Characteristics of deep ground stress and surrounding rock mining damage effect in Maoping lead-zinc mine, Northeastern Yunnan, China

Deep mining under high in-situ stress and intense mining-induced disturbance can trigger severe surrounding-rock damage and dynamic disasters, particularly under complex geological conditions. This study investigates the deep stress distribution and mining-induced damage mechanisms of the Maoping lead-zinc mine in northeastern Yunnan Province, China Hydraulic fracturing stress measurement, numerical simulation, and field investigation were adopted to analyze the distribution characteristics of the deep stress in the mining area and the damage characteristics of the surrounding rock during deep mining. The maximum horizontal principal stress σ_hmax, minimum horizontal principal stress σ_hmin, and vertical stress σ_v of the Maoping lead-zinc mine at depths ranging from 737 m to 1 517 m are 22.24 MPa to 48.48 MPa, 13.79 MPa to 37.01 MPa, and 18.77 MPa to 41.93 MPa, respectively. The azimuth of the maximum principal stress direction θ ranges from 297.4° to 309.1°. In addition, the deep core obtained from drilling is accompanied by the phenomenon of pancake formation, indicating that the study area has strong horizontal tectonic stress. The range of surrounding rock plastic damage caused by mining is 25～36 m at an elevation of 300～0 m in the eastern mining area of the Maoping lead-zinc mine, and 15～27 m at an elevation of 600～300 m in the western mining area. The range of plastic damage caused by mining increases linearly with depth and is mainly characterized by shear and tensile failure. Based on the deformation and failure characteristics of the Maoping lead-zinc mine roadway, it is divided into three main categories and eight subcategories: stress control type, rock structure control type, and stress-structure composite control type. Furthermore, 16 typical failure modes are proposed, and their occurrence conditions and failure mechanisms are analyzed. This study provides a scientific basis for dynamic disaster prevention, surrounding rock control, and reservation of waterproof rock columns in the deep mining of lead-zinc deposits in northeastern Yunnan Province, China.