Application of the SP-BELA methodology to RC residential buildings in Italy to produce seismic risk maps for the national risk assessment

Abstract

This article deals with the application of an analytical methodology for the large-scale vulnerability assessment of reinforced concrete frame buildings in Italy. This methodology is known in the technical literature with the acronym SP-BELA (Simplified Pushover-Based Earthquake Loss Assessment) and has been adopted by the Eucentre research group to contribute to the production of the seismic risk maps in Italy, published in the National Risk Assessment document. The Italian maps were elaborated using the IRMA platform (Italian Risk MAps), which is a web platform developed by Eucentre. The IRMA platform is only addressed to the scientific community who can use it to share data, methods, and models for the evaluation of the seismic risk in Italy (Borzi et al. in Piattaforma IRMA Italian Risk MAps, 2018; Dolce et al. in Mappe di rischio per il territorio Italiano, 2019a; Faravelli et al. in Italian platform for seismic risk and damage scenario evaluation, 2019a, Borzi et al. in Bull Earthq Eng, 2020, Dolce et al. Bull Earthq Eng, 2020). SP-BELA defines the non-linear behaviour of a random population of buildings through a simplified pushover and a displacement-based procedure. Specifically, displacement capacity limits are identified on the pushover curve and then they are compared with the displacement demand from a response spectrum of each building in the random population. In this way, it is possible to define the probability of exceedance of the damage limits and hence generate the fragility curves. Then, the resulting curves have been calibrated by comparing the damage data observed on the reinforced concrete buildings with the damage analytically calculated with SP-BELA for the earthquakes of Molise 2002 and L’Aquila 2009. The final curves have been uploaded into the IRMA platform and used to produce damage maps for the entire national territory.