Seismic risk of businesses with economic resilience and cost-effectiveness of seismic retrofit

Recent earthquakes in Italy have highlighted the importance of the risk assessment and management for productive activities, due to business interruption (BI) costs. In order to estimate this risk properly, both direct (repair/replacement) and indirect (BI) losses should be quantified. A recent study, calibrated on a real case study - a biomedical packaging company damaged by the 2012 earthquake in Emilia Romagna, Italy, which suffered direct damages and indirect losses and resumed business soon after (Donà et al. 2019, [1]) - has shown the significant impact of possible business recovery strategies in reducing the BI losses and thus the company's exposure for the various damage states (defined as in HAZUS-MH MR4, 2003). In this paper, a parametric seismic risk assessment is presented for businesses with an exposure model equal to that obtained by [1] for the real case study, analyzing and comparing various types of structural vulnerability (from HAZUS 2003), seismic hazard and business recovery strategies. The risk estimates were then used to assess the economic justification of the seismic retrofitting of existing RC factories (not seismically damaged), through the discounted payback period of the investment, with respect to the vulnerabilities, hazards and recovery strategies examined. In low-to-medium seismic areas, retrofitting may or may not be cost-effectiveness depending on whether recovery strategies are considered or not. Finally, these estimates on the retrofit effectiveness, which take into account the effects of recovery strategies, are used to address a possible breakdown of the retrofit costs between the company that rents the factory and the building owner, which can be used as reference when the intervention is globally cost-effective and desired by both parties.