Analysis of Multi-Stage Slope Displacement and Internal Force of Supporting Structure of Frame Prestressed Anchor Cable Support

Relying on an engineering case, this study establishes an analysis model using PLAXIS 3D and GeoStudio, and compares and analyzes the slope deformation and internal force of the supporting structure with different slope grades and different platform widths at the same height. The results show that the greatest displacement manifests in the lower segments of the slope, which is 12.99 mm, and the maximum anchoring force manifests in the mid-level and lower segments of the slope, which is 288.1 kN. A close correlation is observed between the simulated horizontal displacement of the slope, the maximum axial force of the anchor cable, and the corresponding field measurement results, indicating that the model parameters are satisfactory and that the resulting calculations are reliable. In consideration of the comprehensive stability of the slope, the stability coefficient increased by approximately 1.42% with two-stage slope support and by about 3.48% with four-stage slope support. The axial force of anchor cables was reduced by around 9.5% under two-stage grading, while four-stage grading decreased the maximum axial force of the middle–lower anchors by nearly 27%. The distance between the entrance and exit of the overall sliding surface and the slope surface also decreases with the increase in slope grading and platform width. This study systematically evaluates the combined effects of slope grading, platform width, and frame prestressed anchors. When site conditions permit, slope grading should be prioritized over simply widening the platform, as grading more effectively enhances slope stability and reduces anchor cable loads.