Analysis on the development characteristics and genetic mechanisms of the Weicheng Landslide along Wu-Chang Expressway

Abstract

[Objective] The large-scale accumulation landslide induced by loading and rainfall effects located in Weicheng Town, Guiyang City, Guizhou Province, China. The landslide poses a threat to the safe operation of the hydropower and water conservancy projects downstream of the Maotiao River. It is crucial to reveal the developmental characteristics and genetic mechanisms of the landslide under the coupling effect of loading and rainfall. [Methods] A combination of geological surveys, field monitoring, drilling and numerical simulations was employed. These method were used to elucidate the material composition and developmental characteristics of the landslide. Additionally, the displacement field, shear band characteristics, effective stress state of the slip zone, and slope stability under natural conditions, loading, and the combined effects of loading and rainfall are analyzed. The primary triggering factors and genetic mechanisms of the landslide were systematically summarized. [Results] The results show that the landslide is in a stable state under natural conditions and a marginally stable state under loading conditions. However, under the combined effects of loading and rainfall, it transitions to an unstable state, exhibiting signs of overall deformation. Under the combined effects of loading and rainfall, the displacement field progressively increases, shear band characteristics become more pronounced, and the effective stress in the slip zone initially increases but subsequently decreases, leading to a continuous reduction in stability. [Conclusion] The failure mode of the landslide under the coupling effect of loading and rainfall is characterized by backward pushing and forward traction. The topography, geomorphology, and lithology of the strata constitute the geological conditions for the development of the landslide. Rear-edge loading serves as the preparatory condition, while intense rainfall acts as the primary triggering factor for the landslide. Our findings provide guidance for the prevention and control design of Weicheng landslide along Wu-Chang Expressway and offer reference for the prevention and control of accumulation landslides induced by loading and rainfall effects.

Keywords

Wu-Chang Expressway / accumulation landslide / loading / rainfall / numerical simulation / genetic mechanism / shear band / stability