# 2-D Seismic Response Analysis of a Slope in the Tyrrhenian Area (Italy)
## 2 Site Characterization
### Investigation Program and Geotechnical Soil Properties
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \multirow{2}{*}{**Site**} & **D** & **\(\gamma\)** & **\(W_{\text{a}}\)** & **\(W_{\text{L}}\)** & **\(W_{\text{P}}\)** & **PI** & **CI** & **AI** \\  & **[m]** & **[kN/m3]** & **[\%]** & **[\%]** & **[\%]** & **[\%]** & **[\%]** & **[\%]** & **[\%]** \\ \hline BH2 CI1 & 2.50–3.00 & 19.81 & 12.54 & 34.17 & 11.98 & 22.19 & 0.97 & 1.07 \\ BH3 CI1 & 2.50–3.00 & 19.71 & 26.21 & 31.78 & 22.71 & 9.07 & 1.58 & 0.34 \\ BH3 CI2 & 6.00–6.40 & 19.61 & 22.65 & 37.63 & 19.74 & 17.89 & 0.97 & 0.44 \\ BH4 CI1 & 7.30–7.60 & 18.24 & 15.78 & 53.27 & 20.20 & 33.07 & 0.99 & 0.64 \\ BH4 CI2 & 10.70–11.00 & 19.22 & 24.45 & 22.58 & 13.42 & 9.16 & 1.29 & 0.52 \\ BH5 CI1 & 12.00–12.45 & 19.12 & 26.35 & 48.56 & 20.06 & 28.50 & 0.96 & 0.48 \\ BH102-CM1 & 4.20–450 & 19.71 & 14.12 & 38.00 & 17.00 & 21.00 & 1.14 & 0.87 \\ BH2 CI1 & 2.50–3.00 & 19.81 & 12.54 & 34.17 & 11.98 & 22.19 & 0.97 & 1.07 \\ BH3 CI1 & 2.50–3.00 & 19.71 & 26.21 & 31.78 & 22.71 & 9.07 & 1.58 & 0.34 \\ BH3 CI2 & 6.00–6.40 & 19.61 & 22.65 & 37.63 & 19.74 & 17.89 & 0.97 & 0.44 \\ BH4 CI1 & 7.30–7.60 & 18.24 & 15.78 & 53.27 & 20.20 & 33.07 & 0.99 & 0.64 \\ BH4 CI2 & 10.70–11.00 & 19.22 & 24.45 & 22.58 & 13.42 & 9.16 & 1.29 & 0.52 \\ \hline \end{tabular} where: D = Depth, \(\gamma\) = Total Unit Weight, \(W_{\text{n}}\) = Water Content, \(W_{\text{L}}\) = Liquid Limit, \(W_{\text{P}}\) = Plastic Limit, PI = Plasticity Index,  
CI = Consistence Index and AI = Activity Index.  
\end{table} 
Table 2: Mechanical characteristics for Caronia area. Figure 5: Soil profiles of S105 and S3 boreholes. The value (Figure 6) of the natural moisture content \(\rm w_{n}\) prevalently ranged between 11-26%, while characteristic values for e (void ratio) ranged between 0.35 and 0.74 for the Caronia test site. Regarding strength parameters of the deposits mainly (Table 3) encountered in this area, \(\rm c^{\prime}\) from DST ranged between 2.41 kPa and 51.8 kPa while \(\rm\varphi^{\prime}\) from DST ranged between 15.8\({}^{\circ}\) and 31.6\({}^{\circ}\). It was also possible to evaluate the small strain shear modulus in the Caronia area by means of the following seismic tests based on Down Hole (DH). In Figure 7, the shear and compression wave velocities are shown against depth. The shear \(\rm V_{s}\) and compression \(\rm V_{p}\) wave velocities gradually increased with depth. At the depth of about 25-30 m, there was a rapid increase in velocities due to the presence of fractured argillite. In Figure 8, the dynamic Poisson ratio (\(\rm v\)) variation with depth, obtained from the Down-Hole (DH) test, is plotted to show site characteristics. It is shown that the values oscillate around 0.03-0.48 for DH. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Site** & **D** & **e** & **n** & **Sr** & **c\({}^{\prime}\)** & **\(\rm\varphi^{\prime}\)** \\  & **[m]** & **e** & **n** & **[\%]** & **[kPa]** & **[\({}^{\circ}\)]** \\ \hline BH2 CI1 & 2.50–3.00 & 0.51 & 0.34 & 66.58 & 4.88 & 31.6 \\ BH3 CI1 & 2.50–3.00 & 0.66 & 0.40 & 69.89 & 5.86 & 27.6 \\ BH3 CI2 & 6.00–6.40 & 0.66 & 0.40 & 81.96 & 6.93 & 23.4 \\ BH44 CI1 & 7.30–7.60 & 0.57 & 0.36 & 95.58 & 19.95 & 28.1 \\ BH4 CI2 & 10.70–11.00 & 0.43 & 0.30 & 67.06 & 21.73 & 15.8 \\ BH5 CI1 & 12.00–12.45 & 0.74 & 0.43 & 78.96 & 2.41 & 16.0 \\ BH102-CM1 & 4.20–450 & 0.52 & 0.34 & 73.12 & 33.20 & 21 \\ BH2 CII & 2.50–3.00 & 0.44 & 0.30 & 67.02 & 20.30 & 22 \\ BH3 CI1 & 2.50–3.00 & 0.49 & 0.33 & 78.88 & 36.50 & 30 \\ BH3 CI2 & 6.00–6.40 & 0.44 & 0.31 & 85.07 & 51.80 & 22 \\ BH4 CI1 & 7.30–7.60 & 0.39 & 0.28 & 73.30 & 34.00 & 20 \\ BH4 CI2 & 10.70–11.00 & 0.35 & 0.26 & 85.63 & 23.20 & 21 \\ \hline \hline \end{tabular}  
* where: D = Depth, e = Void Ratio, n = Porosity, Sr = Degree of Saturation, \(\rm c^{\prime}\) = Cohesion and \(\rm\varphi^{\prime}\) = Effective friction angle from Direct Shear Test (DST).  
\end{table} 
Table 3: Mechanical characteristics for Caronia area.