Abstract: The stability of the slope at the left abutment of abutment of a reservoir is evaluated in this paper. The overburden soil layer is above elevation of 1548.0 meters. The bedrock daylights the abutment slope. During the construction, tensile open cracks were observed at the rear of the slope. It is also observed that shear cracks distributed along the front toe of the slope. It is concluded that this soil movement was triggered by the vibrations from the compaction roller and other construction equipment. The original soil structures were destructed by the excessive vibrations. The lapse of the slope supporting measures could not eliminate the gradual deformation of the slope. The tensile cracks at the crown of the slope are widened and result in a landslide. The slide body was three dimensional monitored and evaluated by using the site specific geotechnical parameters. The impact of this slide on the adjacent buildings is also evaluated in this paper. The results indicate that, the slide body is marginally stable and the slope failure is likely under the heavy rain condition. The engineering mitigation is needed on the slide body. Due to the small scale of the slide body, the impact on the adjacent buildings is negligible and the slopes behind the slide body are stable.

Key words: Landslides, Deformation Monitoring, Soil Slopes, Development Mechanism, Stability Analysis