Abstract
This paper presents a damage evaluation method of RC structures based on a reduction ratio of natural freqency. An ambient vibration monitoring was conducted on full-scale bridge column specimens constructed for a shake table project using E-Defense. The damage levels after the seismic excitations were classified into the safety, the yield, and the ultimate states from the response ductility. The reduction ratios of natural frequency caused by the seismic damage were obtained from the ambient vibration data. The relationship between the damage levels and the reduction ratios of the natural frequency were clarified. The evaluation of the safety, the yield, and the ultimate states can be realized by the combination of the ambient vibration monitoring and visual inspection.
