GNGTS 2021 - Atti del 39° Convegno Nazionale

GNGTS 2021 S essione 2.2 342 predicted by the GMM of Lanzano et al. (2019) is always between the mean value ± standard deviation. The coefficient of variation ranges between 9% and 17%, showing a lower variability respect to the natural accelerograms. However, we did not include further variability, e.g., considering the standard deviations of the GMM, in order to avoid an excessive dispersion of the results and to have a good match with the target response spectrum even for a small number of simulations. We considered a variability between 0 and 1 s of the values foreseen by the empirical predictive equations only for the strong-motion duration that is not affected by the phase variability. Fig. 3 compares the averaged response spectra resulting from twenty simulations with the spectra predicted by the GMM of Lanzano et al. (2019) for different magnitudes, distances, and site conditions. The fit is satisfactory for all the considered cases. Fig. 2 - Accelerogram recorded at AQP station during the L’Aquila earthquake (Mw=5.4, R JB = 8.9 km, normal fault, V S30 =836 m/s) of April 2009, compared with a simulation (SIM7) in terms of acceleration, velocity, displacement and Fourier spectrum.