VSP processed down-hole data within local seismic response assessment

Local effects evaluation may be solved using different methodological ways. VEL Project of Tuscany district approach, foresees the evaluation of the surface effects in a specified zone of a "forecasted" earthquake, through geological, geomorphologic, geotechnical, geophysical and numerical modelling. The knowledge of bedrock depth and geometry is a fundamental issue in such a multidisciplinary integrated approach. Down-hole tests carried out in not sufficiently deep borehole to reach bedrock, have been processed as VSP (Vertical Seismic Profiling) method, allowing the knowledge of bedrock depth. This has been obtained developing a processing aimed to the study of reflected signals that provided important information on discontinuities occurring below the borehole bottom. Results obtained by VSP processing from conventional SH waves down-hole data, have been calibrated by comparison with an high-resolution shear wave reflection line carried out in the same site. This comparison provided new cognitive elements and work prospects.