Failure mechanisms and characteristics of the Zhongbao landslide at Liujing Village, Wulong, China

Abstract

This article describes the Zhongbao landslide that occurred in Liujing Village, Tudi Township, Wulong District, Chongqing, China, on July 25, 2020. Due to the catastrophic soil and rock landslide, the houses and village roads of three villagers in the landslide area are damaged and formed weirs. The landslide eventually formed a barrier lake. In order to reveal the failure mechanism of the landslide, aerial data was collected on the landslide site using UAV and high-resolution remote sensing images. The characteristics of the landslide are analyzed based on the geological conditions and the properties of the rock formations in the landslide area. The continuous intense rainfall increased the water content of the landslide in this area, increasing its weight. Increasing the water content softens the sliding surface and lowers strength. Therefore, the rock and soil mass on the upper slope slides along the sliding surface under the action of gravity, causing a shale rock mass of about 1.3 million cubic meters to slide quickly from the upper part of the slope into the V-shaped valley and form a barrier dam and barrier lake. By evaluating the rising height of the initial dammed lake, the affected area can be predicted. Through the analysis of the study area, it can provide references for the failure mechanism of landslides, the characteristics of landslide bounce, and the risk assessment of cofferdams in Southwest China.