# Evaluating the Effects of Deep Excavation on Nearby Structures Through Numerical Simulation
## 3 Numerical Simulation Analysis and Verification
### Analysis Results and Case Validation  
In this study, all soil layers were analyzed using the MC, HS, and HSS models. Structural loading was analyzed using the plate elements. The numerical simulation results from PLAXIS were compared with field observations. Figures 5-7 show a comparison between the numerical analysis results and the field observations for inclinometer SID1 at various excavation stages. According to statistical analysis of the field data, the maximum deformation of the wall was 6.17 mm inward (negative values indicate outward deformation) at a depth of 14 m upon completion of the final excavation stage. Comparing this with the numerical analysis results for the same excavation stage, the numerical analysis revealed that the MC model showed a maximum deformation of 6.67 cm at a 14.2 m depth, the HS model showed 30 cm at 16.4 m, and the HSS model showed 18.95 cm at 16.4 m. In Appendix A, Figures 11 and 10 show the field observation data for inclinometer SID3, with the maximum deformation occurring upon the completion of the fifth layer of support. The numerical analysis showed that the MC model had a maximum deformation of 6.31 cm at a 6 m depth, the HS model had 18.8 cm at 16.4 m, and the HSS model had 11.2 cm at 16.4 m. The data mentioned above are summarized in Table 3. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Neighboring Building Floor** & **Total Number of Floor** &
\begin{tabular}{c} **Unit Weight** \\ **(kPa/Floor)** \\ \end{tabular} & **Load Increase Coefficient** & **Total Load (kPa)** \\ \hline
12 FB2F & 15 & 10 & 1.3 & 195 \\
5 FB1F & 7 & 10 & 1.3 & 91 \\
4 FB1F & 6 & 10 & 1.3 & 78 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Conversion of neighboring building loads to ground loading. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Maximum** & **Validation** &
\begin{tabular}{c} **Field** \\ **Observation** \\ \end{tabular} & **MC** & **HS** & **HSS** \\ \hline \multirow{3}{*}{SID1} & Construction stage & \multicolumn{3}{c}{Final excavation (excavation to GL\(-\)15.8 m)} \\ \cline{2-6}  & Maximum lateral deformation (mm) & 6.17 & 6.67 & 30 & 18.95 \\ \cline{2-6}  & Depth (m) & 14 & 14.2 & 16.4 & 16.4 \\ \hline \multirow{3}{*}{SID3} & Construction stage & \multicolumn{3}{c}{Completion of the 5 th layer of support (excavation to GL\(-\)13.2 m)} \\ \cline{2-6}  & Maximum lateral deformation (mm) & 6.61 & 6.31 & 18.8 & 11.2 \\ \cline{2-6}  & Depth (m) & 13 & 6 & 16.4 & 16.4 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Numerical analysis of the maximum lateral deformation of the diaphragm wall. Figure 5: Comparison of inclinometer SID1 and numerical analysis results at each excavation stage (MC model). Figure 6: Comparison of inclinometer SID1 and numerical analysis results at each excavation stage (HS model). Figure 7: Comparison of inclinometer SID1 and numerical analysis results at each excavation stage (HS model). Comparing tfthe above statistical data and the lateral deformation charts for each excavation stage shown in Figures 5-7 and A1-A3, the maximum deformation obtained from the MC model analysis closely matched the field observations. The HS model tends to overestimate the maximum deformation, while the HSS model provides a middle ground: conservative but not excessively overestimating deformation. The HSS model was thus more conservative and rigorous, aligning with previous related studies. However, the depths of maximum deformation from field observations occasionally did not match the simulation results. This discrepancy may be due to factors such as construction practices, geological conditions, observation errors, and input parameters. The maximum deformations from both field observations and numerical analyses were all less than the warning threshold of 40 mm, indicating that the method used in this study was feasible for analyzing the safety and appropriateness of foundation excavation.