Integrated subsoil model for seismic microzonation in the Central Archaeological Area of Rome (Italy)

An integrated subsoil model for seismic microzonation in the Central Archaeological Area of Rome is presented in this study. This model was created in the framework of a research project aimed at evaluating the geohazard level affecting Palatine hill, Roman Forum and Coliseum. A multidisciplinary survey was carried out mainly in 2010 including continuous-coring boreholes, in situ and laboratory geotechnical tests, MASW, Cross and Down-Hole tests, ambient noise measurements, Electrical Resistivity Tomographies, Ground Penetrating Radar surveys. The surveying methodologies adopted in the surveying campaign are also presented here. A three step procedure adopted for creating the integrated subsoil model of Palatine hill and surrounding areas is described in detail. This procedure first involves the construction of a geological model starting mainly from boreholes' data interpretation and correlation. Geological formations are here interpreted in terms of lithofacies following their sedimentological features and then characteri-zed by means of their main physical properties (i.e. grain size distribution, void ratio, unit weight, plasticity index) to define a scheme of lithotypes. The lithotypes represent the "framework" to be characteri-zed in terms of dynamical properties to produce the final inputs for 1D and 2D numerical modeling of ground motion amplification effects aimed at the construction of seismic microzonation maps.