PSI - Issue 44

4

Angela Chiecchio/ Structural Integrity Procedia 00 (2022) 000–000

Angela Chiecchio et al. / Procedia Structural Integrity 44 (2023) 11–18

14

T = 0.2s

M* = 4.8 Rjb* = 5 eps* = 1.5

4.8

5

T = 1s

M* = 6.8 Rjb* = 15 eps* = 0.5

6.8

15

Fig. 1 L’Aquila. (Left): UH spectra from MPS04 work, for 475 years of return period, compared with the Ambraseys et al. (1996) spectra (AMB96) obtained using the modal disaggregation scenarios from Barani et al. (2009), which are highlighted on the right. (Right): Contribution to hazard plots (i.e., joint probability mass function PMF) for 0.2s and 1s, for 475yr of return period and for different epsilon ( ε ) bins (adapted from Barani et al., 2009).

3. Application and results For the purpose of illustration, three Italian sites (Firenze, Catania and L’Aquila) were selected to show an example of the application of the BMSE. The UH spectra for 475 years of return period calculated for the official Italian Seismic Hazard (SH) Map in the MPS04 project (MPS Working group, 2004) were taken as target spectra for each site. The ZS9 model by Meletti et al. (2008) and the GMM of Ambraseys et al. (1996), used in such work was taken as reference for the calculations. Suitable conversion laws from epicentral R epi to Joyner and Boore R jb distances (from Sgobba et al., 2021) and from M w to M s magnitudes (MPS Working group, 2004) were adopted in the GMM calculations. Moreover, for all the results herein shown for 475 years, a fixed value of ε =0 was chosen, in order to identify the earthquake scenario, the median ground motion of which best approaches the target UHS.