were performed.