GNGTS 2019 - Atti del 38° Convegno Nazionale

GNGTS 2019 S essione 2.1 269 motion hazard is higher due to the effects of local geology. The impact of site effects on the hazard is particularly evident within the municipal areas of Albenga, Taggia (just east of Sanremo), and along the coast near Ventimiglia. For a site within the Albenga municipality, Figure 3 shows an example uniform hazard spectrum. Besides the considerations above, the previous examples clearly point out the benefit of integrating seismic microzonation and PSHA. Soil-specific hazard maps, such as those presented in this study, go beyond conventional seismic hazard maps on rock (or adjusted through the application of generic site factors), as they have the clear advantage of providing the final user with a comprehensive picture of the actual (i.e., specific) seismic hazard in a region or municipality. Future advances will concern the possibility of using frequency- dependent amplification factors, in order to obtain finer seismic hazard maps. References Barani S., De Ferrari R. and Ferretti G.; 2013: Influence of soil modeling uncertainties on site response . Earthq. Spectra, 29 , 705-732. Barani S. and Spallarossa D.; 2017: Soil amplification in probabilistic ground motion hazard analysis . Bull. Earthq. Eng., 15 , 2525-2545. Barani S., Spallarossa D. and Bazzurro P.; 2009: Disaggregation of probabilistic ground-motion hazard in Italy . Bull. Seismol. Soc. Am., 99 , 2638-2661. Barani S., Spallarossa D., Pacor F., Felicetta C., Kotha S. R., Bindi D., Cotton F. and Bazzurro P.; 2019: A non- parametric approach to site- and soil-specific probabilistic seismic hazard analysis . Proceedings of the 7th lnternational Conference on Earthquake Geotechnical Engineering, Rome, Italy. Bindi D., Massa M., Luzi L., Ameri G., Pacor F., Puglia R. and Augliera P.; 2014: Pan-European ground-motion prediction equations for the average horizontal component of PGA, PGV, and 5%-damped PSA at spectral periods up to 3.0 s using the RESORCE dataset . Bull. Earthq. Eng., 12 , 391-430. Boncio P., Pizzi A., Cavuoto G., Mancini M., Piacentini T., Miccadei E., Cavinato G.P., Piscitelli S., Giocoli A., Ferretti G., De Ferrari R., Gallipoli M.R., Mucciarelli M., Di Fiore V., Franceschini A., Pergalani F., Naso G. and Working Group MacroArea3; 2011: Geological and geophysical characterisation of the Paganica - San Gregorio area after the April 6, 2009 L’Aquila earthquake (Mw 6.3, central Italy): implications for site response . Boll. Geofis. Teor. Appl., 52 , 491-512. Compagnoni M., Pergalani F. and Boncio P.; 2011: Microzonation study in the Paganica-San Gregorio area affected by the April 6, 2009 L’Aquila earthquake (central Italy) and implications for the reconstruction . Bull. Earthq. Eng., 9 , 181-198. Faccioli E., Paolucci R. and Vanini M.; 2015: Evaluation of probabilistic site-specific seismic-hazard methods and associated uncertainties, with applications in the Po Plain, Northern Italy . Bull. Seismol. Soc. Am., 105 , 2787-2807. Felicetta C., Lanzano G., D’Amico M., Puglia R., Luzi L. and Pacor F.; 2018: Ground motion model for reference rock sites in Italy . Soil Dyn. Earthq. Eng., 110 , 276-283. Idriss I.M. and Sun J.I.; 1993: User’s manual for Shake91: a computer program for conducting equivalent linear seismic response analyses of horizontally layered soil deposit . Center for geotechnical modeling, Dept. of Civil and Environmental Engineering, University of California, Davis. Lanzo G., Silvestri F., Costanzo A., D’Onofrio A., Martelli L., Pagliaroli A., Sica S. and Simonelli A.; 2011: Site response studies and seismic microzoning in the Middle Aterno valley (L’Aquila, Central Italy) . Bull. Earthq. Eng., 9 , 1417-1442. Fig. 3 - Uniform hazard spectrum corresponding to a 475-year return period for a site within the Albenga municipality. The dashed lines indicate the uniform hazard spectra corresponding to the 16 th and 84 th percentiles.