## 5 Results and Discussion  
### Field Monitoring Results  
All monitoring instruments installation finishes before shield tunneling from starting well. The deformation of the diaphragm wall and the ground heave data are recorded from the start of the tunnel through to the diaphragm wall. Figure 9 shows the variation of ground heave of some typical deformation monitoring points (DB-1, DB-2, DB-3, DB-4, and DB-5) with time. Because the monitoring section A-A\({}^{\prime}\) is symmetrical to section B-B', monitoring points DB-1, DB-2, DB-3, DB-4, and DB-5 are selected to analyze the deformation mechanism of Yuanlin Road station when Line 12 passes through the underground diaphragm wall. The ground shows a tendency of upward deformation in the process of shield tunneling. Additionally, three deformation stages of slope were observed from Figure 9, namely the initial deformation stage, rapid deformation stage, and slow deformation stage. In the initial shield excavation stage, the ground deformed at a low rate because of the small volume of excavation. After 7 days, the tunnel for Line 12 was excavated rapidly, and close to Yuanlin Road station of Line 4, which leads to the deformation rate at the surface monitoring points increasing dramatically. When tunnels pass through diaphragm walls, the ground heave suddenly increases, and then shows a temporary stability. After the tunnel for Line 12 passed through the diaphragm wall, the deformation values of monitoring points DB-1, DB-2, DB-3, DB-4, and DB-5 were 4.1 mm, 6.2 mm, 7.53 mm, 7.92 mm, and 6.72 mm, respectively. Overall, the ground heave is small, which did not affect the stability of Line 4. Figure 8: (**a**) Installation instruction of deformation monitoring points; (**b**) installation instruction of diaphragm wall top monitoring points. Likewise, the monitoring results of the top vertical wall deformation of CX-1, CX-2, CX-3, and CX-4 are plotted in Figure 10. Overall, three deformation stages are observed to be the same as that of the ground heave. An initial small deformation lasts 25 days, which is longer than that of the ground heave. The main reason is that the high stiffness of the diaphragm wall leads to its smaller deformation response, compared to the ground heave response. Additionally, the diaphragm wall produces a large deformation when Line 12 passed through the wall. As shown in Figure 10, after tunnel Line 12 passed through the diaphragm wall, the vertical deformation values of monitoring points CX-1, CX-2, CX-3, and DB-4 are 0.21 mm, 0.1 mm, 0.15 mm, and 0.5 mm, respectively. Figure 11 shows the horizontal deformation result of typical monitoring points ZL-1 and ZL-2 in section A-A\({}^{\prime}\) during tunneling of Line 12. The main horizontal deformation of diaphragm wall tendency of monitoring points is consistent with the vertical deformation. The direction of horizontal deformation of the diaphragm wall is adjacent to Yuanlin Road station. After tunneling for 43 days, the horizontal deformations of monitoring points ZL-1 and ZL-2 are 6.81 mm and 4.71 mm, respectively. Figure 10: The monitoring results of wall top vertical deformation of CX1–CX4. Figure 9: The monitoring results of ground heave of DB1–DB5. Day 38 is when Line 12 passed through the underground diaphragm wall. ### Field Monitoring Results  
According to the proposed deformation calculation method, the deformation of the diaphragm wall and Yuanlin Road station of Line 4 is determined. The value of additional thrust \(P\) can be taken as 20 kPa [43; 44; 45]. Table 2 lists the calculated mechanical parameters of ground deformation. C30 concrete was used to construct the diaphragm wall. The value of \(m\) and \(n\) in Equation (4) affects the calculation accuracy of the proposed method. To determine optimum value of \(m\) and \(n\), more than 100 trial calculations are conducted. The values of \(m\) and \(n\) vary from 3 to 20 in trial calculations. Figure 12 shows the deformation of the wall acting on additional thrusts under different \(m\) and \(n\).