The Dynamic Behaviour of the "Erlebnisbrücke" on the BUGA in Ronneburg

The German Federal Garden Exhibition BUGA will be held in 2007 in the Thuringian towns Gera and Ronneburg. The most outstanding structure on the exhibition area is a 225 m long footbridge, the “Erlebnisbrücke”. This structure is a three span stress ribbon bridge with a timber superstructure. Several resonances in the range of typical step frequencies of pedestrians became obvious already during the design stage. Therefore the dynamic behaviour of the bridge and its response to dynamic loading generated by pedestrians were extensively investigated both experimentally and numerically. The predicted response amplitudes exceeded the values recommended in the codes. However, experience with large numbers of people on the bridge showed a good performance of the bridge under dense pedestrian loading. Nevertheless, the dynamic behaviour of the bridge will be observed carefully under service conditions. The installation of tuned mass dampers is considered as an option for the case of an unsatisfactory dynamic behaviour of the bridge.