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 along the Xiaolangdi Reservoir of the Yellow River, involving approximately 1,200 m3. This event directly resulted in road interruption and had profound social repercussions. This paper researches the landslide using a combination of field investigation, remote sensing imagery, laboratory tests, and numerical simulation. It traces the evolution of landslide occurrences influenced by human engineering activities and investigates the mechanisms by considering climatic factors, water levels fluctuations, and stress changes. The results indicate that: (1) fluctuations in water levels can reduce the stability coefficient of ancient landslides, albeit without directly triggering them. Moreover, alterations in soil stress induced by artificial excavation changes the distribution of the slope plastic zone, consequently altering potential sliding zones. (2) rainfall and temperature emerge as primary factors influencing the occurrence of accumulation landslides, it is particularly susceptible with the transition between winter and spring. (3) freeze-thaw action exerts significant pressure on sandstone bedding, which causes notable expansion deformation. Consequently, it is advisable to consider soil temperature and bedrock deformation when monitoring similar slopes.