Modal properties of the old suspension footbridge based on ambient vibration measurements

Abstract

The paper presents study of dynamic properties estimation based on ambient vibration measurements of the old suspension footbridge over the river Vrbas in Banja Luka (in Šeher sub-area), Serbian Republic in Bosnia. Prone to uncomfortable vibrations under pedestrian excitation, so-called lively footbridge, was tested and few first modes of vibrations were identified by Frequency Domain Decomposition method. Measurement technique and layout of ambient vibration are presented. Analysis of estimated of modal parameters, modal frequencies and mode shapes, of the footbridge under everyday pedestrian traffic was carried out as a part of dynamic response analysis.