PSI - Issue 44

Giorgia Cianchino et al. / Procedia Structural Integrity 44 (2023) 219–226 Giorgia Cianchino et al. / Structural Integrity Procedia 00 (2022) 000–000

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wall thickness (<60 cm) featured by brick masonry buildings which in turn results into a lower mass of the overturning macro-element and, consequently, into a lower stabilizing moment. • The building featuring the most ductile behavior is archetype #22, an irregular masonry building of 2 stories. In fact, for the different damage levels the curves are further apart. Generally, old masonry buildings lacking connections between walls are expected to be very vulnerable and brittle, given the high probability to undergo out-of-plane mechanisms. This implies that severe damage levels are already reached for PGA values slightly higher than those yielding moderate damage. Yet, in the case of archetype #22, the high mass of the macro-element, with a thickness of about 80 cm and low height, causes that severe damage (from D3 to D5) is achieved for PGA values sensibly different from each other. • The results of the fragility curves are pivotal to determine mitigation strategies for reducing the seismic vulnerability of historical centers.

Irregular masonry - Without courses

Brick masonry

2 Stories 3 Stories 4 Stories

Figure 4. Analytical fragility curves of the six buildings analyzed. The points represent the cumulative frequencies of DPM that are then intercepted by the lognormal curve (continuous line).