In this paper the development of an analytical vulnerability assessment procedure for Reinforced Concrete (RC) buildings is presented, which starting from a simplified model of the building based on the assumption of a Shear Type behaviour can provide a large scale seismic vulnerability assessment of RC buildings, considering the presence of infill elements. In this regard, when evaluating the influence of infills on the seismic response of RC buildings, the interaction between infill panels and structural elements develops at global level, leading to an increase in lateral stiffness and base shear capacity, but also at local level, potentially leading to brittle failure mechanisms in surrounding elements such as columns or beam-column joints. In this work attention has been focused particularly on the second aspect and hence efforts have been made to evaluate the displacement threshold identifying the incipient brittle collapse due to interaction between infill panels and surrounding frame under seismic action.

Moreover the up-to-date post-earthquake observed damage data demonstrates how a reliable seismic vulnerability assessment cannot disregard these factors. Hence the results of the procedure, considering or not interaction between infill panels and RC structural elements, are compared with those of empirical methods, in which the assessment of expected damage for a given building typology is based on the observation of damage suffered during past seismic events.