Seismic hazard assessment at municipality scale: the Unesco cultural heritage site of San Gimignano (Italy)

In the frame of the project Rischio Sismico negli Edifici Monumentali-RiSEM (Seismic Risk in Monumental Buildings), a seismogeological reference model was developed for the historical center of the town of San Gimignano in central Italy in order to evaluate possible small-scale lateral variation of seismic hazard. To this aim, an on-purpose geological and geomorphological survey was performed along with ambient vibration measurements (both in a single station and array configurations) to characterize seismic response in the study area. Expectedseismic amplificationeffectswere quantifiedby considering asimplifiedapproach developedinItaly forseismic microzoning at the municipality scale. This study provided preliminary information supporting site-specific analyses of the local seismic response and makes it possible the identify most critical situations in which eventual seismic retrofitting interventions are more urgent to reduce seismic risk