Research On Pre-grouting Reinforcement And Roadway Support Technology Of Ground Directional Drilling In Fault Zone Roadway

In order to solve the problems of large-area deformation of the roadway in the east wing of Yuandian No.1 Mine in Huaibei when it passes through the geological structure belt,it has caused great difficulties in construction and support work.By means of numerical simulation and field measurement,based on the geological conditions of the east wing roadway and the layout of the original roadway,the fault structural belt is strengthened by ground directional drilling and pre-grouting,and a new roadway support scheme is designed.The technical parameters and the rationality of the plan for slurry reinforcement and roadway crossing fault geological structural belt support plan are systematically studied.The following conclusions can be drawn from the above research:(1)Determine the feasibility of the ground pre-grouting project according to the geological conditions of the east wing roadway,and determine the grouting hole layout as 1 group of ground directional drilling with three holes,and at the same time adopt the static pressure sub-sequential and segmental downward grouting The cement singleliquid slurry with a specific water-cement ratio is used to treat the three underground tunnels in sequence to ensure the steady progress of the grouting project.(2)The overall stratum of the directional drilling pre-grouting reinforcement project on the east wing road surface was simulated by the COMSOL simulation software.Research is carried out to analyze the temporal and spatial evolution law of grout diffusion in the ground pre-grouting project of East Wing Roadway.The results show that the grout takes the section of the grouting pipeline as the center,and diffuses from the inside to the outside.Under the action of grouting pressure and gravity,the grout spreads out along the grouting pipeline and finally reaches the front of the fault.When the grout encounters the fault,it seeps and consolidates at the fault,and finally forms a grouting curtain wall around the fault.(3)The Hawk-Brown strength criterion is used to calculate the failure mode and stress solution of the surrounding rock in the nonlinear roadway,and the surface displacement of the surrounding rock is calculated in combination with the lithological conditions of the east wing roadway.In addition,the length of the anchor rods and the row spacing between the anchor rods are determined,the U-shaped shed is analyzed according to the principle of the force method,and the dangerous section of the shed under the stress is pointed out.Finally,the improvement of the reinforcement and reinforcement of the anchor frame and the anchor cable beam and the grouting support form is proposed plan.(4)According to the geological data of the east wing roadway through the a F1 fault project,the overall deformation trend of the roadway is analyzed by simulating two support schemes,and the stress field,displacement field and plastic zone of the surrounding rock are studied.It is concluded that after adopting the improved scheme,there is an effective anchoring point in the deep part of the bolt and the anchor cable,and the displacement deformation,the peak value of stress change and the failure of the plastic zone are greatly improved compared with the original scheme.At the same time,the necessity of the high-strength support scheme is verified by the on-site damage industrial test of the surrounding rock of the roadway,so as to ensure the safety and stability of the east wing roadway through the fault zone project.Figure [64] Table [8] Reference [94]...