| Resumo: |
The aim of the project was the development of advanced load models for synchronous pedestrian excitation and to conclude the results in optimised design guidelines for steel footbridges.
Based on extensive measurements on a test rig a practical and simple spectral load model was derived that can be used for the determination of vibrations for sinusoidal mode shapes .Also a design load model for FEM calculations was developed that allows for different pedestrian densities and all types of mode shapes.
Measurements of vibration behaviour due to different pedestrian loadings on 9 different lively footbridges were used to check and verify the developed load models. Besides comfort questioning were conducted and synchronisation effects during events were investigated.
The most important outputs are several load models of different complexity and the design methodology. Due to the difference in complexity and depending on the design stage, the designer can choose the most adequate load model for his purposes.
As it is very difficult to specify unique comfort criteria thus it is recommended to define comfort criteria for each footbridge individually by considering expected traffic amount and location of the bridge. Therefore, a great flexibility in the design is allowed and relevant influence factors on loading and perception and judgement of vibration should be considered.
Clients and designers of footbridges have now a powerful tool (design guideline with various load models) to demand and predict the vibration behaviour of footbridges due to pedestrian traffic more accurately. |