Dynamic mechanism triggering an underground-mining-induced landslide in karst mountains, Southwest China

Abstract  

The karst mountain region in Southwest China frequently experiences massive geo-disasters due to its geology and ongoing human engineering activities. As such, studies on the prevention and control of such disasters are urgently required. Using geological field surveys, a block discrete element method (UDEC) simulation, and related theoretical analysis, we further identified key features, contributing factors, and dynamic mechanism of an underground-mining-induced landslide that occurred at Pusa in western Guizhou Province. Our results show the following. First, leading factors influencing dynamic formation of this landslide include the microtopography with a lithology comprising a hard upper section and soft lower section, the slope structure, weathering, and triggering factors of the goaf left by shallow coal seam mining, the heavy rainfall, and the mine blasting vibrations. Furthermore, progressive deformation of the landslide showed notable subsidence and backward rotation, with the former being a common characteristic of underground-mining-induced landslides. Finally, once the mine blasting vibrations triggered the critical collapse that led to the landslide, the subsequent dynamic responses involved the following four stages: collision and fragmentation, scraping the bedrock, debris flow, accumulation and stabilization. Based on these conclusions, we systematically identified the dynamic mechanism that led to the formation of the landslide by referring to a proposed mechanical conceptual model of the entire landslide evolution.