سال انتشار: ۱۳۹۱

محل انتشار: نهمین کنگره بین المللی مهندسی عمران

تعداد صفحات: ۶

نویسنده(ها):

Mohammad Jafari – M.Sc student, University of Tehran
Amir Keyvan Ghorbani-Tanha – Assistant professor, University of Tehran

چکیده:

In the past few years the issue of excessive footbridge lateral vibrations attracted great attention. There are three possible mechanisms that stand for lateral vibration; direct resonance, dynamic interaction, and internal resonance. This paper investigates direct resonance which is activated if the pedestrian excitation is in resonance with a specific mode of vibration. A single double-foot force model for the lateral component of force is employed. Based on it, the footbridge random load, in which pedestrians are modeled as loads interring the footbridge with average time intervals, is modeled. In this model, a stochastic approach is employed to calculate the acceleration power spectral density in any arbitrary position of the footbridge. Resonant effects are observed when the footbridge natural frequencies fall within the frequency range of crowd excitations. To suppress the excessive acceleration for human normal walking comfort, the application of tuned mass damper system, is shown to be satisfying