PSI - Issue 44

Valentina Buonocunto et al. / Procedia Structural Integrity 44 (2023) 67–74 Valentina Buonocunto et al. / Structural Integrity Procedia 00 (2022) 000–000

72 6

Fig. 4a and Fig. 4b show the fragility curves obtained for our models (solid line) and those converted to the MARS model (dashed line) respectively for the buildings built between 1919-1945 and for buildings built between the 1961 1970 with three floors. In particular, it can be noted that as the number of floors and the time of construction increases, the median values of the fragility curves reduce, as does the dispersion. The conversion towards the MARS model, when the dispersion is approximately equal to that imposed in the MARS model, equal to 0.65, tends to leave the curves almost unchanged, while if the analytical curves are characterized by lower dispersions, then the conversion tends to underestimate in a noticeable way the ductility. a b

Fig. 4. Fragility curves related to different construction periods and numbers of storeys: (a) 1919-1945, 1 storey; (b) 1961-1970, 3 storeys

3. Validation of the vulnerability model

A major step of this study was the validation of the vulnerability model, which was based onto a comparison between simulated and observed damage. Specifically, the simulated and observed percentages of buildings reached each single DS were compared to each other. To that aim, the 1980 Irpinia earthquake was assumed as seismic scenario for validation. Simulated damage was computed using the analytical fragility curves and IRMA 2.0 platform, obtaining the damage map in Figure 5a. Observed isodamage curves were derived from Da.D.O. portal, as depicted in Figure 5b (Faenza et al. 2021). a b

Fig. 5. (a) Percentages of damaged buildings in IRMA platform under 1980 Irpinia earthquake; (b) Irpinia earthquake ShakeMap (PGA)