GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 Figure 1: Geological map of the area of interest with location of the damaged building and main geotechnical and geophysical tests Geological and geophysical model The lithostratigraphic sequence was defined by means of geophysical surveys, refraction seismic line with 2D tomographic processing, Re.Mi./MASW tests, ambient noise measurements (HVSR), and previous geotechnical tests: cone penetration tests (CPT), super heavy dynamic penetration tests (DPSH), and Down-Hole test (Beretti, 2013). The site is characterised by a first unit consisting of clayey-silty and siltysandy alternations, with intercalation of silty-clayey lenses and fine gravel, characterised by Vp<2 km/s and Vs<300÷350 m/s, with strong variability in thickness, which reaches 20 m in the centre of the valley. The marly substratum is characterised by an altered band, with Vp between 2 and 2.8 km/s and Vs about 400÷450 m/s, which reaches a thickness of 6÷8 m in the centre of the valley. The unaltered substratum is characterised by values of Vp>3 km/s and Vs>500 m/s, that gradually increase with depth. Vs exceeds 800 m/s at a depth of about 30 to 40 m on the valley sides and over 70 m in the central zone.