Role of design level and infill arrangement on the seismic fragility curves of Italian RC existing buildings

Assessing the seismic vulnerability of existing buildings is a fundamental step in order to define mitigation programs in prone earthquake areas. In Italy, in 2019 the National Department of Civil Protection supported an ongoing research project involving its “Center of Competence” on seismic risk, ReLUIS (Network of University Laboratories for Earthquake Engineering), with the cooperation of Eucentre (European Centre for Training and Research in Earthquake Engineering) to update the 2018 version of the National Risk Assessment. In this context, new fragility curves are being derived by using different approaches, whose results will be properly combined. In the paper, the purposely set up methodology for deriving analytical fragility curves through Non-Linear Dynamic Analyses (NLDAs) has been described. Further, results relevant to some Italian Reinforced Concrete (RC) building types have been shortly presented and analyzed, emphasizing the role of some key parameters affecting seismic vulnerability such as design level and infill arrangement.