Comparative analysis of the fragility curves for Italian residential masonry and RC buildings

Abstract

The Department of Civil Protection (DPC), in compliance with the EU decision 1313/2013 and at the request of the Sendai Framework for Disaster Risk Reduction 2015–2030 to update the disaster risk assessments by various countries, released the latest National Risk Assessment for Italy at the end of 2018. Specifically, as regards the seismic risk assessment, six research units belonging to two centres of competence of the DPC collaborated under its guidance to update the risk maps of the Italian residential heritage. This extensive collaboration complied with the recent Italian code for Civil Protection, which requires a broad scientific consensus for risk assessment. During this research activity, six fragility models were developed, according to some common criteria (four for masonry buildings and two for RC buildings). These models were then implemented by the DPC for the definition of the national seismic risk. Within this context, the aim of this paper is to evaluate the risk results provided by these models, compare their features, and assess and validate their prediction capabilities. In particular, this paper shows the comparison of predicted and observed damage scenarios and consequences on building stock and the population of two seismic events, i.e. L’Aquila 2009 and Amatrice 2016. Furthermore, the paper provides some interesting damage and risk predictions at a national level. Overall, the forecasts and comparisons made in this study demonstrate the validity of the approach adopted by the DPC for the assessment of national seismic risk.

CAESAR II Tool: Complementary Analyses for Emergency Planning Based on Seismic Risks Impact Evaluations

“…In the literature, there are many works related to risk analysis, either in a broad sense or to some specific factor. Some specific studies on the vulnerability can be found in [1][2][3][4][5][6][7][8][9][10] and on the exposure in [11,12] Regarding the costs analyses, some works are reported in [13,14] and on the multi-criteria, there are [15][16][17][18][19].…”

“…In the CAESAR II tool, the hazard parameter used is the PGA (peak ground acceleration), because of the availability of PGA-Level Damage fragility curves developed by the authors, whose reliability has been tested in other applications. Although hazard may be defined by different parameters relevant to seismic motions, such as spectral shape, duration and energy content, PGA has been chosen since it represents the most consolidated quantity used by the Italian community [1][2][3]5]. In this sense, the available PGA data sufficiently characterize the entire national territory, while the use of different parameters can result in less reliable analyses.…”

“…In the case of a 'scenario' analysis, the seismic event taken as a reference can be assumed through (1) an attenuation law as a function of some seismic parameters, such as the coordinates of the hypocentre and the magnitude value, or (2) a shaking map (ShakeMap). The distribution over the territory of the parameters that define the extent of a seismic event (e.g., the PGA) can be derived through the adoption of an attenuation law, as a function of other seismic parameters (usually the magnitude) and epicentral (or hypocentral) coordinates.…”

Intervention Strategies for the Seismic Improvement of Masonry Buildings Based on FME Validation: The Case of a Terraced Building Struck by the 2016 Central Italy Earthquake

“…Residential buildings account for 75% of the total stock in Europe, of which 64% consists of single-family houses, i.e., detached, semi-detached, or terraced houses (the rest being apartment blocks) [1,3]. In Italy, 87% of residential buildings correspond to masonry and reinforced concrete (r.c.)…”

Integrated Seismic and Energy Retrofit Interventions on a URM Masonry Building: The Case Study of the Former Courthouse in Fabriano

“…The latest seismic events affecting Italian territory revealed that the poor seismic performance of masonry buildings resulted in high damage and losses (i.e., central Italy, 2016 [1,2], including also the positive effects of preventive actions [3], Emilia 2012 [4,5], L'Aquila 2009 [6,7], Molise 2002 [8][9][10], and Umbria and Marche 1997 [11,12]). The recent seismic risk assessment of residential buildings in Italy also demonstrated the significant economic loss and loss of human lives connected to the performance of existing, and particularly masonry, buildings [13,14].…”