## 4 Numerical Simulation
### Simulation Results and Comparative Analysis
#### 4.2.2 Spatial Effect Analysis  
Figure 16 shows the spatial distribution of pit deformation during excavation under several typical working conditions. It can be seen from the figure that, as the advance of the working condition, the amount of surface settlement perpendicular to the edge of the pit and the extent of the occurrence of surface settlement gradually increase. The overall deformation of the pit shows a spatial effect during excavation, with the deformation in the middle of the pit being significantly larger than the deformation in the corners of the pit. The deformation of the pile, as can be seen from Figure 17a, presents obvious spatial characteristics. The horizontal displacement of the pile at the foundation pit's corner is the smallest. With the increase of the distance from the pit corner, the horizontal displacement of the pile gradually increases and reaches the maximum value at a certain distance from the corner. From sections AA\({}_{1}\) to HH, the horizontal displacement curve of the pile changes from \"bow\" to \"belly drum\". Moreover, the curve shape keeps the same \"bow\" from sections AA\({}_{2}\) to KK. It can be seen from Figure 17b that the ground settlement is distributed along the long side with an obvious spatial effect, with the settlement at the pit corner being smaller than that at the middle. The ground settlement perpendicular to the pit edge also has a spatial effect as well: when approaching the middle of the pit, the ground settlement tends to grow at first and then subsequently diminishes. As can be seen from Figure 17c, the axial force of the anchor cable presents a spatial effect consistent with the horizontal displacement of the pile and ground settlement in  
Figure 16: Cloud map of the spatial distribution of pit deformation: (**a**) Case1, (**b**) Case5, (**c**) Case8. Figure 17: Simulation results of different sections: (**a**) Horizontal displacement of piles, (**b**) Ground settlement, (**c**) Axial force. the direction of the long side. Meanwhile, the axial force also presents a certain degree of spatial effect along with the depth of the pit. The distribution curve of axial force is approximately parabolic and reaches its maximum value at the fifth cable. In Figure 17, the horizontal displacement, ground settlement and axial force at section JJ are smaller than that at section BB. Sections JJ and BB are at the same distance from the foundation pit corner. In addition, Figure 13 shows that the displacement of the pile top along the short side is smaller than the long side, while the two sections have the same distance from the pit corner. To a certain extent, the spatial effect of the direction of the short side of the pit is more obvious than that of the long side. As can be seen from Figure 18, the horizontal displacement of the pile top gradually increases from the pit corner to the middle of the long side and remains stable at a certain distance from the pit corner. With excavation cases from 1 to 8, the spatial effect influence range is 3 m, 19 m, 35 m, 48 m, 60 m, 78 m, 92 m, and 92 m, respectively. With the increase of excavation depth, the influence of spatial effect also increases, and the scope of influence is 0-92 m, which is about five times the excavation depth. Beyond this scope, the displacement is almost unchanged. The short side of the pit in this project is greatly affected by the spatial effect. Within 98 m in the middle of the direction of the long side, it is less affected. In this case, it can be calculated according to the two-dimensional strain method. As can be seen from Figure 19, with the excavation and support of the pit, the horizontal displacement of the pile gradually increases, and the deformation tends to be stable at case 7. The shape of the deformation curve changed from \"cantilever\" to \"belly drum\". The maximum value occurs between 6.0-8.0 m, which is about 1/3 of the length of the pile.