## 5 Numerical Analysis Results and Discussion
### PLAXIS Analysis
#### 5.3.1 Case Simulation of Site 1  
Table 4 displays the soil properties for Site 1, Tables 5 and 6 display the material parameters of Site 1's slope protection structures, and Figure 13 displays Site 1's analysis model. The blue line represents simulated free-form lattice beams, the yellow line represents simulated RC curtain walls, the blue arrows represent the pavement load, and the pink parts represent simulated grouted anchor bars. From top to bottom, the soil layer was separated into two layers: sandstone and worn rock. The inhomogeneity of the geotechnical materials at Site 1 results in an uneven displacement field in the slope. Table 7 displays the displacement of Site 1 in each scenario. Contour line diagrams of the slope displacement in various scenarios are displayed in Figures 14-16. Areas based on the same displacement present a series of spatial surfaces, namely, displacement isosurfaces [43]. The density of the isosurface represents the change in displacement [23]. The main effect of water pressure on the slope sliding surface is to reduce the normal pressure or force at the soil particle-to-particle contact. As seen in Figure 14, the forces acting on Site 1's slope are focused on the slope's sliding surface at normal groundwater levels. In comparison, Figure 15 shows that the forces acting on the slope rise to the top of the slope at high groundwater levels. This is because high water tables increase the pore water pressure, resulting in lower shear resistance in potential failure planes and thus increasing the risk of slope failure [21]. One of the most frequent major dynamic pressures on slopes is earthquakes. The rock and soil on the slope are under a great deal of dynamic stress [44]. Slope stability is thus significantly impacted by earthquakes. The pseudo-static analysis of Site 1 indicated that the force acting on the slope extended from the top to the sliding surface when seismic loading was added, as seen in Figure 16. It can be seen from the figure that the isosurfaces were densely distributed near the sliding surface. Furthermore, the closer to the free surface of the slope, the greater the magnitudes of the isosurface. It is worth noting that dense areas always represent localized surface failures. Overall, the above results are consistent with the existing literature [12; 21; 23]. The potential sliding surface based on safety analysis is particularly useful for observing the localization of deformations within the soil when failure occurs [39]. Figures 17-19 show the potential sliding surface based on safety analysis in different scenarios at Site 1. Potential failure surfaces in a slope model can be identified through the density of contour lines [45]. Furthermore, Figure 20 shows the shading distribution diagram of the \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**scenarios**} & l u l & \multicolumn{2}{c}{\(u_{x}\) (mm)} & \multicolumn{2}{c}{\(u_{y}\) (mm)} \\ \cline{2-5}  & **(mm)** & **Max** & **Min** & **Max** & **Min** \\ \hline Normal groundwater level & 3.86 & 1.62 & \(-\)0.30 & 3.56 & \(-\)0.50 \\ High groundwater level & 3.26 & 1.69 & \(-\)0.47 & 2.82 & \(-\)1.13 \\ Normal groundwater level and & 24.10 & 0 & \(-\)20.54 & 2.46 & \(-\)13.53 \\ pseudo-static analysis & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Displacement of Site 1 in various scenarios. Figure 16: Contour line diagram of total displacement with normal groundwater level and pseudo-static analysis for Site 1. Figure 15: Contour line diagram of total displacement with high groundwater level at Site 1. The safety factor (SF) of a slope is the comparison of resistance and driving force, which can reflect the condition of the slope [29]. In slope stability analysis research, SF plays an important role in evaluating slope stability. [PERSON] proposed Table 8 based on several landslide events [46].