Abstract: Relying on the example of pile-anchor supporting slope in Lanzhou Port Affairs District, the combined approach of wireless automatic monitoring and finite element software numerical simulation was employed to investigate the variations in internal forces and slope stability of the pile-anchor supporting at the stage of no top beam (filling process) and setting of the top beam (during the operation period). The results show that at the stage without top beam, as the height of the fill increases, the pile bending moment, anchor axial force, and slope displacement gradually increase. After the installation of the top beam, the pile bending moment and the anchor axial force can be effectively reduced. The axial force of the anchor rod has a strong restraining effect on the soil near the top of the pile with the most significant constraint effect observed on the top displacement of the slope. The influence of the displacement of the slope gradually decreases from the top of the slope to the bottom of the slope, which also significantly improves the side stability of the slope. With the mutual adjustment of the supporting structure and the slope soil stress during the operation period, the internal force and displacement of both tend to stabilize. This test provides a useful reference for the design, construction, and monitoring analysis of the pile-anchor-supported slopes in the northwest loess area.

Key words: pile anchor, slope, top beam, field test, finite element analysis