Explore the Impact of Coal Mining on the Safety of the Upper Reservoir Based on FLAC3D

With the increasing scarcity of land resources, the rational utilization of coal mine goaf areas has become particularly important. To study the impact of coal mining on the safety of the upper reservoir and dam, numerical simulation software FLAC3D was used to model existing and future goaf areas created by coal mining. By analyzing the maximum and minimum principal stress clouds, vertical displacement clouds, and the distribution of surface plastic zones for two selected profiles, it was found that under current conditions, coal mining causes a maximum surface subsidence of nearly 2.0m, with the dam area located at the edge of the subsidence basin. The southern area is closest to the goaf, with a maximum subsidence of about 0.5m, and obvious tensile and shear plastic zones are produced; in the future, after the planned mining workface is completed, the reservoir dam area will experience cumulative subsidence of 2800mm, tilt of 5mm/m, curvature of 5×10^-3/m, horizontal movement of 800mm, and horizontal deformation of 6mm/m, which could potentially cause severe deformation and damage to the reservoir dam.