The failure pattern and transfer features of the 2020 Qingliucun landslide

The 2020 December 5^th Qingliucun landslide in western China presents a high locality and complex movement features. Its landslide source sits at the margin of a platform of a hillslope, which suffers from repeated earthquake and snow-water infiltration. The data from Insar and monitoring devices reveal that this landslide body have deform for 6 years and present a stepped three-phase failure process. The PFC simulation is also used to reproduce the failure process and motion features. It is found that several earthquakes result in the initiation of this landslide body and the snow-water infiltration plays a direct role in triggering this landslide by weakening the strength of soils. The landslide body scrape the slope mass during its transfer and block the river near the toe of the hillslope. The huge energy of landslide body is consumed during this process as verified by PFC simulation. The results can offer a good guidance to the hazard mitigation of this kind of landslide.