Mechanism analysis of bedrock landslides in coal measures of Guangdong Province: a case study of the Lishui Wentouling landslide, Foshan City

The Lishui Wentouling landslide, Foshan City was investigated through investigation, drilling, and monitoring methods. The geological environmental conditions and disaster characteristics of the landslide area were identified, and the influencing factors and sliding mechanism were analyzed. The results show that: (1) the overall trend is that the larger the rainfall, the faster the sliding, with a sliding rainfall value of about 30 mm; (2) The development of coal bearing strata, along slope and fold structures are inherent factors in the formation of landslides. The excavation and long-term infiltration of rainwater into the coarse sandstone belt, resulting in static water pressure, are indirect triggering factors for landslide formation. Heavy rainfall is the direct triggering factor for landslide formation; (3) The sliding mechanism mode is characterized by early infiltration of rainwater and accelerated formation of sliding surfaces along the interface of carbonaceous mudstone due to softening of runoff. In the middle stage, excavation at the foot of the slope, combined with the gravity of the rock and soil mass on the slope and the static water pressure at the foot of the slope, acts downwards to penetrate the sliding surface. In the later stage, heavy rainfall induces landslides. This research can provide reference for the investigation, evaluation, monitoring, early warning, and subsequent prevention and control of landslides in similar coal bearing strata.