Numerical Modelling Of Local Seismic Response In Alluvial Valleys Filled By Heterogeneous Deposits For Seismic Microzonation Studies In Northern Latium (Italy)

After the 2016-2017 seismic sequence in Central Apennines, seismic microzonation studies were planned in the framework of the Ordinance 24 of the 12th of May 2017 (OPCM 24/2017) issued by the Italian Presidency of the Council of Ministers. Numerical simulations aiming at estimating seismic amplification factors of uniform microzones located in several municipalities of the Latium Region were carried out in order to provide quantitative elements for reconstruction. The investigated areas include alluvial valleys of variable shapes filled by heterogeneous deposits. The obtained results demonstrate that the heterogeneities of the alluvial deposits are responsible for variations in the seismic response; therefore, they cannot be neglected in estimating the local seismic response of the sites. The two case studies of Fonte del Campo and Posta were selected among the studied municipalities for illustrating the main findings.