GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 Non-linear behaviour of the ground For the non-linear behaviour of the ground, degradation curves from literature and results from cyclic simple shear test and two resonant column tests were used (samples from -3÷-4 m pc and -12.5÷-13 m pc, Beretti, 2013). To eliminate possible alterations due to data dispersion, the Yokota et al. (1981) model was used to represent the variation of G and D with the shear deformation amplitude γ (expressed in %). The Vs profiles were discretised, in values and depths, down to the seismic bedrock (Vs=800 m/s), based on the results of the on-site geophysical tests. Surface seismic motion amplification The 2D analysis shows that the amplification of the seismic motion develops mainly in the middle of the valley, on the footwal, where the thickness of the cover is greater (Fig. 3). To the east, on the hangingwall, the thickness of the cover is less and gradually decreases towards the edge of the valley. In this area, the amplification values are lower (Fig. 3). Figure 3: Distribution of amplification factors along the cross-section (TR=475 y)