Abstract: The influence of large-diameter slurry-supported bored-pile excavation on slope stability is investigated using a rapid-transit bridge foundation project as a case study. A numerical model is established to analyze the evolution of slope deformation and safety factors during different stages of pile-hole excavation. The results indicate that excavation in the early stages significantly reduces the safety factor of the slope above the pile-top platform, while the impact diminishes in later stages. When the pile hole is located near the rear edge of the slope and maintains sufficient distance from the slope crest, its effect on that slope grade is relatively small. Excavation may alter the failure mode or shift the weak zones of the slope, requiring dynamic control and appropriate monitoring during construction. In engineering practice, pile holes should be positioned away from the slope toe, and casing pipes should be embedded to pass through weak soil layers. When the pile hole is located at the rear edge of the slope, the distance between the hole and the slope crest should be at least three times the pile diameter.

Key words: Pile Installation, Numerical Simulation, Slope Stability, Factor of Safety