Characteristics and mechanism of landslides on highway landfill along Xiaolangdi Reservoir of the Yellow River:A case study

On February 17, 2023, a landslide occurred on a highway slope located on the bank of Xiaolangdi Reservoir of the Yellow River, with a volume of about 1,200 m 3 , which directly led to the interruption of the road and had a serious social impact. In this paper, the area where the landslide was located was studied and analyzed by means of field investigation, remote sensing images, laboratory tests and numerical simulation. The evolution pattern of landslide groups under the influence of human engineering activities is traced, and the disaster-causing mechanism of landslides is investigated in terms of climatic factors, water level changes, stress changes, and the nature of the fill. The results indicate that: (1) Water level changes can lead to a decrease in the stability coefficient of ancient landslides, but have no direct effect on the occurrence of landslides. The change of soil stress caused by artificial excavation will change the distribution of soil plastic region, which makes the potential sliding surface changing; (2) Rainfall and temperature are the key elements affecting the fill-type landslides, and the alternating period between winter and spring is the high susceptibility period of landslides; (3) Sandstone stratigraphy undergoes significant expansion and deformation under freeze-thaw action, so additional monitoring of bedrock deformation can be considered when monitoring fill-bedrock slopes.