Research on the effect of high pre tension anchor rod and cable combined support in strong structural stress tunnels

This paper is based on the strong structural stress tunnels of Luxin No.2 Mine in Xinjiang, and focuses on the stability of the surrounding rock of E4205 lower groove roadway. The application effect of high pre tension anchor rod and cable combined support technology is deeply studied. Firstly, the maximum horizontal principal stress is measured through hydraulic fracturing stress testing σ_H is 13.33 MPa, minimum horizontal principal stress σ_h is 7.05 MPa, vertical principal stress σ_v is 7.62 MPa, and the maximum horizontal principal stress direction is 47.0° northwest. Secondly, FLAC^3D numerical simulation is used to study the influence of anchor rods on the stress distribution of tunnel surrounding rock under two different levels of pre tension. It is revealed that high pre tension anchor rod support produces larger stress values and forms a wider range of effective compressive stress zones. Finally, a “high pre tension anchor rod and cable combined support” method is proposed for tunnels with strong structural stress. Through monitoring and comparative analysis of the deformation of the surrounding rock of the tunnel before and after the application of high pre tension anchor rod and cable combined support technology, it is found that the high pre tension anchor rod and cable combined support method can effectively control the deformation of this type of tunnel and ensure the safe production of the working face.