SEISMIC DAMAGE OF EXISTING SIMPLY SUPPORTED RC BRIDGES

摘要

Recent earthquakes around the world show a pattern of steadily increasing damages and significantlosses to civil infrastructures. The estimation of losses resulting from earthquakes, i.e. the seismicrisk, has been the focus of earthquake engineering research for many years. In Italy, this topic is atopical matter, especially after the becoming effect of new Italian seismic code [1], [2], [3], thatacknowledge the most recent analysis methods, the last standard seismic design and supply retrofitmethod for existing structure. This paper is developed around this last subject, to be more preciseon the analysis of expect seismic damage for existing structures in Italy with special regard forbridges. Therefore a simple and quick procedure has to be made to evaluate the seismicvulnerability of these structures. The common vulnerability of multi span simply supported bridgesis considered; these types of bridges are the most common in Italy. For these kinds of structures theseismic vulnerability is closely related to the damage of pier and the possible fail of superstructurepierconnection. Probabilistic approach is assumed in this paper, coherently with the uncertainnature of seismic event and the fragility curves have been adopted to evaluate the seismicvulnerability. The convolution between fragility curves and hazard curve provide the expectedseismic damage for a set state limit.