GNGTS 2013 - Atti del 32° Convegno Nazionale

The down-hole measurements and the V S30 allows us to define the study area, in accordance with the OPCM 3274/2003, D.M. 14/01/2008 “Categories of ground” and with the elasto- dynamical parameters, as a B-type soil. Acknowledgement. This work was funded by a financial support of the Catania University (PRA n. 20104001082, Scientific Responsible: Imposa S.). References Abu-Zeid N., Vuillermin F. 1996. Analiysis of possible relationships between seismic properties and some of Rock mass geomechanic properties of the outcropping carbonate rock masses in Wadi El-kaffrien dam site (Jordan). Proceedings of the Application of Geophysics to Engineering and Enviromental Problems, pp. 605-616. Boatwright J., Porcella R., Fumal T., Liu Hsi-Ping 1987, Direct estimates of shear wave amplification from a borehole near Coalinga, California, Earthquake Notes, v. 57, 8 p. Carbone S., Di Geronimo I., Grasso M., Iozzia S., Lentini F. 1982. I terrazzi marini quaternari dell’area iblea. Contr. alla realizzazione della Carta Neotettonica d’Italia C.N.R., P.F. Geodinamica, N° 506, (Giannini Ed.) Napoli. Cosma C., Heikkinen P., Keskinen J., Enescu N. 2001. VSP in crystalline rocks from down-hole velocity pro.ling to 3D fracture mapping. International Journal of Rock Mechanics & Mining Sciences, 38, 843-850. Ghisetti F., Vezzani L. 1980. The structural features of the Hyblean Plateau and of the Mount Judica area (South-Eastern Sicily): a microtectonic contribution to the deformation history of the Calabrian Arc. Bull. Soc. Geol. It., 99, 57-102. Grasso M., Pedley H.M., Maniscalco R., Ruggieri R. 2000. Geological context and explanatory notes of the “Geological Map of central-southern sector of the Hyblean Plateau.” Mem. Soc. Geol. It., 55, 45-52. Imposa S., Corrao M., Barone F., Coco G., Occhipinti R., Mozzicato P. 2010. Geostructural and geognostic survey for a stability analysis of the calcareous cliff of Ispica (Hyblean plateau, southeastern Sicily). Bulletin of Engineering Geology and the Environment, 69, 2, 247-256, ISSN: 1435-9529, doi: 10.1007/s10064-009-0257-3. Sambuelli L., Godio A., Socco L.V., Dall’Ara A., Vaira G., Deidda G. 2004. Metodi geofisici per la caratterizzazione degli ammassi rocciosi, In: La caratterizzazione degli ammassi rocciosi nella progettazione geotecnica, PATRON (ITA), MIR 2004, Torino 24-25 novembre 2004, pp. 47-90, Vol. 1, ISBN: 88-555-2782-7. Pullammanappallil S. K., Louie J. N. 1994. “A Generalized Simulated- Annealing Optimization for Inversion of First- Arrival Times”. Bulletin of the Seismological Society of America, Vol. 84, No. 5, pp. 1397-1409. O.P.C.M. 3274/2003. Ordinanza del Consiglio dei Ministri 3274 del 20/3/2003,“Primi elementi in materia di criteri generali per la classificazione sismica del territorio nazionale e normative tecniche per la costruzione in zona sismica”, pubblicata nel Supplemento n. 72 alla Gazzetta Ufficiale n. 105 del 08/05/2003. HIGH RESOLUTION SEISMIC REFLECTION/REFRACTION PROFILING ACROSS A LARGE DEBRIS FLOW FAN (VINSCHGAU/VENOSTA VALLEY, ITALIAN ALPS) S. Maraio 1 , P.P.G. Bruno 2 , V. Picotti 1 1 Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna, Italy 2 INGV, Istituto Nazionale di Geofisica e Vulcanologia, Napoli, Italy Introduction and approach. Fan-shaped deposits are common in formerly glaciated mountains, especially where steep tributary valleys join broad troughs; this being a classic locus where high volumes of mobilized sediment suffer a sudden loss of transport power. The term ‘alluvial fan’ generally includes both fluvial and debris-flow-dominated deposits. A group of exceptionally large alluvial fans occurs in Val Venosta, a major glacial trough in the east-central Alps, Italy. The Val Venosta group is the largest group in the Alps; concentrated glacial erosion in conducive geology among the probable cause explaining anomalous fans number and size. In this work, our attention is focused on the “Allitz/Laas” fan; it is one of the largest symmetrical fans in the Alps: it deflects the Adige River to the opposite slope foot and dominates Val Venosta as an extraordinary half-barrier. We have acquired and processed an 4 km long high-resolution seismic reflection profile across the Allitz/Laas fan, crossing the residential area of the village of Laas. The target of this work is the study of the shallow portion (about 500 m deep) of this alluvial fan. We had two principal investigation aims. First aim is the imaging of the bedrock, in order to define its depth and consequently to estimate the thickness of sediment accumulation, as well as to analyze the morphology of the bedrock and the valley engraving. Second investigation aim is the analysis of the sediment’s stratigraphy, in order to retrace the formation history of the alluvial fan. This information will provide us with important knowledge about the debated genesis of Adige Valley. Seismic stratigraphic 51 GNGTS 2013 S essione 3.1