Preliminary study on the impact of the introduction of an updated seismic hazard model for Italy

A new hazard model for Italy has recently been proposed; hazard maps have been produced for various return periods, allowing the values of peak ground acceleration (PGA) and spectral accelerations for response periods up to 2 s to be interpolated for each of the 8,101 Italian municipalities. The new model allows for a more refined definition of the hazard in each municipality as compared to the current use of a fixed spectral shape anchored to upper bound 475-year PGA values and scaling factors for different return periods. The aim of this work is to investigate, in a preliminary fashion, the implications that the adoption of the new return-period dependent hazard maps would have on design and assessment of structures. To this end, the seismic performance of reinforced concrete frames of varying height is evaluated assuming they were located in each of the 8,101 municipalities in Italy and the results obtained with the current and the new hazard model are compared. The new model is shown to result in lower seismic risk in the majority of the municipalities