Investigation of dynamic responce of cable-stayed footbridge

Abstract

This report examines the dynamic behavior of a cable-stayed steel footbridge over the River Neris in Vilnius, Lithuania. Intensive vibration of the bridge subject to a large number of pedestrians had been observed when it was open to the public. Improvements were achieved by adding tie-down cables that were intended to suppress the bridges' vibrations. The objective of this study was to investigate free, forced and ambient vibrations of the bridge and influence of the added vibration absorbers. In-situ tests were conducted to observe the effectiveness of the suppression measures. In the theoretical study, vibration parameters were determined by using a finite-element method. This study shows that vibration absorbers change the natural frequency approximately from 10-15% and decrease the amplitudes of the deck up to 1.5 times.