Seismic Reliability Maps of Code-Compliant Italian Reinforced-Concrete Bare and Infilled Frame Buildings

The present study illustrates the main results of an extensive campaign of numerical simulations aimed at quantifying the seismic reliability of reinforced concrete (RC) bare and masonry-infilled frames compliant with the current Italian Building Code. For this purpose, a set of different residential-use archetype structures are considered, and a prototype seismic design-assessment tool is created to quantify their performance with respect to the relevant limit states, deriving fragility curves via the execution of several non-linear time-history analyses (NLTHAs). The fragilities are subsequently combined with the hazard curves derived for each of the over 8000 Italian municipalities based on the national seismic hazard model currently in force to obtain the respective seismic mean failure rates across Italy. The seismic reliability maps obtained for the investigated code-compliant designs highlight how the current Italian Building Code fails to provide uniform seismic safety across Italy, showing-on the contrary-a strong hazard-dependency. The results are finally used to calibrate regression laws able to correlate the seismic mean failure rates with an intensity measure representative of the seismic hazard.