PSI - Issue 44

Laura Gioiella et al. / Procedia Structural Integrity 44 (2023) 1808–1815 Laura Gioiella et al. / Structural Integrity Procedia 00 (2022) 000–000

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1. Introduction Schools should be safe places where children and young people are hosted during their training years to develop their abilities and skills and to receive an education that make them prepared to become the future of the nations where they live. Even though these aspects are of paramount importance and widespread recognized, as stated in the GADRRRES (2017) report, the same importance does not seem to be ensured to school facilities. Educational institutes, indeed, are often old and realized without recent safety Standards, becoming consequently non-resilient, nor robust structures towards multiple natural hazards. To a national scale, Italy that is known to be an area prone to natural hazards like earthquakes or hydrogeological phenomena, is characterized by a school building heritage where more than 60% of the facilities were built before 1974, Ecosistema Scuola (2018), which means without seismic standards. The recent 2016 seismic sequence, sheds further light on the topic of the safety and resilience of public buildings and cultural heritage, due to the widespread damages recorded (Romis et al. 2021, Puncello et al. 2022). Moreover, it is quite frequent that retrofit interventions are promoted only after the occurrence of natural hazards, therefore operating in a reaction rather than prevention terms, as occurred for example after the Molise earthquake (2002). This event caused the death of 27 people after the collapse of a school building and leaded to the consciousness of the need of improving the safety of public buildings. Since that episode a new Standard, OPCM 3274 (2003) that adopted the philosophy of modern international seismic standards, has been introduced and many studies have been produced focused on the safety of schools and the study of their vulnerabilities like Dolce (2004), Di Ludovico et al. (2019a), Di Ludovico et al. (2019b) and Perrone et al. (2020). This paper focuses on the construction of a database of the schools located into the Marche region to which apply the probabilistic response model proposed by Morici et al. (2020) for the evaluation of the seismic damage of historical churches during the 2016 seismic sequence. The database of the schools has been built up combining basic information on school buildings provided by the Italian Ministry of the Education, the post-event surveys of damage reported in the so called AeDES forms, the shacking maps elaborated by National Institute for Geophysics and Volcanology (INGV) and providing the seismic intensity at each school location. The probabilistic model applied, relates a measure of the ground motion intensity to an overall damage index d , continuous in the range [0,1], where d =0 means no damage and d =1 means collapse. Moreover, if one integrates the partial information related to damaged buildings often provided by the post-earthquake surveys, with the data related to the undamaged and/or collapsed structures, the model can provide a full risk assessment procedure. In this study the parameters of the model, providing the expected damage, are fitted through inference techniques with reference to the schools located in the nearby of the epicentres of the main shocks of 2016. Finally, fragility curves of damage have been deduced from the probabilistic response model obtained inferring data, in order to facilitate the evaluation of risk based on PEER approach, Porter et al. (2002). 2. Empirical data acquisition: the built up of the database of the schools of the Marche region In this section, the construction of the database of the Marche region school buildings together with a brief description of the 2016 Central Italy seismic sequence and the post-earthquake surveys acquisition is described. 2.1. The database of schools of the Marche region Three different sources of information have been compared and merged for the realization of the database of the schools located in the Marche region. Such sources are: • school building registry of 2005, integrated with the data of the National System of the School Building Registry (SNAES), relative to 2016. • Shake Maps provided by the Italian National Institute of Geophysics and Volcanology (INGV). • Accessibility and Damage in Seismic Emergency (AeDES) forms, provided by the Reconstruction Office of the Marche region. In detail, the school building registry and the SNAES contain basically information on the building properties (no. of floors, floor surface, construction period, structural typology), the geolocation and the potential presence of