Influence of Infill Presence and Design Typology on Seismic Performance of RC Buildings: Fragility Analysis and Evaluation of Code Provisions at Damage Limitation Limit State

The same case study structures of the companion paper (Ricci et al., 2012) are analyzed. Seismic capacity at different Limit States is assessed by means of Static Push-Over analyses, within the N2 spectral assessment framework. Fragility curves are obtained, through the application of a Response Surface Method. Seismic performance is also expressed in terms of failure probability, given a reference time period. Italian code provisions for seismic assessment at Damage Limitation Limit State are discussed: code allows to take into account the presence of infills - if a bare numerical model, as usual, is used - by assuming a fictitious displacement capacity limit (e.g., 5‰ Interstorey Drift Ratio); code also allows to limit the maximum Interstorey Drift Ratio in a Reinforced Concrete structure to values related to masonry (e.g., 3‰ for unreinforced masonry) if infills are explicitly taken into account in the structural model. The conservatism of these provisions, depending on the number of storeys and the design typology, is analyzed.