## 2 Materials and Methods
### Shaking Table Apparatus and Scale Model Setup  
The actual photo of the shaking table, the scale model test setup, and parts of the shaking table are shown in Figures 10 and 11. Instead of rollers, the table is supported by 12 springs to allow vertical and horizontal movements. Two springs were also installed at the sides of the table to prevent rocking of the test tank, as shown in Figure 11a. The springs have a spring constant of 49.8 N/mm, a diameter of 7 cm, and a height of 30 cm. Although the table could move in three directions (x, y, z), transverse movement was restricted by installing cylindrical bars to achieve a plane strain condition. Glass strips were installed at the sides of the table near the location of the cylindrical bars to reduce friction between the bars and the table. For easy transportation or relocation of the apparatus, rollers or wheels were installed at the bottom of the shaking table. To secure the apparatus in place, as well as to balance or level the table, balance rods were also installed, as shown, which can be adjusted to be able to increase or decrease the elevation of the table. On top of the shaking table is a test tank with dimensions of 3.0 m in length, 0.7 m in height, and 0.7 m in width. At the bottom of the test tank, three translucent hoses were installed at equal space intervals to allow checking and adjustment of the water table. For easy viewing of the test specimen, the front and back of the test tank were made of transparent glass. Non-flexible Styrofoam with a thickness of 2 cm were placed within the box at the sides to reduce the reflection of energy associated with rigid boundary conditions. Figure 8: Scanning Electron Microscopy (SEM) of Saemangeum dredged sand. Figure 9: Composition of Saemangeum dredged sand based on X-ray Diffraction Analysis. Figure 11: Shaking table test: (**a**) scale model test setup, and (**b**) isometric view of shaking table. Figure 10: Actual photo of shaking table test. As a preliminary experiment, a 5 cm thick coarse sand (2 mm in diameter) layer was added at the bottom of the tank, and a 10 cm thick silty sand layer was laid on the top of the coarse sand layer, as shown in Figure 12. Water was added until the water level was 30 cm above the silty sand layer. Thereafter, a shaking table test was conducted. Due to the waves formed by shaking, the upper soil layer was deformed, and a wavelike ground surface was formed. The deformation is caused particularly by Rayleigh waves, in which the surface layer of the ground experienced a combination of vertical and horizontal vibration. The preliminary test shows the difference in the seismic loading between conventional roller type shaking tables and the spring type shaking table used in the test. Before placing the soil sample in the tank, the inner walls were lubricated to minimize soil adhesion. The method of preparing the model ground is similar to the methods by [PERSON] and [PERSON] [43] and [PERSON] et al. [44], in which dry sand is rained over the tank using a sieve. Sample preparation was done by initially filling the test tank with water to a depth of 5 cm. Thereafter, oven-dried sand was poured into a mesh screen that was placed at the very top of the test tank. The sample was sieved to maintain a uniform mass, and then was spread manually by hand as the sand deposit started to accumulate at the bottom of the test tank. The process was repeated until the height of the deposited soil was 45 cm. The embankment was then constructed using oven-dried sand, and pore pressure gauges (PP-B and PP-D) were installed 5 cm below the crest of the embankment. The embankment was reinforced by geotextile tubes with a height of 10 cm. The geotextile used was woven polyester, and its properties are summarized in Table 2. The scale of the embankment is 1:35.