Abstract:Aiming at the major technical challenge of stability control of highly stressed weak and fractured surrounding rock in deep mining, this study takes a lead-zinc mine roadway project with a burial depth of up to 1500m in Yunnan as the research object, and systematically reveals the failure mechanism of the surrounding rock of the deep-ground shafts and roadways by combining the on-site monitoring and numerical simulation in FLAC3D. The study confirms various typical damage modes, such as high geostress extrusion deformation, structural surface-controlled block instability, joint-fracture-dominated roof wedge fall, and soft rock continuous rheological deformation. Numerical simulation results show that the depth of the plastic zone of the roadway (0.86~2.85m) is significantly affected by the section size, ground stress level and stratigraphic properties, in which the angle between the direction of the maximum principal stress and the joint surface is the key factor to control the asymmetric deformation. In view of the long-term anchorage force attenuation problem caused by joint distribution and creep effect of pipe slit anchor in broken surrounding rock, the “graded cooperative support” technology system is proposed: “threaded steel resin anchor + reinforcing steel mesh + shotcrete” active support is adopted for the high stress hard rock section; the soft and weak broken section is supported by “threaded steel resin anchor + reinforcing steel mesh + shotcrete” active support; and the soft and weak broken section is supported by “threaded steel resin anchor + reinforcing steel mesh + shotcrete” active support. The weak and crushed section adopts the composite support of “pipe slit anchor + steel arch + anti-bottom arch”, supplemented by long anchor cable to strengthen the key structural surface. The dynamic design principle is innovatively proposed, emphasizing that the support parameters should be dynamically optimized by combining the real-time monitoring data with the surrounding rock response. The engineering practice verifies that this technology can effectively control the deformation of the surrounding rock, which provides the theoretical basis and key technology path for the safe exploitation of deep resources.