Reconstructing seismic ground motion at reference site conditions: the case of accelerometric records of the Italian National Accelerometric Network (RAN)

To compare the outcomes of seismic hazard models with accelerometric records, the seismic ground motion at the reference soil conditions considered by the hazard estimates must be reconstructed. Here we illustrate the procedure proposed and operated to this purpose in the frame of the Italian DPC-INGV-S2 project. This includes two phases: the geological/geophysical characterization of the sites to be analysed and a numerical deconvolution analysis, carried on by considering specific records representative of the maximum ground motion observed at the relevant accelerometric sites. Particular attention was addressed to manage the uncertainty associated to this kind of analysis. Results are then compared with those obtained by simply applying the “correction” coefficients provided by the Italian National Seismic Code to account for site conditions.