GNGTS 2022 - Atti del 40° Convegno Nazionale

340 GNGTS 2022 Sessione 2.2 This table shows that the best correlation is between both EDP and the Housner Intensity, so it will be used as the reference for the fragility curves results. The results show a clear dynamic response difference of the buildings varying the regularity: the RF structure suffers less displacements overall than the NRF2 structure, as shown in the Fig 2 – MIDR Fragility Curves . The highest deformability of the NRF2 structure derives from the higher non-regularity and torsional effects. The threshold selection is a key factor for the right construction of the fragility curves. In this work, the MIDR thresholds are identified via pushover analysis of the buildings, although pushover analyses are not recommendable for studying buildings characterized by high levels of non-regularity, since the first vibration mode is not well defined. The implementation of the chord-rotation capacity as an Engineering Demand Parameter has the aim to implicitly consider the Collapse Prevention Limit State reached by every element of the reference structure avoiding the necessity to assess non-regular structure capacity by means of pushover analysis. Thus, the fragility curves constructed with the MCRC as EDP are more representative of the real behaviour of the buildings. These fragility curves confirm the high deformability of NRF2, but also an aggravation of the dynamic response of the structures, suggesting that the use of MCRC as EDP leads to a more cautionary reading than MIDR, as shown in Fig 3 – MCRC Fragility curves . References ASCE; 2014: Seismic Evaluation and Retrofit of Existing Buildings. American Society of Civil Engineers, Reston, VA. Barbagallo F., Bosco M., Marino E. M., Rossi P.P., 2019: On the fibre modelling of beams in RC framed buildings with rigid diaphragm . Department of Civil Engineering and Architecture, University of Catania, Catania, Italy Boore D. M, Watson-Lamprey J., Abrahamson N. A.; 2006: Orientation-Independent Measures of Ground Motion . Bulletin of the Seismological Society of America, Vol. 96 Tab. 3 - Standard deviations.