## 4 Finite Element Numerical Calculation
### Numerical Analysis Results
#### 4.3.2 Soil Pressure  
Figure 18 shows the displacement cloud of the slope soil, and the deformations were different at different positions on the top plane of slope. The soil displacement near the slope surface decreased significantly, whereas the displacement near the boundary of the slope top is relatively larger. The maximum displacement was 0.142 m under the fifth level of load. The soil displacement above the horizontal plane at the slope foot showed an obvious layered characteristic along the vertical direction. Due to the reinforcement effect of the composite structure and by virtue of the vertical plane at the slope foot where the side pile was located as the interface, the soil displacement variation below the horizontal plane at the slope foot was roughly divided into two parts. In the blue area on the right side, the soil displacement was close to zero, indicating that the soil deformation was basically unaffected. Thus, in a position close to the slope foot, the composite structure could effectively reduce the plastic zone of the slope. However, in the left region, the slope soil had an obvious deformation. Within the zone reinforced by the composite structure, the soil deformation decreased rapidly, and the soil deformation at the slope foot was close to zero. According to the variation regularity of displacement, the spatial arc crown beam composite supporting structure can reduce slope deformation and displacement, and thus landslide risks.  
Figure 18: Displacement cloud of slope soil: (**a**) 30 kPa; (**b**) 60 kPa; (**c**) 90 kPa; (**d**) 120 kPa;(**e**) 150 kPa.  
The soil pressure distribution regularity in the front of pile is shown in Figure 19. Before the plastic soil deformation, the soil pressure in the front of pile provides resistance for the anti-slide pile. The larger the soil pressure in the front of pile, the stronger the resistance effect would be. The soil pressure in the front of pile continuously increased with the load applied on the slope top. In particular, the extreme soil pressures in front of P1, P3, P5, and P6 under the fifth level of load were 856.29 kPa, 162.23 kPa, 133.63 kPa, and 147.03 kPa, respectively. It can be seen that the extreme soil pressure in front of P1 is the largest, and the maximum value appears on the pile top. The results show that soil stabilization at the slope foot can improve the supporting effect of side piles (P1 and P11).  
Additionally, the distribution regularity of soil pressure in front of P3, P5, and P6 was different from that of P1 at the slope foot, which was zero near the upper part of these piles due to the thin soil in front of the pile on the slope surface and the loosened soil in a certain range near the pile top, leading to a separation phenomenon between the pile and the soil. However, the anti-slide piles were still in normal working condition; note that the ultimate displacement of the anti-slide pile was different from that of the pile foundation in the bridge and building foundation. Except for P1, the soil pressure in front of P3, P5, and P6 was larger near the middle and lower parts of those pile, which were less affected by landslide thrust. With the load increase on the slope top, the closer the soil was to the pile top, the faster the soil pressure increased. The overall soil pressure trend decreased, and the pile length influenced by the load was shorter than the designed length. The load transfer mechanism of the slope reinforcement by the spatial arc crown beam composite supporting structure is reasonable, and the stable soil near the slope foot can be used to avoid the destruction of soil in a large area and protect the natural and ecological environment.