A preliminary study on the location of the stabilizing piles for colluvial landslides with interbedding hard and soft bedrocks

- A quantitative model is proposed to describe driving force of colluvial landslides.
- Impact of hard layer bedrock on piles relies on location coefficient of hard layer.
- A method is developed to calculate the pile deformation in multi-layer bedrocks.
- Mechanical response of piles is obtained considering alternate hard and soft bedrocks.
- Top and bottom thick hard layers correspond to optimal location for piles.

The paper presents a study on the location determination of stabilizing piles in colluvial landslides with the interbedding of hard and soft bedrocks. A double-arc model is proposed to describe the shape of sliding surface of colluvial landslides, and the corresponding slope surface can be divided into three types, namely the concave type, straight line type, and convex type, respectively. The driving force of colluvial landslides and interbedding characteristics of hard and soft bedrocks are two important factors affecting the determination of optimal location for stabilizing piles. The results indicate that the stabilizing effect of the piles mainly depends upon the hard bedrock. The effect of the location of hard layer bedrock on the pile deformation is represented by the location coefficient. It is found that the optimal location of stabilizing pile locates where both top and bottom hard layers are present; and, the location with a top soft layer is unfavorable, particularly when the hard layer has a large location coefficient. The case study of Yanguan landslide illustrates that the location of stabilizing pile is determined with the proposed method is effective, with a considerable decrease in both the displacement and internal force of the stabilizing piles.