## 4 SoilWorks Numerical Simulation
### Sensitivity Analysis
#### 4.2.2 Assumed Cases  
To understand the sensitivity of the geological parameters on the displacement, stress, or axial force of the retaining wall in the SoilWorks program, reference is made to the cases studied by [PERSON] et al. [24] and [PERSON] et al. [26] using the RIDO and PLAXIS programs, respectively. Hypothetical cases representing sand and clay soils are established for the subsequent sensitivity analysis. * Basic Case Description for Sandy Soil Layer
* Analysis Assumptions
* The length and width of the excavation area are both 40 m, with a depth of excavation of 12 m (H1) and a depth of wall penetration of 10 m (H2). The total length of the continuous wall is 22 m.
* The analysis model adopts a symmetric single-side mode, with a horizontal analysis length (B) of half the original excavation length, which is 20 m. Considering the influence range of the backside of the retaining wall, a distance of at least four times the excavation depth (R = 12 \(\times\) 4 = 48 m) is considered. The vertical range (D) is taken as the length of the continuous wall (H1 + H2) plus twice the penetration depth (H2), assuming a uniformly distributed load of 10 kN/m\({}^{2}\) acting on the ground surface. The detailed model diagram for the simulated case analysis is shown in Figure 6.
* Considering the excavation depth, support system configuration, and soil layer boundaries, a complete analysis mesh is established. The boundary elements of the mesh are assumed to have no horizontal or lateral displacements outside the influence range. * The retaining wall is simulated using beam elements, with the stiffness reduced by 70% based on general empirical values. The input parameters used in the analysis are detailed in Table 13.
* The support system is simulated using truss elements, with the stiffness reduced by 50% based on general empirical values. The input parameters used in the analysis are detailed in Table 14.
* The analysis is conducted using 15-node triangular elements. * Geology and Groundwater  
The sandy soil layer is divided into layers with a thickness of 10 m each. There are a total of 5 layers, and the soil parameters for each layer are detailed in Table 15. The initial groundwater level is assumed to be 1 m below the ground surface. * Basic Case Description for Clay Soil Layer (1) Analysis Assumptions A. The length and width of the excavation area are both 40 m, with a depth of excavation of 12 m (H1) and a depth of wall penetration of 12 m (H2). The total length of the continuous wall is 24 m. B. The analysis model adopts a symmetric single-side mode, with a horizontal analysis length (B) of half the original excavation length, which is 20 m. Considering the influence range of the backside of the retaining wall, a distance of at least four times the excavation depth (R = 12 \(\times\) 4 = 48 m) is considered. The vertical range (D) is taken as the length of the continuous wall (H1 + H2) plus twice the penetration depth (H2), assuming a uniformly distributed load of 10 kN/m\({}^{2}\) acting on the ground surface. The detailed model diagram for the simulated case analysis is shown in Figure 7. C. Considering the excavation depth, support system configuration, and soil layer boundaries, a complete analysis mesh is established. The boundary elements of the mesh are assumed to have no horizontal or lateral displacements outside the influence range. D. The retaining wall is simulated using beam elements, and the input parameters used in the analysis are detailed in Table A3. E. The support system is simulated using truss elements, and the input parameters used in the analysis are detailed in Table A4. F. An analysis is conducted using 15-node triangular elements. (2) Geology and Groundwater  
The clay soil layer is divided into layers with a thickness of 10 m each. There are a total of 5 layers, and the soil parameters for each layer are detailed in Table A6. The initial groundwater level is assumed to be 1 m below the ground surface.