关键词: 边坡变形, 边坡稳定性, 支护措施, 导流洞

Abstract: Large deformation, more than 0.5m, had occurred at the side slope of diversion tunnel outlet of a hydropower project during excavation. To analyze and solve the deformation problems，firstly the monitoring datum of slope deformation was analyzed, and the deformation scope and main characteristics were found out. Then, engineering geological method, limit equilibrium method and numerical simulation method were used to study the stability properties of the slope under different phases and different conditions，especially the action mechanism and function of various reinforcement measures in slope stability. The research results indicate that without effective reinforcement, the surface soil layer would slide during excavation; the existing reinforcement can maintain the slope stable under normal condition, however the safety reserve is not enough; in the measure taken at present,some cables and anchor piles are redundant. It's suggested that anti-sliding piles, consolidation grouting and underground water discharging be used to increase the stability of the whole slope.

Key words: slope deformation, slope stability, supporting measures, diversion tunnel