Influence of near-fault roadway stability based on numerical simulation method

During the coal mining process, the stability of roadway surrounding rock is affected by various geological factors, among which the influence of fault structures on roadway deformation and failure is particularly critical. Taking the 4326 working face of Sanyuan Coal Mine as the engineering background, we use the FLAC^3D numerical simulation software to simulate the deformation and failure of working face roadways in fault-proximity areas and fault-free areas under mining influence, and study the deformation and failure laws of surrounding rock after roadway excavation and support. The research results show that: the fault disturbance causes vertical stress in the adjacent area at a burial depth of 340 m to rise to 8.9~9.2 MPa, which is 4.7%~8.2% higher than that in the fault-free area. The asymmetric stress field leads to differences in surrounding rock deformation; the deformation of roadway surrounding rock in the near-fault area is greater than that in the fault-free area. After the driving face exceeds the section by 14 m, the vertical displacement of the roof and floor in the near-fault area is 111.6 mm, 58.8% higher than that in the fault-free area; the horizontal displacements of the two sides are 100.4 mm on the coal pillar side and 55.6 mm on the solid side, increasing by 79.3% and 75.4%, respectively. Faults aggravate the deformation of roadway surrounding rock, and the increase in horizontal displacement is more significant; faults also lead to the expansion of the plastic zone depth of roadway surrounding rock. Compared with the fault-free area, the failure depths of the plastic zone in the floor, coal pillar side and solid side are expanded by 50%, 40% and 33.3% respectively. Faults mainly affect the expansion of the plastic zone in the floor and two sides, and the failure depth of the roof is less affected.