In view of the mining problems faced by Chalukou molybdenum-lead-zinc polymetallic mine in the Greater Khingan Mountains under deep (750-1 000 m), complex structure and volcanic rock geological conditions, the optimization of filling mining height based on rock mechanics and numerical simulation was carried out. Firstly, the mechanical parameters of the main rock mass in the mining area were obtained by rock mechanics tests, and a three-dimensional geomechanical model that accurately reflects the geological structure and topographic characteristics of the mining area was constructed using 3Dmine, ANSYS and Surfer software. Then, FLAC3D numerical simulation was used to systematically compare and analyze the influence of three mining heights of 60 m, 90 m and 120 m on the stability of stope and surface. The results show that the mining height of 60 m can effectively inhibit the expansion of plastic zone and control the displacement and stress concentration, which is the safe and economical optimal mining scheme. Although the mining height of 90 m can basically maintain the stability of the stope, there is a risk of local plastic zone penetration. The mining height of 120 m leads to the horizontal deformation, inclination and curvature of the surface far exceeding the safety limit. The research results clarify the safe mining height threshold of the complex deep orebody, revealing the internal mechanism of the increase of mining height leading to the penetration of plastic zone, which provide a theoretical reference for the optimization of deep filling mining scheme under similar complex geological conditions.

Polymetallic mine  /  Stope stability  /  Mining height  /  Mining scheme optimization  /  Numerical simulation