SIMPLIFIED PROBABILISTIC SEISMIC ASSESSMENT OF INFILLED REINFORCED CONCRETE FRAMES

Reinforced concrete (RC) frames with masonry infill are a popular structural system in many parts of the world, however still vulnerable, since a large number of infilled RC buildings collapsed during recent strong earthquakes. Therefore, any method for analysis of such buildings should properly take into account the highly non-linear behaviour of this system during strong earthquakes. Recently, a simple nonlinear seismic analysis method (N2 method), based on pushover analysis and inelastic spectrum approach, has been extended in order to make it applicable to infilled reinforced concrete frames. The N2 method can be, in combination with predetermined data on dispersion typical for a specific structural system, employed in the PEER probabilistic framework. By employing the simplest form of PEER probabilistic framework, the mean annual frequency of exceedance of a given performance level can be easily determined. In the paper the method for a simplified probabilistic seismic assessment of infilled reinforced concrete frames is briefly summarized and applied for a seismic assessment of a 4-storey infilled reinforced concrete frame, which was pseudo-dynamically tested in full-scale in the ELSA laboratory. The mathematical model of the infilled frame was validated by the test results. The results indicate that the probability of exceedance of the near collapse limit state exceeds the acceptable probability of exceedance.