PSI - Issue 44

Brandonisio Giuseppe et al. / Procedia Structural Integrity 44 (2023) 1292–1299 Giuseppe Brandonisio et al. / Structural Integrity Procedia 00 (2022) 000–000

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Fig. 6. Comparison between dynamic characteristics of the four models- 2 nd vibration mode.

Fig. 7. Comparison between dynamic characteristics of the four models- 3 rd vibration mode.

Fig. 8. Comparison between the cumulative mass percentage in x-direction (left) and y-direction(right). Fig. 9 relates to the spectral acceleration associated to the first vibration mode of model 1 and model 4 From their comparison, the effectiveness of BIS in terms of seismic demand is clear. The spectral acceleration is reduced from S d (T 1, model#1 )=0.2g of the current state (valued on the design spectrum, assuming q=1.5) to Sd( 1, model#4 )=0.05g (value on the elastic spectrum), with a reduction of the spectral acceleration equal to 75%. Fig. 10 and Fig. 11 display result comparison in terms of seismic shear force distribution at the base of model 3 and model 4. In particular, Fig. 10 refers to model 3 (all buildings connected at each floor level + strengthening shear walls), applying seismic action in x and y-directions respectively. Fig.11 refers to model 4 (final isolated solution). From comparison we can draw some considerations that highlight the effectiveness of the hybrid solution, as valuable strategy for seismic hazard mitigation.