Abstract: The karst sinkholes induced by pumping results from several changes in water levels, with each fluctuation reducing the strength of the overburden soil, similar to that of the fatigue effect. Consequently, the influence of fatigue is articulated by delineating the strength attenuation function of the covering soil layer; the water level fluctuation condition is conceptualized as the air pressure fluctuation, and the basic air pressure fluctuation function corresponding to the water level variation is established. The COMSOL solid mechanics and laminar flow modules are utilized in response to the collapse of Yanyu Village in Zhenfeng County, Guizhou Province. The numerical modeling of the fluid-solid coupling in the formation of the soil cavities due to the karst sinkhole induced by the pumping is conducted. The findings indicate that: 1. No plastic zone exists directly above the soil cavity; 2. The orientation of the plastic zone’s development transitions from the failure angle to a vertical alignment; 3. An annular plastic zone manifests on the surface, potentially contributing to the formation of the collapse annular crack; 4. Displacement increases as proximity to the soil hole diminishes.

Key words: Karst Sinkholes, COMSOL, Water Level Fluctuation, Fluid-Solid Coupling, Fatigue Effect