Research on critical disturbance depth and stability of goaf under vertical ground load

The mined-out area left after the mining of mineral resources achieves a new balance through stress redistribution, and forms a stress arch to carry the weight of the overlying rock.When construction is carried out on the surface of the goaf, the increase of the vertical load on the ground may destroy the stress balance of the goaf, induce the “activation” of the goaf, and cause safety hazards.In order to analyze the suitability of the mining area's surface development and utilization, this paper adopts the additional stress method and the numerical analysis method to study the critical disturbance depth and stability of the goaf under the vertical load of the goaf ground.The results show that when the vertical load influence depth is in contact with the goaf collapse and the top interface of the fracture zone, it is just in a critical stable state.Combining the actual situation of the mining area, the critical disturbance depth of the mining area when the load is calculated is 31.38 m, and the FLAC^3D software is used.The stability of the mined-out area under the simulated critical state load (240 kPa) provides the necessary basis for the prevention and control of ground disasters and land development and utilization in the mining area.