PSI - Issue 78

Fabio Mazza et al. / Procedia Structural Integrity 78 (2026) 33–40

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masonry infills (MIs) placed along the perimeter of the building plan. In all cases, greater values of vertical structural acceleration are recorded for the BIH structure with respect to the BIHV one, proving the effectiveness of the vertical base-isolation. A notable difference between end and mid-span sections of beams is also highlighted along the building height for beams characterized by the highest aspect ratio of MIs. NSEs thresholds for rigid and flexible elements lying on the floors are generally exceeded for both BF and IF structures, especially when horizontal base-isolation is considered, while these thresholds are generally conservative when horizontal and vertical base-isolation is assumed. Moreover, similar thresholds are usually satisfied for rigid and flexible NSEs hanging from MIs. Spectrograms resulting from the wavelet analysis of time histories of the vertical acceleration at the top floor highlight a significant increase of the maximum WTC value of the BIH structures in the infilled configuration. Finally, a significant reduction of WTC shifting backward in time happens for the BIHV structure characterized by an elongation of the fundamental vibration period in the vertical direction. Acknowledgements The studies presented here were carried out as part of the work envisaged by the Agreement between the Italian Department of Civil Protection (DPC) and the ReLUIS Consortium (Convenzione D.P.C.-Re.L.U.I.S. 2024 – 2026, WP15, Devices and systems of Isolation and Dissipation). The contents of this paper represent the authors’ ideas and do not necessarily correspond to the official opinion and policies of the DPC. References Di Sarno, L., Elnashai, A. S., Manfredi, G., 2011. Assessment of RC columns subjected to horizontal and vertical ground motions recorder during the 2009 L’Aquila (Italy) earthquake. Engineering Structures, 33:1514 -1535. DM96 1996. Norme tecniche per le costruzioni in zone sismiche e relative istruzioni, D.M. 16-01-1996 and C.M. 10-04-1997, Italian Ministry of Public Works, Rome, Italy (in Italian). EN15129. 2009. Antiseismic Devices. Comité Européen de Normalisation (CEN), Brussels, Belgium. Eurocode 8. 2005. Design of structures for earthquake resistance – part 2: bridges. Comité Européen de Normalisation (CEN), Brussels, Belgium. Filiatrault, A., Sullivan, T., 2014. Performance-based seismic design of nonstructural building components: The next frontier of earthquake engineering. Earthquake Engineering and Engineering Vibrations, 13:17-46. Mazza, F., Braile, A., 2024. Vertical isolation ratio of base-isolated RC structures subjected to near-fault earthquakes. Procs. of the 18th World Conference on Earthquake Engineering, 30th June – 5th July, Milan, Italy. Mazza, F., Braile. A., Labernarda, R., 2024a. Wavelet analysis for the vertical isolation ratio of RC hospital structures subjected to near-fault earthquakes. In: ECCOMAS 2024. doi: 10.23967/eccomas.2024.132 Mazza, F., Donnici, A., Labernarda, R., 2024b. Structural and non-structural numerical blind prediction of shaking table experimental tests on fixed-base and base-isolated hospitals. Earthquake Engineering and Structural Dynamics, 53(10):2961-2987. Mazza, F., Labernarda, R. 2021. Internal pounding between structural parts of seismically isolated buildings. Journal of Earthquake Engineering, 26(10): 5175-5203. doi: 10.1080/13632469.2020.1866122 Mazza, F., 2016. Effects of near-fault vertical earthquakes on the nonlinear incremental response of r.c. base-isolated structures exposed to fire. Bulletin of Earthquake Engineering, 14(2): 433-454. Mazza, F., 2021. Base-isolation of a hospital pavilion against in-plane-out-of-plane seismic collapse of masonry infills. Engineering Structures, 228:111504. MATLAB, 2018. MATrix LABoratory (9.7.0.1190202, R2019b). Natick, Massachusetts. The MathWorks Inc. Merino, R. J., Perrone, D., Nascimbene, R., Filiatrault, A., 2023. Performance-based seismic classification of acceleration-sensitive non-structural elements. Earthquake Engineering and Structural Dynamics, 52:4222-4224. NTC2018. 2018. Norme tecniche per le costruzioni e relative istruzioni, D.M. 17-01-2018 and C.M. 11-02-2019. Ministero delle Infrastrutture e dei Trasporti, Rome, Italy. Pacific Earthquake Engineering Research Center database, PEER, 2004. https://ngawest2.berkeley.edu/ Pourmasoud, M. M., Lim, J. B., Hajirasouliha, P. I., McCrum, D., 2020. Multi-directional base isolation system for coupled horizontal and vertical seismic excitations. Journal of Earthquake Engineering, 26(3): 1-26. Shahi, S. K., Baker J. W., 2014. An Efficient Algorithm to Identify Strong-Velocity Pulses in Multicomponent Ground Motions. Bulletin of the Seismological Society of America, Vol. 104, No. 5, pp. 2456 – 2466, October 2014, doi: 10.1785/0120130191