Vibration monitoring on a PC girder bridge during a bridge collapse test

Abstract

Using the information gathered from structural health monitoring (SHM) has been proved successful when identifying damage on specific type of bridges. However to know the extent of the localized damage into the structural performance or even the degree of its vulnerability by means of the SHM is still under discussion. This study aims to examine how changes in load resistance capacity of an actual PC girder bridge influence on their dynamic properties. In this study a real PC girder bridge under static loadings, a bridge collapse-test, is discussed. In the static loading test, the PC Bridge was put under several loading and unloading levels until failure. Besides, forced vibration tests from both impact hammer test and moving-vehicle test were carried out along the static loading test, in order to assess the changes in the dynamic properties of the PC Bridge with different health conditions. The study investigates the influence of different phenomena, such as creep and cracks propagation, on the variation of modal parameters. Observations showed that changes in the frequency of the second bending mode was more analogous with the changes of load resistance capacity than the first bending mode.