Preliminary nation-wide risk-informed prioritization of existing strategic buildings: the role of input parameters

Recent earthquakes have highlighted the need for seismic risk assessment of existing strategic buildings due to their function in an integrated civil protection system. To support decision-making in seismic risk mitigation of large building portfolios, the prioritization of structural retrofit actions at national scale should account for limitations in intervention budget, knowledge, and cost of assessment. In this respect, seismic risk prioritization can benefit of nominal deficit measures that compare code requirements at the time of design to current seismic demand; e.g., using peak ground acceleration (PGA) as intensity measure. In this study, a procedure for nation-wide risk-informed prioritization of existing strategic buildings is preliminarily described. A number of nominal deficit measures is considered, accounting for current PGA demand evaluated through different hazard and local soil classification maps. The novelty, with respect to existing literature, is mostly in the consideration of the uncertainties in design year and minimum (inherent) seismic capacity of gravity-load- designed buildings. The procedure is preliminarily applied to a portfolio of strategic buildings, assessing the influence of the considered nominal deficit measures on the ranking and number of buildings for which upgrading- and retrofitting-related results necessary. In case of gravity-load-designed buildings, the impact of assuming different levels of seismic capacity is also evaluated.