# Model Test on the Behaviors of Deep Excavation with Lateral Confined Water
## 3 Results
### Analysis of Vertical Displacement of the Ground Surface  
The vertical displacement curves of the ground surface are shown in Figure 15, with positive and negative values representing uplift and settlement, respectively. The ground surface vertical displacement is predominantly characterized by uplift and follows a groove-shaped distribution, which is similar to the surface deformation curve observed in confined aquifer excavations, as reported by [PERSON] and [PERSON] et al. [22]. Due to the differences in soil layer compaction on both sides of the pit, the maximum settlement locations of the left and right ground surfaces are 150 mm (0.50\(\%D\)) and 250 mm (0.83\(\%D\)) from the pit edge, respectively. When the lateral confined water level is raised to 396 mm (O), friction between the soil and the wall caused by the confined aquifer pressure leads to the upward displacement of the soil [23]. Consequently, the ground surface outside the pit experiences overall upward uplift. The vertical displacement of the ground surface stabilizes at approximately 10 mm on the left side and 8 mm on the right side. As excavation depth increases (K1-K4), the unloading effect of the soil excavation causes an increasing inward displacement of the diaphragm wall. However, after the installation of struts, the vertical displacement of the ground surface also decreases. This is because the struts restrict the inward displacement of the diaphragm wall more significantly near the depth of the wall than at the wall top (Figure 12). After excavation reaches the bottom of the pit, the vertical displacements of the ground surface on both the left and right sides decrease to between \(-1.19\) mm and 4.20 mm. Upon further raising the lateral confined water level to 432 mm (F), the increase in pore water pressure causes uplift in the overlying soil, which causes the uplift of the ground surface again. However, vertical displacement changes further from the diaphragm wall monitoring points are more pronounced. This is because the rise in the lateral confined water level induces wall-soil interaction, causing  
Figure 14: Horizontal displacement duration curves of the diaphragm wall at 275 mm depth. the diaphragm wall to shift inward under the unbalanced pressure on both sides of the wall (Figure 12). This results in a reduction in horizontal stress in the surrounding soil, leading to soil loss behind the wall and causing a localized settlement of the ground surface near the diaphragm wall. For instance, the vertical displacement at 100-250 mm from the diaphragm wall is smaller than that at 300-450 mm from the wall. Discussion: Influence Mechanism of Lateral Confined Water on Strut Axial Force and Diaphrag Wall Deformation  
Section 3 analyzed the effects of lateral confined aquifer pressure on pit excavation characteristics. To further explore the mechanisms of lateral confined aquifer pressure on strut forces and diaphragm wall deformation, Section 4 discusses the response changes of each strut and the diaphragm wall when the lateral confined water level (\(H_{c}\)) is raised from 396 mm to 432 mm (F). Figure 16 compares the changes in strut axial forces at lateral confined water levels of 396 mm and 432 mm. When the lateral confined water level is raised to 432 mm, the axial force of the fourth level of strut increases from 349 N to 528 N, a 51.3% increase, while the axial forces of the other struts remain almost unchanged. The lateral confined aquifer layer is surrounded by low-permeability clay layers (improvious layers), which are close to the model box wall or the ground connection wall, with no seepage pathways. Therefore, when the lateral confined water level rises, pore water pressure is generated in the highly permeable fine sand layer (confined aquifer), without infiltrating into the clay layers. Under the weight of the overlying soil, the horizontal pore water pressure acts on the diaphragm wall, causing it to shift inward.