Seismic Hazard Assessment at Municipality Scale: 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. Expected seismic amplification effects were quantified by considering a simplified approach developed in Italy for seismic 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.