PSI - Issue 44

Maria Zucconi et al. / Procedia Structural Integrity 44 (2023) 315–322 Maria Zucconi et al. / Structural Integrity Procedia 00 (2022) 000–000

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in [26]. Each record pair was applied twice to the structure by rotating 90°. Therefore, the largest spectral acceleration was applied first in the X direction and then in the Y direction.

Fig. 2 Finite element model detail of beam-column joint structural sub-system and non-linear behavior of adopted plastic hinges.

4. Ground-motion intensities and structural results In order to perform a time-based loss assessment analysis [3], different seismic scenarios must be investigated. In this work, ten different seismic scenarios, corresponding to ten different seismic intensity levels were considered and analyzed. So, ten uniform hazard spectra (UHS) have been calculated for the site of the building, by considering the proper soil class. The UHS have been obtained with reference to eight different exceedance probabilities equal to 2%, 5%, 7%, 10%, 20%, 30%, 50%, and 81% for a 50 years reference period. The 30 ground motion pairs have been scaled to match, as close as possible, their average (geometric mean) elastic spectrumwith the corresponding reference UHS of the site of the building. For each one of the eight seismic intensities, the time history analyses performed in OpenSEES provided the seismic response of the structure. Then, the main outcomes of the structural analyses have been adopted in the seismic loss analysis described in the following section. As an example Figure 3 shows the median values of the PFA for the exceedance probabilities of 63% and 10% for a 50 years reference period. They are showed for both the two different seismic scenarios considering the largest spectral acceleration applied first in the X direction and then in the Y direction. On the other hand, Figure 4 shows the median values of the peak interstorey drift ratio (IDR) for the various storeys for the two seismic scenarios, and obtained for the seismic intensity corresponding to exceedance probabilities of 63% and 10% in 50 years. For the two seismic scenarios, the results are substantially of the same order of magnitude along the building elevation, with values slightly higher for the building when the largest spectral acceleration is applied in Y direction.