Proposal of an expeditious procedure for the seismic vulnerability analysis of masonry structures

The assessment of the structural vulnerability for existing buildings in Italy is a key aspect for the seismic risk reduction, for strategic and relevant buildings in particular, because of their importance for the civil protection. Different approaches can be used: expeditious/empirical methods, based on qualitative evaluations, analytical methods, based on detailed models, or hybrid methods, based instead on simplified numerical models. In case of a wide sample of buildings, the use of empirical methods is necessary in order to obtain a first screening of the buildings and 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, G.N.D.T., 1993) and a detailed approach (pushover analysis performed with the “Frame by Macro-element” approach) on a sample of 32 masonry structures is carried out. The critical analysis of the results has allowed the upgrade of an empirical assessment procedure recently proposed by the Authors, able to estimate the peak ground acceleration of capacity of masonry structures, using the information required by the II Level Vulnerability Form.