PSI - Issue 78

Emanuele Maiorana et al. / Procedia Structural Integrity 78 (2026) 57–64

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additional intrinsic vulnerabilities, often stemming from original construction deficiencies. These investigations uncovered problematic construction details, including non-structural wall partitions masquerading as load-bearing elements. The survey systematically documented existing damage and stabilized conditions, with particular focus on crack patterns, potential failure mechanisms, and localized vulnerabilities in both structural and non-structural elements. Roof system inspection confirmed its generally non-thrusting character, attributable to thrust-restraining devices (chains), with only minor exceptions. Of particular significance was the observed cracking at the first-floor keystone adjacent to classrooms. Subsequent investigation revealed a roofing support strut directly transferring loads to this keystone (Figs. 4-5), explaining the observed distress. This load path discovery underscores the importance of understanding secondary structural interactions in vulnerability assessments.

Fig. 4. Strut above the first arch key.

Fig. 5. Slit at the first arch key.

A similar condition was observed in a corresponding arch at the opposite end of the corridor (Fig. 6). In this instance, the cracking pattern observed in the arch keystone appears to result from load transfer through a roof-level crosspiece that interrupts the structural section (Fig. 7).

Fig. 6. Slit at the second arch key.

Fig. 7. Crosspiece above the second arch key.

Limited access to the narrow basement areas restricted verification of foundation composition and geometry to only a few observable details. Based on evidence from targeted excavations, the foundation system is presumed to consist of continuous dry-laid footings following the main perimeter walls of each building section. These are surmounted by longitudinal and transverse brick arches and vaults, which appear to provide additional stiffness to the overall structural system.