PSI - Issue 78

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

2069

determines the box-like behaviour of the building, avoiding, thanks to the connection of the walls to the floors at floor level, the formation of first mode mechanisms associated with the effects of out-of-plane seismic actions. Angled and hammer connections of masonry piers The creation of bar reinforced holes is planned to reduce the deficiencies of the connections found between the masonry piers. These interventions are aimed at ensuring that the building has a satisfactory overall behaviour, through the widespread creation of a good bond between the walls. The creation of these interventions, together with those of connection between floors and walls, is an essential prerequisite for the application of the global seismic analysis methods of the building, which are based on the behaviour of the masonry walls in their own plane, assuming their stability with respect to seismic actions out of the plane, or first mode mechanisms. Steel hooping with L-profiles of openings in the load-bearing walls The presence of a high index of openings on all the walls of the building, both perimeter and internal, leads to a loss of strength and stiffness of the earthquake-resistant wall panels. To overcome this problem, it is planned to hoop some existing openings, both windows and doorways, which constitute the major critical points in the structure, through the insertion of steel profiles, typically L-shaped, of adequate dimensions, appropriately and effectively clamped to the top and side walls, in order to guarantee the correct distribution of the vertical loads. Insertion of steel “break -beams" for better distribution of the load deriving from the floors In some spans of the floors on the second level, due to their considerable spans, some steel beams (IPE 200) are not adequate to support the loads acting; it is therefore planned to reduce the span of some spans by inserting steel beams of adequate dimensions (IPE 400), to be effectively anchored both to the perimeter walls and to the aforementioned steel beams, in such a way as to create a single collaborating system from a structural point of view and to favour a better distribution of the vertical loads acting. Insertion of metal tie rods for floor stiffening with steel profiles The study of the three-dimensional model of the building has highlighted excessive relative displacements of the longitudinal walls of some rooms, essentially due to the lack of transverse connections between them. To reduce excessive deformations of the aforementioned walls and therefore create effective transverse connections, it is planned to insert metal tie rods with HEA 140 steel profiles, adequately sized and clamped to the perimeter kerbs, in order to favour the stiffening of the floor and the box-like behaviour of the structure in its entirety. Anti-tipping mesh in basalt fiber for partitions There is an absence of elements for fastening the partitions to the wall facings and therefore with the risk of total or partial tipping of the same. It is therefore planned to intervene to prevent the partitions from tipping, with their connection to the load-bearing walls, by means of connections made with a bidirectional basalt fibre mesh, impregnated with pure lime-based mortar and duly flocked. Dimensional check of the wooden roofing structures All the load-bearing structures in the roofing are checked promptly and adjusted and/or replaced where necessary. 4. Conclusions The design and the works made, and now concluded, to pursue the full seismic retrofitting of a heritage-protected building of the 17th century intended to house a school have been illustrated. On one hand, the works designed provide for not reducing the nominal life of the construction and for carrying out the safety assessments with the same rules as for a newly built building. On the other hand, the interventions adopted resulted and were judged fully compatible with the protection of the historical and monumental value of the building. References Codice dei beni culturali e del paesaggio, D.L. 22/01/2004, n. 42, ai sensi dell’art. 10 Legge 06/07/2002, n. 137. Direttiva P.C.M. 09/02/2011. Valutazione e riduzione del rischio sismico del patrimonio culturale con riferimento alle Norme tecniche per le costruzioni di cui al decreto del Ministero delle infrastrutture e dei trasporti del 14 gennaio 2008. G.U.R.U 26/02/2011. Girard, L-F., Gravagnuolo, A., 2025, Adaptive Reuse of Cultural Heritage. Springer. NTC - Aggiornamento delle «Norme Tecniche per le Costruzioni». D.M. 17/01/2018. G.U.R.U. 20/02/2018.