Geophysical investigations and engineering geological modelling for the local seismic response study of the Rieti historical centre (Central Italy)

Italy is characterised by a wide cultural heritage distributed in numerous historical centres of cities and villages located in areas having high seismicity, as evidenced during the 2016-2017 Central Italy seismic sequence that caused severe damages on buildings, hundreds of casualties and economic losses of the artistic and cultural heritage. In a seismic risk management framework, the SIS-DAT project will develop a GIS software platform producing maps of damage scenarios in historical centres with relation to selected levels of seismic hazard and implementation of seismic improvement interventions. The historical centre of Rieti (Central Italy) was selected as test site for the SIS-DAT project. An engineering geological model was reconstructed for the site using data available from previously performed surveys and newly performed passive seismic surveys consisting of single-station and array seismic ambient noise measurements. In addition, the installation of a temporary seismic monitoring network was carried out. The analysis of the seismic measurements allowed to identify the resonance frequency of the different zones composing the Rieti historical centre as well as to calibrate and validate the engineering geological model of the site. Based on such model, a 2D numerical modelling was planned to analyse the local seismic response of the site.