Study on characteristics and genesis of high-localition loess landslide

Abstract

High-localition loess landslide has the characteristics of high potential energy, suddenness, concealment, rapid sliding speed, wide threat range, and strong destructive impact capacity. The main forms of damage are destruction and burial, making them a difficult problem for disaster prevention, reduction, and engineering governance in loess areas. Different landform types, stratum lithology, hydrogeological conditions and tectonics have essential differences in landslide formation. Based on typical examples of high-altitude loess landslides in Renda Town, Jingning County, Pingliang City and Dagou, Maiji District, Tianshui City, a systematic study was conducted through technical means such as engineering geological mapping, engineering geological exploration, and high-precision drone aerial surveys from the aspects of spatial distribution, landslide characteristics, causes, motion mechanisms, and disaster characteristics. The results showed that according to the classification of terrain and topography, high-localition loess landslide can be divided into slope type and valley type. Among them, the landslide in Renda Town, Jingning County, Pingliang City belongs to the slope type, moving in the form of “soil waves” , with the same periodicity and continuity as the landslide initiation in terms of movement time. The movement speed is rapid, and the movement sequence is as follows: the sliding body separates from the parent body, the soil slides, and the soil accumulates. The Dagou in Maiji District, Tianshui City belongs to a valley type and moves in the form of mud flow. The sliding of landslides and the initiation of accumulation bodies have a certain lag in time, and the speed is relatively slow compared to the former. The movement sequence is as follows: the sliding body separates from the parent body → soil accumulation → soil sliding → sedimentation, and its movement and accumulation characteristics are basically similar to those of viscous debris flows.

Keywords

• high-localition
• loess landslide
• accumulation body
• slope surface
• gully
• mudflow