Search

On January 27, 2021, a small-scale loess landslide occurred in Dangchuan Village, Yongjing County, Gansu Province, China. Timely monitoring and warning helped to prevent any casualties. The sliding mass of the Dangchuan landslide fell in two stages with an interval of 24 s and lasted for a total of 31 s. Eventually, the Dangchuan landslide had a descent height of approximately 120 m and a sliding portion stretching approximately 350 m. The landslide volume was approximately 3 × 104 m3. Based on the investigation of different stages of the Dangchuan landslide and the characteristics of the deposition area, the induction of this landslide was attributed to the effect of frozen stagnant water. Following field investigation of the landslide source and crack areas, a potential sliding mass model with a volume of 5 × 104 m3 was obtained via calculation. To predict the disaster scope of potential landslides, we first used DAN3D software to invert this Dangchuan landslide. Then, based on the numerical model parameters obtained from the inversion, the sliding accumulation process of the potential slide mass was simulated. The results showed that the maximum disaster scope of the potential slide mass would be larger than that of the Dangchuan landslide. The new deposit would cover an area of approximately 3.5 × 104 m2, with a thickness in the range of 0–6 m. The new deposition area would expand by approximately 50 m in the long-axis direction compared to the Dangchuan landslide, impacting the houses and roads. The DAN3D prediction results of the disaster scope will help residents in the potential danger zone evacuate in advance, reducing unnecessary damage. [ABSTRACT FROM AUTHOR]

A catastrophic loess flow slide was triggered by the 2013 Minxian–Zhangxian earthquake in Yongguang village, Minxian County, Gansu Province, China. The landslide destroyed eight houses and killed 12 persons. The landslide involved the failure of 14.0 × 104 m3 of loess deposits from the source area. The displaced materials traveled 1000 m with an elevation descent of 180 m, covering an area of 4.2 × 104 m2. A numerical model (DAN3D) is used to simulate the post-failure behavior of the landslide based on a detailed field investigation. A combination of the frictional model and Voellmy model provides the best performance in simulating the landslide using trial and error. The simulation results indicate that the landslide lasted approximately 120 s and had an average velocity of 8.3 m/s. The final runout distance and deposit distribution are in a good agreement with the actual situation, indicating the accuracy of the simulated results. Therefore, it is expected that the models and parameters could improve the precision of hazard zonation for areas with geological, topographical, and climatic features similar to the Yongguang landslide area. [ABSTRACT FROM AUTHOR]