GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 2.2 327 About the boundary conditions, vertical displacements were permitted to the vertical boundaries of the soil deposit, and in addition, the nodes of the soil vertical boundaries have been linked by “constraint equations” that have imposed the same horizontal translation at the same depth (Abate et al., 2016). For all the nodes of the base of the mesh only horizontal displacements were permitted. In order to model probable uplifting and/or sliding phenomena, special contact surfaces have been modelled between foundations and soil, considering a friction equal to 2/3 φ. Tab. 3 - Final G/G0 and D values determined by the linear equivalent approach for every input signal. Inputs Layer 0-14 14-24 24-30 1693-1 G/G0 0.510 0.979 0.763 D (%) 9.338 2.154 4.368 1693-2 G/G0 0.498 0.977 0.749 D (%) 9.632 2.184 4.599 1693-3 G/G0 0.511 0.978 0.751 D (%) 9.323 2.161 4.573 1818-1 G/G0 0.583 0.990 0.841 D (%) 7.662 1.833 3.132 1818-2 G/G0 0.581 0.992 0.866 D (%) 7.713 1.714 2.748 1818-3 G/G0 0.566 0.991 0.851 D (%) 8.017 1.787 2.974 1990 G/G0 0.567 0.990 0.841 D (%) 8.002 1.817 3.141 Fig. 2 - a) Frequency ratios between input and SSI (EC8), b) frequency ratios between input and SSI (non-linear iterative approach); c) amplification ratios.