Vibration-Based Damage Detection and Seismic Performance Assessment of Bridges

This paper proposes a reliability estimation methodology which utilizes system identification results obtained from vibration measurements. A series of earthquake and white noise excitations are imposed to a three-bent reinforced concrete bridge by three-shaking tables, simultaneously. Progressive structural damage is measured and observed, in accordance with increasing intensities of damaging events. Response measurements are obtained by accelerometers located on the deck and the columns of the bridge. Finite element models for non-updated and updated cases were obtained with and without considering acceleration measurements, respectively. Afterwards, damage detection and reliability estimation were carried out for these two cases using fragility curves. Consequently, it is shown that fragility curves of updated models significantly differ from fragility curves of non-updated models. The distinction stems from the difference between stiffness and especially damping parameters of updated and non-updated models. Such difference becomes more prominent at the extreme levels of damage.