## 6 Application and Discussion of the Proposed Method
### Prediction of Influenced Zone and Adjacent Tunnel Displacement  
In this project, the strata type within the excavation depth and tunnel buried depth, the supporting structure forms of deep excavation, and the structure form and diameter of the tunnel are consistent with those in the numerical simulations. Therefore, the proposed method obtained from the numerical simulation can be used to predict the influenced zone of deep excavation and the adjacent tunnel displacement.  
In this project, the average excavation depth in the podium building area is \(H_{\text{e}}=22.3\) m, and the vertical and horizontal positions of the up-track tunnel normalized by the excavation depth (\(H_{\text{e}}\)) are \(H_{\text{t}}/H_{\text{e}}=(15+6.2/2)/22.3=0.81\) and \(L_{\text{t}}/H_{\text{e}}=(33+6.2/2)/22.3=1.62\). To predict the influenced zone of deep excavation on adjacent tunnel displacement, it is assumed that the maximum retaining wall deflection is \(\delta_{\text{hm}}=0.18\%H_{\text{e}}\), \(0.3\%H_{\text{e}}\), and \(0.7\%H_{\text{e}}\), respectively. Then, according to the flow chart for predicting the influenced zone shown in Figure 12, the influenced zones of deep excavation were obtained, and the actual position of the tunnel was placed in the influenced zone, as shown in Figure 16.  
It is observed that, under three conditions of \(\delta_{\text{hm}}\), the range outside the deep excavation can be divided into: I (primary influenced zone), II (secondary influenced zone), III (general influenced zone), and IV (weak influenced zone). With the increase of \(\delta_{\text{hm}}\), the scope of the influenced zone gradually expands, especially the scope of the primary influenced zone.  
The up-track tunnel is located in the secondary influenced zone, i.e., the displacement induced by deep excavation may be 10-20 mm.  
Similarly, the average excavation depth in the tower building area is \(H_{\text{e}}\) = 34 m, the vertical and horizontal positions of the up-track tunnel normalized by the excavation depth are \(H_{\text{t}}/H_{\text{e}}\) = (15 + 6.2/2)/34 = 0.53 and \(L_{\text{t}}/H_{\text{e}}\) = (33 + 6.2/2)/34 = 1.06, respectively. According to the displacement control level of the retaining wall, it is assumed that the maximum retaining wall deflection is \(\delta_{\text{hm}}\) = 0.18%\(H_{\text{e}}\), 0.3%\(H_{\text{e}}\), and 0.7%\(H_{\text{e}}\), respectively. Then, according to the flow chart for predicting the influenced zone shown in Figure 12, the influenced zones of deep excavation were obtained, and the actual position of the tunnel was placed in the influenced zone, as shown in Figure 17.  
It is observed that the scope of the influenced zone is further expanded compared with that in Figure 16. The range of 3\(H_{\text{e}}\) outside the pit can be divided into: I (primary influenced zone), II (secondary influenced zone), and III (general influenced zone). The tunnel position transferred from the secondary influenced zone to the primary influenced zone, i.e., the excavation-induced tunnel displacement may exceed 20 mm, and with the increase of \(\delta_{\text{hm}}\), the displacement gradually increases.