Process analysis of causes of Luanshigang landslide in the Dadu River, China

Abstract

Large-scale landslides along rivers that incised valleys in the mountain region have been widely concerned. Occurrences of landslides along rivers are closely linked with river valley evolution. Field investigations and numerical approaches were employed to examine the landslide formation mechanism and analyze the relationship between landslide and river valley slope evolution. The formation mechanism of the multi-level landslide is investigated. The results indicate that gentle weak structural planes parallel to the slope were the geological origins of the landslide. The causes of the landslide are regional tectonics, river valley cutting, and water infiltration. River valley cutting causes the unloading of the weak bedding structure of the slopes, which pulls the intermediate strata out like a drawer. The interbedded weak interlayer is a determinant factor for formation of the landslide, and engineering excavation and continuous rainfall further induced the landslide.