## 5 Analysis of the Monitored Results  
### Lateral Deflections of the Enclosure Pile  
Figures 8-11 plot the lateral deflections of the enclosure pile, and four typical monitoring points (i.e., CX5 in pit A, CX26 in pit D, CX28 in pit C, and CX9 in pit B) were selected. Among them, the measuring points within foundation pit A, C, and D (i.e., CX5, CX28, and CX26) were next to foundation pit B. It can be seen from Figures 8-11 that the excavation of the foundation pit caused the lateral deformation of the retaining pile towards the foundation pit. With the excavation of the foundation pit, the lateral displacement of the retaining pile also increased, and the position of the maximum lateral displacement went deeper, which was near the excavation surface. This was mainly caused by the increase in the active earth pressure behind the retaining pile due to the excavation and unloading of earth pressure in the foundation pit. During stage 2 and stage 4, the second and third layers of pits A, C, and D were excavated. Because of the large thickness of the second and third layers of soil in area A, C, and D, and the long excavation duration, the lateral deflections of the enclosure pile increased significantly between stages 2 and 4. Figure 7: Excavation of soil layer 3. Figure 8: Lateral wall deflections of CX5 for the various excavation stages. Figure 9: Lateral wall deflections of CX26 for the various excavation stages. Figure 11: Lateral wall deflections of CX9 for the various excavation stages. Figure 10: Lateral wall deflections of CX28 for the various excavation stages. It can also be seen from Figure 11 that the lateral deflections of the enclosure pile within foundation pit B barely changed during the excavation of foundation pits A, C, and D, which indicates that the excavation of the adjacent foundation pit had little effect on the lateral deflections of the enclosure pile of the unexcavated foundation pit. Figures 8-10 also illustrate that during the excavation of foundation pit B, the lateral displacement of the retaining piles of foundation pits A, C, and D close to foundation pit B first increased and then decreased. The reason for the increase in the lateral displacement was the creep of surrounding soil or, alternatively, the time effect of the retaining structure on the foundation pit. During the excavation of foundation pit B, the long-term exposure of foundation pits A, C, and D caused the increase in the lateral displacement of the retaining pile. But the excavation of soil in foundation pit B reduced the width of soil outside foundation pits A, C, and D, resulting in a reduction of active earth pressure acting on the retaining pile of foundations pit A, C, and D. Then, the reduction in the lateral deformation of the retaining pile was expected due to the stress release caused by adjacent excavation. A similar phenomenon can be found from the measured lateral deflections of the diaphragm wall of a group excavation in Shanghai Expo Park [18]. Since the excavation schedules were different for this study and [18] detailed comparisons at different excavation stages are impossible; thus, they are not made here. According to [18], the lateral deflections of the diaphragm walls between two adjacent excavation pits were significantly less than that of the diaphragm walls along the perimeter of the whole foundation pit group. This was, again, caused by decreased earth pressure on the lateral wall from both sides due to the excavation of the foundation group [18]. Therefore, the adoption of a foundation pit group can reasonably reduce the deflection of the wall between adjacent foundation pits based on the instruments from this study and other similar practices [18]. The maximum lateral deformation of the retaining pile caused by its own excavation is also shown for each foundation pit in Figures 8-11.