## 4 Results and Discussion  
### Lateral Wall Deflection  
Figure 3 shows the deformation contour image of the diaphragm wall after each stage of excavation. It can be seen that the adjacent pit excavation has different effects on the deformation of the diaphragm wall at different positions of the excavated pit. Subsequent excavation will increase or reduce the existing deformation of the diaphragm wall. After the excavation of all pits, the maximum horizontal deformation of the diaphragm wall is located in the arc section of Pit C, followed by Pit A. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Calculation Step** & **Construction Stage** & **Construction Process** \\ \hline
0 & & Initial stress equilibrium \\
1 & & Construction of surrounding buildings \\
2 & & Construction of diaphragm walls \\
3 & & Dewatering (level 1) \\
4 & & Excavation (level 1) \\
5 & & Casting the struts (level 1) \\
6 & & Dewatering (level 2) \\ \(\cdots\) & & \(\cdots\) \\
29 & & Construction of diaphragm walls \\
30 & & Dewatering (level 1) \\
31 & & \(\cdots\) \\
32 & & Excavation (level 1) \\
33 & & Casting the struts (level 1) \\ \(\cdots\) & & Dewatering (level 2) \\ \(\cdots\) & & \(\cdots\) \\
48 & & Construction of diaphragm walls \\
49 & & Dewatering (level 1) \\
50 & & \(\cdots\) \\
51 & & Casting the struts (level 1) \\
52 & & Dewatering (level 2) \\ \(\cdots\) & & \(\cdots\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Simulated construction schedule. In order to conveniently illustrate the coupling effect on the deformation of the diaphragm wall, the deformation data of the diaphragm wall at about half of the excavation process and at the end of each process are selected. The selected construction processes are shown in Table 5. The maximum lateral deformation value of the diaphragm wall of each pit is taken as the representative, and the extracted positions are shown in Figure 4.  
Figure 5 shows the lateral deflection curve of the diaphragm wall at different extracted positions of the foundation pit group. It can be seen that the lateral deformation shape is generally consistent, appearing as a \"bow\". The concrete support at the top of the diaphragm wall limits the lateral deflection, and the base of the wall is embedded into the rock layer, restricting the deformation of the base as well. The maximum lateral deformation of the diaphragm wall is 102.9 mm at C-3. The maximum lateral displacement of the diaphragm walls at A-1, A-2, and C-3 is about 2/3 of the excavation depth. As the concrete cushion is cast at the bottom of Pit C, the buried depth of the maximum lateral displacement at C-4 is 10 m below the excavation surface. The maximum lateral displacement at B-5 and B-6 occurs near the excavation surface of pit-in-pit. Figure 4: Maximum lateral deflection position (A-1, A-2, C-3, etc. are position numbers). Figure 3: Lateral deflection of diaphragm wall. \begin{table}
\begin{tabular}{c c} \hline \hline
**Construction Stage** & **Excavation Depth** \\ \hline Stage 1–1 & Pit A is excavated to \(-15\) m. \\ Stage 1–2 & Pit A is excavated to \(-29\) m. \\ Stage 2–1 & Pit B and Pit C are excavated to \(-15\) m. \\  & Pit B is excavated to \(-22\) m and pit-in-pit is \\ Stage 2–2 & excavated to \(-29\) m. Pit C is excavated to \(-23.8\) m \\  & and pit-in-pit is excavated to \(-27.7\) m. \\ Stage 3–1 & Pit D and Pit E are excavated to \(-15\) m. \\  & Pit D is excavated to \(-22\) m. Pit E is excavated to \(-23\) m. \\ Stage 3–2 & Pit F is excavated to \(-4.5\) m. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The selected construction processes. It can be seen from Figure 5a,b that from Stage 1-2 to Stage 2-2, the maximum lateral displacement at A-1 increases from 50.36 mm to 52.77 mm, with an increase of about 4.8%. In addition, the maximum lateral displacement at A-2 increases from 65.71 mm to 84.22 mm, with an increase of about 28.2%. It can be concluded that the process of Stage 2 has a greater impact on the displacement of the diaphragm wall at A-2.