Simulating the Xinmo landslide runout considering entrainment effect

Abstract

This paper investigates the setting, causes, and main dynamic characteristics of the landslide that occurred at Xinmo village, Diexi, Sichuan province, China, on June 24, 2017. By comparing the pre- and post-sliding DEMs, the landslide involved the failure of ≈ 3.0 × 106 m3 rock mass from its source area, and had a final volume of ≈ 6.3 × 106 m3. The landslide runout extended 2800 m horizontally and 1200 m vertically, and covered an area of ≈ 143.1 × 104 m2. Field investigation indicates that entrainment was one of the major causes of the increase in volume of landslide. To reproduce the behavior of the landslide runout, a depth-averaged continuum model that takes entrainment into consideration is applied. The simulated results generally agree well with the characteristics of the sliding path and distribution of the landslide deposit as observed in the field. It is demonstrated that entrainment plays a significant role in landslide mobility and volume. The final volume of the landslide is calculated about 6.21 × 106 m3, which has more than double its initial volume.