## 4 Conclusions  
In this study, a simple shaking table apparatus was developed to investigate the behavior of shallow foundations laid on a liquefiable embankment. Based on the results of the experiment, the following conclusions are drawn:  
* The liquefaction of the embankment was a reaction to the liquefaction of the outside soil as water seeped into it, showing the susceptibility of Saemangeum silty sand to seepage-induced liquefaction, even at a partially saturated state. It was observed that at \(t\) = 0 s to 200 s, pore pressure rise at PP-B and PP-D of the embankment was negligible. A sudden rise in pore rise was then observed at \(t\) = 200 s to 300 s.
* Larger surface accelerations were observed in the embankment soil in comparison to the outside soil, indicating the importance of analyzing the liquefaction potential of soils not only at the site area but also near embankments because this could cause severe damage to structures inside the embankment. The surface horizontal accelerations during shaking at A2-C were excessively large at about \(t\) = 250 s to 300 s, which reached a maximum surface acceleration of 1.15 g, about 6 times larger than the input acceleration.
* Although higher excess pore water pressures were experienced earlier at location D, the shallow foundation at location D sustained slightly lesser damage, which could be mainly due to the effect of the geotextile and soil improvement. The settlement of the shallow foundation was reduced by 3 cm due to the addition of geotextile and soil improvement.
* Since higher excess pore water pressures were experienced earlier at location D, it is recommended to use a more permeable geosynthetic reinforcement to lower the rise in pore pressure during shaking.
* Further studies regarding the cost-effectiveness and advantages of geosynthetics are recommended.
* An experiment conducted by the authors on a dry embankment resulted in cracks and severe inertia-induced damage to the shallow foundations. Hence, the state of the embankment will result in different damages.  
Conceptualization, H.-J.K.; supervision, H.-J.K.; methodology, H.-J.K., P.R.D., T.-W.P., and H.-S.K.; investigation, T.-W.P., H.-S.K., P.R.D., J.V.R., and H.-S.C.; formal analysis, P.R.D. and H.-S.C.; writing--original draft preparation, P.R.D.; writing--review and editing, J.V.R.; project administration, H.-S.K.; funding acquisition, H.-J.K. and T.-W.P. All authors have read and agreed to the published version of the manuscript.  
Figure 22: Shear stress-shear strain relationships: (**a**) point 1 at \(t\) = 0–175 s, (**b**) point 1 at \(t\) = 175–300 s, (**c**) point 2 at \(t\) = 0–175 s, (**d**) point 2 at \(t\) = 175–300 s, (**e**) point 3 at \(t\) = 0–175 s, and (**f**) point 3 at \(t\) = 175–300 s.  
**Funding:** This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A1A0304518511, NRF-2020R11A3A04036506). The APC was also funded by the National Research Foundation of Korea (NRF-2021R1A6A1A0304518511).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data generated or analyzed during this study are available from the corresponding author upon reasonable request.  
**Conflicts of Interest:** The authors declare no conflict of interest.