Abstract:
In view of the problems of large support difficulty and low excavation efficiency in fault zones, taking the 5-305 working face as the engineering background, through theoretical analysis coupled with FLAC
3D numerical simulation, the surrounding rock stress and deformation characteristics in the fault zone are systematically explored, the influence range of faults on the roadway surrounding rock as 30 m in front and behind is determined, providing a basis for zoning support. Based on the stress difference between the upper and lower plates of faults, a dynamic adjustment strategy for anchor cable row spacing of "upper plate densification and lower plate optimization" is innovatively adopted (1600 mm for the upper plate and 1200 mm for the lower plate); A technical scheme of "staged support+cyclic step distance zoning optimization" is proposed, which achieves parallel excavation and support operations in normal areas with a cyclic step distance of 2.4 m, and controls and stabilizes the surrounding rock in the fault zone with a cyclic step distance of 1.6 m. The on-site testing results show that the maximum displacement value of the roof and floor in the normal area is 72 mm, and the maximum displacement value of the roof and floor in the fault area is 108 mm; The excavation speed is improved from 7.2 m/d to 8.6 m/d, with an increase of 19.4%, significantly improving the coordinated efficiency of excavation and support. The research results provide a precise and efficient technical paradigm for rapid excavation and support of coal roadways under the influence of fault structures, which has significant promotion and application value for similar mines.