PSI - Issue 78

Cristoforo Demartino et al. / Procedia Structural Integrity 78 (2026) 2126–2132

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detailing, inadequate anchorage, and irregular geometries. This has resulted in significant structural failures during past earthquakes, including shear failures in columns, out-of-plane collapse of walls, and separation between building wings or expansions , Mitchell et al. 2011, D’Ayala et al. 2020 . Nonetheless, nonstructural components have proven to be equally, if not more, vulnerable in recent events. Their failure has contributed substantially to both physical injuries and the interruption of educational services. For example, the 2009 L’Aquila ea rthquake caused widespread nonstructural damage across over 600 school buildings, including the collapse of ceiling systems, detachment of infill panels, and damage to lighting and mechanical installations, D’Ayala et al. 2020, Di Ludovico et al. 2023 . In many cases, these failures occurred in otherwise structurally undamaged buildings, delaying reopening and requiring costly interventions. Nonstructural damage has also been shown to dominate economic losses in moderate seismic events. Performance based analyses applied to typical RC school buildings suggest that NSEs may account for 60 – 80% of expected annual seismic losses, especially in cases where equipment, finishes, or suspended elements are inadequately restrained, Aloisio et al. 2023, O’Reilly et al. 2018 . These findings are consistent with international studies highlighting the disproportionate impact of NSE failures in essential facilities such as schools and hospitals, Angelucci et al. 2023. Figure 2 shows the damage to the main structure and nonstructural components of a school building following the 2016 Central Italy earthquake. From a life safety perspective, the risk associated with nonstructural failures in schools is exacerbated by several factors: the presence of children and adolescents, the high occupancy during school hours, and the critical importance of clear egress routes. Moreover, given the role of schools as temporary shelters following earthquakes, the immediate post-event usability of these buildings is strongly influenced by the condition of their nonstructural systems. Despite their importance, nonstructural elements are seldom included in standard assessment procedures, and many retrofitting interventions focus exclusively on improving structural capacity. This omission represents a significant gap in current risk mitigation efforts and calls for a more integrated and performance-based approach.

Fig. 2 – (a) Plan view of the building; (b) damage to different structural components (walls and diaphragms) observed after event E3; (c) cumulative damage observed on a pier of load-bearing wall W7; (d) cumulative damage observed on a pier of load-bearing wall W9.