Vortex-induced vibration of stay cables, verification on the footbridge

Abstract

Long-span footbridges rank among engineering structures with a high social significance. Their architecture design must in general satisfy matters such as attractive look, reliability and light. These requirements predestinate the bridge to be sensitive to the wind effects and the assessment against the wind becomes crucial. One of the several wind phenomena occurring on such a type of structures is termed as the vortex shedding. This flow induced excitation lying in a periodic vortices separation may arise at low wind velocity on both the main parts of a bridge structure including bridge girder with pylons and additional members such as stay cables, hand railing, etc. According to the character and intensity of the excitations, the adequate treatment to reduce or avoid the oscillations should be given. It is also performed when the vortex induced oscillations do not influence the reliability of a footbridge, but the look at the amplitudes could start panic and could start vandal’s action – increasing the amplitudes.