PSI - Issue 44

Marta Faravelli et al. / Procedia Structural Integrity 44 (2023) 107–114

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Marta Faravelli et al. / Structural Integrity Procedia 00 (2022) 000–000

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1. Introduction

Recent seismic events that occurred worldwide clearly demonstrated the seismic vulnerability of school buildings ( e.g., Azizi-Bondarabadi et al. 2016, Gautam et al. 2020). In Italy, the issue has been highlighted by various seismic events, like San Giuliano di Puglia 2002 (Augenti et al. 2004) and the Central Italy 2016/2017 (Di Ludovico et al. 2019a,b), just to mention some emblematic cases. That calls for an urgent need of tools able to support the development of effective mitigation policies ( e.g ., Grant et al. 2007, WISS 2013, UNISDR 2014), as testified also by various studies addressed to enhance resilience of schools (Gonzalez et al. 2020, D’Ayala et al. 2020). Moreover, the need of derivation and periodically update the national risk assessment for school buildings is coherent with EU decision 1313 (2013) and responds to the specific requirement of the “Sendai Framework for Disaster Risk Reduction 2015–2030”. Within this context, the Italian Civil Protection Department (DPC) conveyed the effort of several Italian Universities and EUCENTRE to update the National Risk Assessment already released in 2018 (NRA 2018, Dolce et al. 2021) for residential buildings, in order to include other strategic assets, such as schools. Thus, within the 2019– 2021 research agreement between the DPC and the Network of University Laboratories for Earthquake Engineering (ReLUIS), the work package WP4 “Seismic Risk Maps -MARS” has been specifically conceived to address this scope (Masi et al. 2021), with the collaboration of EUCENTRE. One of the aims of the project is the derivation of seismic fragility models able to describe the vulnerability of classes of schools characterized by seismic homogenous behaviour (Cattari et al. 2021, Cattari et al. 2022, Di Ludovico et al. 2022). However, once fragility curves that describe the behaviour of school buildings are available, a platform that implements them is essential to finalize risk assessment. Therefore, effective tools are needed for decision-makers able, on one hand, to provide an overall picture of the entire territory and, on the other one, to support comparative assessments in order to target the allocation of risk mitigation funding. Several research groups around the world have developed tools to carry out seismic risk assessments to estimate earthquake damage and losses for residential buildings. Some examples are constituted by the open source OpenQuake engine developed within the context of the Global Earthquake Model (Silva et al. 2014) or the SELENA approach proposed in (Molina et al. 2010) and based on the well-known HAZUS methodology (FEMA 2003), just to mention a few. In Italy, the IRMA (Italian Risk MAps) platform was previously developed for performing the NRA 2018 of Italian residential buildings; it allows the sharing of data, methods, and models aimed at seismic risk assessment (Borzi et al. 2018, Borzi et al. 2021). Then, the platform IRMA has been further developed in MARS with a specific tool dedicated to the evaluation of seismic risk maps for school buildings at national level. The following sections describe the inventory that defines the exposure of the Italian school building (§2), the structure of the IRMA-Schools tool (§3), and the calculations it performs for seismic risk assessment (§4). 2. Inventory of Italian school buildings At this stage of the research, the platform IRMA adopts the inventory of school buildings set up by the Ministry of Education in 2005. Although data for many schools (mainly related to specific areas) are incomplete, 49,531 buildings throughout the Italian territory are included in the inventory, as shown in Figure 1. The inventory collects both administrative information (e.g. name, address, level of school) and some typological parameters (i.e. structural material, period of construction, number of storeys, floor area, type of vertical/horizontal/roof structures). It is worth highlighting data are collected by non-technician operators. In order to provide a synthetic overview on exposure data available, in Figure 2 some data analyses are plotted. Besides a large amount of buildings for which structural material information is not available (about 31%), most of school buildings consists of reinforced concrete (RC, about 31%) and masonry structures (about 21%). Other types, such as mixed, steel and wooden structures, amount to about 17%. RC buildings were mainly made up starting from the ‘60s while most of masonry buildings dates back before the ‘60s. Both RC and masonry school buildings have mostly 1 (about 33% for RC and 25% for masonry buildings) and 2 storeys (about 40% for RC and 47% for masonry buildings) in elevation with a prevalence of floor area lower than 500m 2 for masonry buildings (about 45%) whereas, for RC ones, similar percentages (in the range of 25-30%) are found for <500m 2 , 500-1000m 2 and 1000-2000m 2 categories.