GNGTS 2017 - 36° Convegno Nazionale

382 GNGTS 2017 S essione 2.2 Down-Hole and MASW) and passive (HVRS) geophysical measurements aimed at the seismic characterisation of the dynamic behaviour of the different litho-types outcropping in the area. The peculiar features highlighted by the engineering-geological investigations consist in: - �� local overlapping and/or lateral contacts between different generations of gravel deposits belonging to Quaternary alluvial fans, eluvio-colluvial sediments and heterogeneous coarse-grained talus slope deposits; - �� intensely jointed rock masses in correspondence of fault traces and rock mass creeping slopes; - �� debris and weathered soils widely covering the outcropping bedrock. All these features have been taken into account for the MOPS delineation (according to ICMS, 2008 guidelines) as well as for designing 1D-Log and 2D-sections to be used in 1D and 2D numerical modelling of local seismic response, due to stratigraphic and/or topographic effects. Specific conceptual modelling solutions have been adopted to incorporate the peculiar features in the estimation of local seismic response: - �� 2D models have been assumed to estimate the local seismic response along the Tronto River valley-floor (i.e. at Grisciano and Fonte del Campo towns). The possible effects in correspondence of the outcrop of cover deposits (characterized by different grain-size, lateral heterogeneity, and thickness) has been taken into account, reproducing the variety of contacts among them through a non-conventional resonant valley system; - �� 1D models have been assumed for analysing the local seismic response of rock mass creeping slopes (Grisciano, Tino and S. Giovanni towns) which are not regarded as unstable zones (i.e. prone to landslide processes) and where intensely jointed rock masses overlay the seismic bedrock; - �� 1D models have been applied to reproduce the different types of cover deposits due to fluvial and gravitational processes and bedrock weathering, which locally unconformably overlay the seismic bedrock. Several unstable areas have been also inventoried by an integration of previously available databases (IFFI and PAI) with the newly inventoried landslides occurred after the earthquakes on August-October 2016, as collected in the CEDIT database (http://www.ceri.uniroma1.it/ index_cedit.html). Numerical modelling has been performed under 1D and 2D conditions, these last ones by FDM and FEM codes. The obtained results have been represented inMS3maps, through areaswhere a homogeneous response can be assumed. The main outcomes will be transferred to the stakeholders for an accurate management of urban areas and for planning future reconstruction. References ICMS; 2008: Indirizzi e criteri per la microzonazione sismica. Conferenza delle Regioni e delle Province autonome - Dipartimento della Protezione Civile, Roma, Italy, 3 vol. and Dvd.