## 3 Calculation Results and Analysis  
### Analysis of Calculation Results in Case 1  
The horizontal and vertical displacement maps of settlement amounts of the hanging wall of the ground fissure of 10 cm, 20 cm, 30 cm, 40 cm, and 50 cm are shown in Figure 2. It can be seen that when the settlement amount of the hanging wall increases, the displacement and deformation of the soil and the overpass increase, and their displacement and deformation are related to the relative position of the ground fissure. The closer the horizontal displacement is to the ground fissure, the greater the impact, and the farther the horizontal displacement is from the ground fissure, the smaller the impact. The maximum vertical displacement is near the middle span. In the analysis of the influence of the change in settlement amount in the hanging wall of the ground fissure on the bridge pier displacement and deformation, the vertical direction displacement difference between the top and bottom of the pier is very small due to the stiffness of the bridge pier and could be ignored; therefore, only the displacement of the top and bottom of the pier in the horizontal direction is considered. The horizontal displacement of the top and bottom of each pier is shown in Table 3. With the displacement difference between the top and bottom divided by the height of the pier, the inclination of each pier under different settlement amounts can be obtained as shown in Figure 3.  
The piers are numbered sequentially from the lower plate to the hanging wall. The tilt of Pier No. 4 in the hanging wall of the ground fissure is the largest during settlement, and the tilt is 0.51% when the settlement is 50 cm; Pier No. 1 in the lower plate of the ground fissure is the second largest, and the tilt is 0.32% when the settlement is 50 cm; Pier No. 3 in the hanging wall has a tilt of 0.24% when the settlement is 50 cm; for Pier No. 2 in the hanging wall, the pier tilt is the smallest; when the settlement is 50 cm, the tilt is 0.12%. The Specification for the Design of Foundations and Foundations for Highway Bridges and Culverts (JTG D63-2019) stipulates that the pier inclination should not exceed 0.2%. It is observed that when the vertical settlement of the ground fissures exceeds 20 cm, the tilt of the bridge pier may exceed the specification requirement. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Vertical Settlement /cm**} & \multicolumn{2}{c}{**Bridge Pier 1**} & \multicolumn{2}{c}{**Bridge Pier 2**} & \multicolumn{2}{c}{**Bridge Pier 3**} & \multicolumn{2}{c}{**Bridge Pier 4**} \\  & **Top** & **Bottom** & **Top** & **Bottom** & **Top** & **Bottom** & **Top** & **Bottom** \\  & **Displacement** & **Displacement** & **Displacement** & **Displacement** & **Displacement** & **Displacement** & **Displacement** & **Displacement** \\  & **/mm** & **/mm** & **/mm** & **/mm** & **/mm** & **/mm** & **/mm** & **/mm** \\ \hline \(10\) & \(-0.256\) & \(-0.259\) & \(-0.713\) & \(-1.371\) & \(-0.388\) & \(-0.618\) & \(-0.328\) & \(0.248\) \\  
By extracting the displacement data of the box girders, the difference in horizontal direction displacement between the left and right parts of the box girders at different settlement amounts produced by the hanging wall of the ground fissure is very small and could be ignored; hence, only the displacement of the box girders in the vertical direction is analyzed. The vertical displacement of the nodes at the left and right end positions of the  
Figure 2: Overall displacement map under different settlements of the hanging wall of the ground fissure: (**a**) S = 10 cm; (**b**) S = 20 cm; (**c**) S = 30 cm; (**d**) S = 40 cm; (**e**) S = 50 cm.