PSI - Issue 78

Paolo Petrella et al. / Procedia Structural Integrity 78 (2026) 2062–2069

2063

1. Introduction Reuse of a heritage building can often be an opportunity for its conservation. Today there is a lot of talk about adaptive reuse, see Girard and Gravagnuolo (2025) with bibliography. The subject of the paper concerns a heritage building that is being reused with the content for which it was originally built, that is a school building, but reuse is done by adapting the construction to the safety of a new building while ensuring the preservation of historical value. Italian code NTC (2018), referring to the "Codice dei beni culturali e del paesaggio" (Code of Cultural Heritage and Landscape) (2004) establish that "for assets of cultural interest falling within earthquake prone areas, it is in any case possible to limit project to improvement works by carrying out the relative safety assessment". According to this specification, present project concerns a seismic improvement intervention, even if the achieved seismic safety coefficient is equal to 1,033 and configures the achievement of a state of full seismic retrofitting (adaptation). For the design of the interventions, reference is made to the LV3 evaluation level (improvement intervention) envisaged by the Direttiva (2011), which concerns the design of interventions widespread in the construction, but which in principle do not modify the structural functioning already ascertained through the knowledge path. The assessment concerns the entire construction and was carried out using a global structural model, considered reliable for the purposes of the needed evaluations. To assess seismic safety, nonlinear static analyses (pushover) were carried out on the structure in post-operam conditions, which allow determining the safety value of the construction achieved with the improvement works. For a cultural asset, according to the NTC (2018), the achievement of a pre-established level of safety is not required, but in reality the owner specifications provide for the achievement of a post-operam seismic safety coefficient, assessed in terms of PGA capacity/demand ratio, higher than 0,66 and also provide for a bonus based on the increase of this coefficient above 0,66. Actually the Direttiva (2011) would even allow, in the event that the interventions required by the adaptation were to be too invasive with respect to the building, to refer to a shorter nominal life of the asset. In this project, considering the safety needs connected to the use of the building as a school and the expectations of citizens with regard to school buildings, it was decided not to reduce the Nominal Life of the building and to carry out the assessments with the same safety rules as a newly built school building, considering a Reference Life VR equal 75 years. In any case, the interventions adopted, although compatible with the protection of the historical and monumental value of the building, have allowed the actual adaptation of the structure to be achieved. 2. Subject of intervention The project concerns the seismic improvement of the building that houses the “Ovidio” Classical High School, located in the Municipality of Sulmona (AQ) in Italy. The building (Fig. 1) has an almost rectangular plan, with dimensions of approximately 56 x 50 m, with a maximum height of 12,45 m. The facades are characterized by large windows, crowned by architectural friezes, which clearly highlight the vertical structural elements and provide the necessary natural lighting both to the rooms and to the large corridors that run around the perimeter of the entire structure. All the internal spaces, of regular shape, are occupied by the various activities consistent with the teaching and management of the school complex. The building was built in the 17th century and during its life it has been the subject of numerous reorganization and renovation interventions. The current appearance of the building is due to the significant and radical renovation that took place around 1925-1930, following the great earthquake of 1915. The building is irregular both in plan and elevation, presenting a non-homogeneous distribution of the load bearing structures that extend over two floors above ground, with an additional basement and an inspectable attic. The load-bearing structure is made of disordered stone masonry, with squared stone corners. The portico of the internal courtyard is made of r/c on the ground floor and solid brick masonry on the first floor. The elevation stories are characterized by floors made of concrete and hollow bricks and floors made of iron beams and hollow bricks; the basement is characterized by floors made with stone barrel vaults. The roof, partly hipped and partly gabled, is made of load-bearing structures in solid wood with trusses, main beams, with planking and tiled roofing.