Seismic vulnerability analysis for reinforced concrete structures through simplified and detailed approaches

The assessment of the structural vulnerability for existing buildings is a key aspect for the seismic risk reduction. Different approaches can be used: expeditious/empirical methods, based on qualitative evaluations, or analytical methods, based on detailed models. In case of a large sample of buildings, the use of empirical methods is necessary in order to delineate a vulnerability ranking, which can be used as a priority list for further detailed analyses. In this work, the comparison among an empirical approach (Vulnerability Index Method, GNDT, 1993) and a detailed approach (static non-linear analyses) on a sample of reinforced concrete structures has been performed: some of them are existing buildings, others are simulated in order to reproduce the characteristics of the load bearing design technique. The critical analysis of the results has allowed the development a correlation among the approaches, able to estimate the structural capacity of the buildings (in terms of PGA) using the information required by the empirical method.