# Analysis of Multilayered Ground Amplification Characteristics by Scaled-Down Model Tests
## 2 Materials and Methods  
### Soil Properties and Experimental Equipment  
The soil used in the model test was collected from a cut slope at a construction site in Ulju-gun, Ulsan Metropolitan City to represent the domestic reclamation and weathered soil slopes. To analyze the geotechnical index properties of the sample, the specific gravity test, the particle size analysis test and the standard proctor test were performed. According to the analysis of the grain size distribution curve, the finer content of the sample was 10.8%. The specific gravity of the soil was 2.69 and the optimum moisture content of the soil was 12.5%. The maximum dry weight was 18.29 kN/m\({}^{3}\), and the minimum dry weight was 12.43 kN/m\({}^{3}\). The Afterberg limit test showed Non-Plastic (NP) for the Plastic Index(PI). The elastic modulus calculated by shear wave velocity was \(2\times 10^{7}\) Pa. The sample corresponds to SW-SM when classified under the Unified Soil Classification System (USCS). The maximum void ratio was 1.123 and the minimum void ratio was 0.443. The Internal Friction Angle was 27.7\({}^{\circ}\), and the Dilatancy angle was 24.4\({}^{\circ}\). Table 1 summarizes the test results for the basic physical properties of loose ground. In order to create a layered ground of a flat model with two different ground properties, the dense ground was created by mixing soil and silica sand with a diameter of 2-5 mm in a weight ratio of 6:4. The unit weight of the combined sample was 21.5 kN/m\({}^{3}\). For the loose ground sample, the specific gravity test, the particle size analysis test and the standard proctor test were carried out. Since it is mixed soil, Table 2 lists the physical properties required for the experiment. According to the analysis of the grain size distribution curve, the finer content of the sample was 6.48%. The specific gravity of the soil was 2.63, the optimum moisture content of the soil was 8.14%. The maximum void ratio was 0.923, and the minimum void ratio was 0.487. The maximum dry weight was 18.95 kN/m\({}^{3}\), and the minimum dry weight was 14.65 kN/m\({}^{3}\). Figure 1 is the conceptual diagram of the structure and shaking table test equipment used in this experiment. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameter** & **Value** & **Parameter** & **Value** \\ \hline
**No. 200** & 10.8 & **e\({}_{\text{max}}\)** & 1.123 \\
**Passing (\%)** & 2.69 & **e\({}_{\text{min}}\)** & 0.443 \\
**OMC (\%)** & 12.5 & **r\({}_{\text{d max}}\)** & 18.27 \\  & & **(kN/m\({}^{3}\))** & 12.43 \\
**PI (\%)** & NP & **r\({}_{\text{d min}}\)** & 12.43 \\  & & **(kN/m\({}^{3}\))** & \\
**USCS** & SW-SM & **Elastic** & \(2\times 10^{7}\) \\
**Internal** & & **modulus (Pa)** & \\
**friction angle (\({}^{\circ}\))** & 27.7\({}^{\circ}\) & **Dilatancy** & 24.4\({}^{\circ}\) \\  & & & \\ \end{tabular}
\end{table} 
Table 1: Geotechnical index properties of the specimen (loose ground) used in this study ([PERSON] et al. [12]). Figure 1: The experimental system used in this study ([PERSON] et al. [13]). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameter** & **Value** & **Parameter** & **Value** \\ \hline
**No. 200** & 6.48 & **e\({}_{\text{max}}\)** & 0.923 \\
**Passing (\%)** & 2.63 & **e\({}_{\text{min}}\)** & 0.487 \\
**r\({}_{\text{d max}}\)** & 18.95 & **OMC (\%)** & 8.14 \\
**(kN/m\({}^{3}\))** & 14.65 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Geotechnical index properties of the specimen (dense ground) used in this study. In this study, a number of frames that are freely operated in the horizontal direction are composed of soft elements capable of mimicking infinitely extended ground boundary conditions for horizontal shear motion. This flexible structure has dimensions of 200 cm (width) \(\times\) 60 cm (length) \(\times\) 60 cm (height) and consists of 12 layers of aluminum frames. Each frame is 4.5 cm thick and the spacing between frames is about 0.5 cm. Each frame can move independently of each other in horizontal directions through roller bearings.