## 3 Results  
### Recorded Accelerations and Response Spectra  
The recorded horizontal and vertical acceleration during shaking are shown in Figures 14 and 15, respectively. Looking at the surface accelerations (A2), sharp response accelerations occurred earlier at A2-A at about 190 s, indicating that liquefaction of the model occurred first outside of the embankment. The reason for this is that overburden pressure outside of the embankment is smaller in comparison to the soil under the embankment. Since the soil outside of the embankment started to weaken, triggering large displacements and the loss of bearing capacity, the geotextile tube reinforcement was also displaced horizontally as well as vertically. Larger surface accelerations were observed in the embankment soil in comparison to the soil outside of the embankment as the geotextile tube reinforcement was laterally displaced. Furthermore, the surface horizontal accelerations during shaking at A2-C, as shown in Figure 14d, were excessively large at about \(t\) = 250 s to 300 s in comparison to A2-B and A2-D, in which the peak surface acceleration at A2-C was about 6 times the peak input acceleration. The reason for this is that the accelerometer was placed in the open ground, allowing it to freely move horizontally in comparison to accelerometers A2-B and A2-D in which the distinct movements were in the vertical direction (settlement of the foundation). Comparing the surface accelerations A2-B and A2-D, large surface accelerations occurred at longer durations at A2-B than at A2-D. This could be due to the reinforcement and improvement of the foundation soil in A2-D. Sharp vertical accelerations were also observed starting at about 200 s, as shown in Figure 15b,c. It is evident that sharp vertical accelerations started to occur earlier at a longer duration at A2-B than at A2-D as sharp vertical accelerations only started to occur at about 250 s for A2-D. Sharp vertical accelerations indicate the occurrence of foundation subsidence due to liquefaction. A comparison of the state of the shallow foundations before and after shaking is shown in Figure 16, which exhibits large settlement of the shallow foundations. At the end of shaking, the foundation at location B settled to about 13 cm while the foundation at location D settled to about 10 cm. The slight reduction of the foundation settlement may have been a manifestation of the inclusion of a geotextile layer. Figure 14: Recorded horizontal accelerations: (**a**) A1-C, (**b**) A2-A, (**c**) A2-B, (**d**) A2-C, and (**e**) A2-D.  
Figure 15: Recorded vertical accelerations: (**a**) A1-C, (**b**) A2-B, and (**c**) A2-D. The variation of the horizontal elastic response spectra (5% damping) at A1-C, A2-A, A2-B, A2-C, and A2-D is shown in Figure 17. In Figure 17a, it can be seen that at \(t\) = 0-150 s the maximum response accelerations at all accelerometers are almost the same, with the maximum input response acceleration (A1-C) being slightly smaller than the surface response accelerations (A2). This means that at this time range, the surfaces of the scale model have not liquefied. However, at \(t\) = 150-200 s, as shown in Figure 17b, it can be observed that the response accelerations at A2-A, A2-B, and A2-D, have greatly deviated from the input response acceleration (A1-C) while the response acceleration at A2-C (accelerometer at center surface of embankment) only slightly increased. This response may be a result of liquefaction at A2-A (outside zone of embankment). Similar responses from A2-B and A2-D may be caused by the weakening of the ground in which the geotextile tubes were laid, causing the embankment soil near the outside zone to behave similarly to A2-A.