GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 Seismic hazard-based liquefaction triggering map for Italy S. Barani, G. Ferretti, Davide Scafidi Dipartimento di Scienze della Terra dell’Ambiente e della Vita, Università degli Studi di Genova, Genova, Italy In the present study, we analyze ground-motion hazard maps (MPS Working group, 2004; Stucchi et al., 2011) and hazard disaggregation (Barani et al., 2009) to define areas in Italy where liquefaction triggering due to seismic activity cannot be excluded, and geotechnical analyses aimed at verifying the liquefaction potential discounted. To this end, we refer to the triggering criterion proposed by the Italian Guidelines for Seismic Microzonation (SM Working Group, 2015), according to which liquefaction is expected to be triggered if the following condition is met: the expected seismic events must be characterized by magnitude values Mw ≥ 5 and must produce a surface peak ground acceleration amax ≥ 0.1g. If the condition above is not verified, at least in principle, we can assume that the area under study is not susceptible to liquefaction. The final goal of our study is the definition of a screening map for all of Italy, called MILQ (Mappa del potenziale d’Innesco della LiQuefazione), that classifies sites in terms of liquefaction triggering potential according to their seismic hazard level. The map, whose reliability is examined by analyzing the geographic distribution of past liquefaction phenomena reported in the Italian Catalogue of Earthquake-Induced Ground Failures – CEDIT (Caprari et al., 2018), and the associated data are freely accessible at the following web address: www.distav.unige.it/rsni/milq.php.