In this study, the stability analysis of slope failure that occasionally occurs when rain falls was carried out. This paper focuses especially on the stability of large-scale cut slope exposed to heavy rainfalls. The study was carried out on a cut slope which is 52 meters high and consists of soil and rock. Gradual landsliding is in progress due to continual heavy rainfalls. This paper describes slope stability analyses performed to assess the appropriate methods of stabilization. For the numerical analyses, the slopes were divided into several parts by soil layers, slope height, and the scale of the landslide. As a result, two different types of stabilization methods are recommended according to the condition of the cut slope and the working area. For slopes with relatively low height and enough working area, it is recommended that retaining walls are constructed at the lower end of the cut slope and soil-nailing method is applied to flatten the slope. For the other slopes, soil-nailing method is recommended.
At a highway construction site in the middle west part of Korea, landslides of large-scale soil and rock slopes have occurred due to intense rainfalls. Therefore, proper stabilization methods were required to allow construction continue. The studied slopes are largely excavated ones, which consist of soil and rock layers. Landslides were gradually developing, so the exact areas of landslide and future movements were unpredictable. Based on the information gained from geologic site exploration of the failed slopes, the slopes were divided into several cross-sections (zones for analysis). For each cross section, slope stability analysis was carried out and suitable stabilization methods were proposed.
According to geological investigation, from the ground surface the distribution of strata is alluvial soil layer, weathered soil, weathered rock and soft rock.