Crustal stress is a critical parameter utilized to analyze the stability of the tunnel in underground hard-rock mining sites. In order to analyze the distribution law of crustal stress and its influence on the stability of the deep tunnel in the Huanaote mining area, the in-situ stress field model of this area was constructed firstly by using the borehole stress relief method. Moreover, the numerical model is established based on three real engineering conditions: the excavation direction is parallel, vertical, and intersection to the measured maximum horizontal principal stress direction, respectively. Results show that, compared with the other two layout schemes, the stress of two side walls reaches peak at 27 MPa, when the excavation direction is intersected to the measured maximum horizontal principal stress direction, which indicates that the support and maintenance of two side walls should be strengthened to ensure the stability of the tunnel and the safety of personnel and equipment in real projects.

Taking the auxiliary shaft proposed by Ruihai Mining Co., Ltd. as the research object, in order to study the load law of shaft lining and ingate under high stress fluid solid coupling in deep bedrock and the influence of different permeability coefficient on the stability of shaft lining and ingate surrounding rock, Midas software was used for numerical simulation analysis, and the results show that:( 1) After the shaft excavation, the pore water pressure of surrounding rock around the shaft wall and ingate decreases gradually, which is the main permeable area. After the support, the pore water pressure is obviously raised, and the water isolation effect of the supporting layer is obvious. (2) After the shaft excavation, the area near the arc surface of shaft wall tangent to Y direction shows high compressive stress, and the maximum principal stress at - 1277.5m depth is more than 150MPa. When the polar angle increases from 0 to 180 °, the maximum principal stress increases first and then decreases. (3) After the excavation of ingate, the bottom corner and arch top are stress concentration areas before and after support. ( 4) Under the action of three different permeability coefficients, the influence of permeability coefficient on pore water pressure and maximum principal stress can be ignored after supporting measures are taken. The research results provide important theoretical basis for auxiliary shaft construction design.

Split-set bolt is widely used in supporting stope and roadway surrounding rock in metal mines. The maximum pull-out force generated by the relative slippage between the anchor bolt and the drill hole can serve as an indicator for assessing its anchoring force, and the anchoring force of the grouted anchor bolt exhibits certain regularity over time. This pull-out test was carried out at different time points after the construction of the split-set bolt by using the drawing equipment, and the variation law of its anchoring force with time was studied. The anchoring force on per unit area of surrounding rock is selected as a evaluation parameter, and the reinforcement support scheme of surrounding rock is optimized from the aspects of stress release of surrounding rock in the initial stage of excavation and stability of anchoring force on per unit area of surrounding rock. The convergence monitoring measurement method of roadway surrounding rock is adopted, and the same bolt drawing area is selected to verify the feasibility of the reinforcement support scheme. The effectiveness of the reinforcement scheme is verified by monitoring and comparing the roof subsidence and the lateral convergence of two walls between two different support schemes.

The construction of deep underground engineering is greatly influenced by complex geological conditions such as high stress, faults, and fracture zones, which significantly affects the stability of the project. Taking the construction of 1,915-m-deep shaft in Sanshandao Gold Mine as the engineering background, which passes through many different strata and multiple fracture zones, the stability evaluation and failure zone prediction during its excavation under the influence of high stress, uneven strata, and fault structure are studied. Results show that the range of the failure zone increases significantly when the shaft passes through the fracture zone or different lithologies, and the maximum depth is 5.28 m. When the distance between the rock mass in the borehole and the excavation face is greater than 48 m, the disturbance superposition effect basically disappears. This paper provides theoretical and data support for the design and construction of the kilometer-deep shaft in Sanshandao Gold Mine.