Influence analysis of irregular bedrock surface on failure characteristics of bedrock and overburden layer slope by material point method

Overburden landslide is a common natural disaster worldwide. Many scholars study the stability of the overburden layer based on a linear, fold-line, or circular bedrock surface. They rarely systematically analyze the influence of irregular bedrock surfaces on instability characteristics of the overburden layer, because quantitatively characterizing an irregular bedrock surface is still problematic. This paper proposes a new method of random reconstruction of a bedrock surface based on the inverse discrete Fourier transform. And combined with the material point method (MPM), the whole process of slope instability is simulated and analyzed. Then the influence of the irregular bedrock surfaces on the instability characteristics of overburden landslides is studied quantitatively. The results indicate that the bedrock surface has a significant influence on instability characteristics of overburden landslide. The effect of bedrock surfaces represented by Fourier descriptor D₁ shows duality, and that controlled by D₂ can promote the stability of the overburden layer, and that reconstructed by D₃ shows diversity. Furthermore, the influence laws of irregular bedrock surfaces on the instability characteristics of overburden landslides are proposed.