## 4 Analysis and Discussion
### Field Monitoring Results of Foundation Pit
#### 4.1.2 Monitoring Results of Deep Horizontal Displacements of the Soil  
Figure 5 shows the deep horizontal displacement in the soil as the foundation pit was excavated to the bottom of the foundation pit. The monitoring points in Figure 5a were located behind the north segment of the diaphragm wall of sub-pit 3A10-1, and the monitoring points in Figure 5b were located behind the west segment of the diaphragm wall of sub-pit 3A10-1. The deep displacements of the soil at different locations showed a parabolic pattern with a large center and two small ends. Except for the monitoring point CX8, where the deep displacement was much smaller than the displacement of the diaphragm wall, the displacements at the other points were closer to the displacements of the diaphragm wall at the approach location. This may be due to the disturbance of the end of the inclinometer tube at monitoring point CX8 by the site construction, which resulted in an overall deflection of the tube towards the outside of the foundation pit. The comparison of the soil displacement pattern and wall deformation pattern at the same locations revealed some differences in the horizontal displacements. The maximum displacement depth of the soil of the north ground wall is lower than the maximum displacement depth of the wall, and the maximum displacement depth of the soil of the west ground wall is higher than the maximum displacement depth of the wall. In fact, the soil was composed of fragmented soil particles, and this difference may be due to soil deformation along the length of the diaphragm wall during the deformation of the diaphragm wall. The difference in the roughness between the supporting wall and the soil may cause a difference in the horizontal deformations of the soil. Due to the use of zonal excavation, the active zone on the west side of the diaphragm wall was pre-built with several diaphragm walls, which limited the deformation of the soil along the length of the diaphragm wall. This was why the maximum depth of burial of the soil displacement of the west ground-connecting wall was slightly higher than the maximum depth of burial of the wall displacement.  
Figure 5c shows the deep soil displacements in the area between the Yuantai Building and the sub-pit 3A10-1. With the exception of monitoring point CX31, which was farther away from the Yuantai Building, the monitoring points for the shallow soil generally orientated towards the outside of the foundation pit and had a certain \"push-back  
Figure 5: Deep horizontal displacements of the soil. (a) 3A10-1 sub-pit. (b) 3A10-1 sub-pit. (c) 3A10-1 sub-pit. (d) 3A10-2 sub-pit. (e) 3A5 sub-pit. (f) 3A8 sub-pit.  
displacement\". As a result of the relocation of the Yuantai Building, the foundations at the base of the building were strengthened, and a ring beam foundation was fabricated. In fact, this reduced the width of the shallow active zone behind the diaphragm wall, so that the shallow soil was pushed back under the action of the diagonal struts.  
Monitored deep displacements of the soil behind the diaphragm wall of sub-pits 3A5 (Figure 5e) and 3A8 (Figure 5f), CX2, CX3, and CX30 showed a similar trend to the aforementioned sub-pits. CX38 and CX26 were close to sub-pit 3A10-1, and foundation pit excavation affected the deformation monitoring at both points. The monitoring results were very discrete, which did not allow for a reliable pattern to be developed.