PSI - Issue 44

Stefano Bracchi et al. / Procedia Structural Integrity 44 (2023) 394–401

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Stefano Bracchi et al. / Structural Integrity Procedia 00 (2022) 000 – 000

the ultimate limit state are calculated. From the obtained distributions of acceleration and displacement capacity, values of partial safety factors of displacement capacity are calculated. The results for the considered case study show that moving from KL1 to KL2, a general reduction of uncertainties on displacement and acceleration capacity is present; the reduction is larger when good quality mortar is assumed. At KL3, the fact that the structure can have different material properties (bad, average or good) is considered. This issue influences the dispersion of the results. Hence, a lack of reduction of uncertainties at KL3 can be observed in case of bad quality masonry, whereas reduction of uncertainties is taking place when better quality masonry is assumed. Performing a larger number of in-situ tests does not lead to a noticeable reduction of uncertainties in case of weak mortar, whereas it does in case of masonry with average or good quality and with good quality mortar. This is also partially due to the formulation proposed for the Bayesian updating of values of mechanical properties, which differs from the one introduced in the Italian code (NTC18) reducing the relative weight of experimental results. The values of partial safety factors calculated appear to be lower than the ones proposed by EC8, although they obviously reflect the consideration of a single case study. Acknowledgements This work was carried out within the framework of the ReLUIS Projects 2019-21 and 2022-24 - WP10: Code contributions for existing masonry constructions, funded by the Italian Department of Civil Protection. References Binda, L., Mirabella Roberti, G., Tiraboschi, C., 1996. Problemi di misura dei parametri meccanici della muratura e dei suoi componenti. Proc eedings of the National Conference “La meccanica delle murature tra t eoria e progetto, Messina, Italy. Bracchi, S., Rota, M., Penna, A., Magenes, G., 2015. Consideration of modelling uncertainties in the seismic assessment of masonry buildings by equivalent-frame approach. Bulletin of Earthquake Engineering 13(11), 3423-3448. Bracchi, S., Rota, M., Magenes, G., Penna, A., 2016. Seismic assessment of masonry buildings accounting for limited knowledge on materials by Bayesian updating. Bulletin of Earthquake Engineering 14(8), 2273-2297. Cattari, S., Lagomarsino, S., 2013. Masonry structures, in: Developments in the field of displacement based seismic assessment, Sullivan T, Calvi GM (eds.). IUSS Press, Pavia, Italy, 151-200. Franchin, P., Pinto, P.E., Rajeev, P., 2010. Confidence factor. Journal of Earthquake Engineering 14(7), 989-1007. Franchin, P., Ragni, L., Rota, M., Zona A., 2018. Modelling uncertainties of Italian code-conforming structures for the purpose of seismic response analysis. Journal of Earthquake Engineering 22(sup2), 1964-1989. EN 1998-3, 2005. Eurocode 8: Design of structures for earthquake resistance - Part 3: Assessment and retrofitting of buildings, CEN, Brussels, Belgium. EN1998-3, 2021. Eurocode 8: Design of structures for earthquake resistance – Part 3: Assessment and retrofitting of buildings and bridges. Final Document EN1998-3 NEN SC8 PT3. Lagomarsino, S., Penna, A., Galasco, A., Cattari, S., 2013. TREMURI program: an equivalent frame model for the nonlinear seismic analysis of masonry buildings. Engineering Structures 56, 1787-1799. NTC18, 2018. Decreto ministeriale 20/2/2018: norme tecniche delle costruzioni. Ministero delle Infrastrutture e dei trasporti, S.O. No. 8 alla G.U. No. 42 del 20/2/2018, Ministero delle Infrastrutture e dei Trasporti, Rome, Italy. Morandi, P., Albanesi, L., Graziotti, F., Li Piani, T., Penna, A., Magenes, G., 2018. Development of a dataset on the in-plane experimental response of URM piers with bricks and blocks. Construction and Building Materials 190, 593-611. Tondelli, M., Rota, M., Penna, A., Magenes G., 2012. Evaluation of uncertainties in the seismic assessment of existing masonry buildings. Journal of Earthquake Engineering 16(S1), 36-64. Turnšek, V., Sheppard, P., 1980. The shear and flexural resistance of masonry walls, Proceedings of the International Research Conference on Earthquake Engineering, Skopje, Macedonia. Rota, M., Penna, A., Magenes, G., 2014. A framework for the seismic assessment of existing masonry buildings accounting for different sources of uncertainty. Earthquake Engineering and Structural Dynamics 43(7), 1045-1066.