Supporting optimization of thick seam roadway with top coal based on orthogonal matrix analysis

Aiming at the problem of large deformation and difficulty in surrounding rock control of the top coal roadway in thick seam, theoretical analysis, theoretical analysis, numerical simulation, orthogonal matrix analysis and other methods were used to study the roof deformation and support parameter optimization of the top coal roadway in thick seam. Firstly, the structural model and roof mechanical model of the top coal roadway in thick seam were established, and the deformation coefficient T_K was defined based on the relationship between curvature radius and bending moment, maximum bending moment and ultimate tensile strength of beam. According to the ratio of deformation rate between T_K and beam to determine the roof deformation mode of top coal roadway, the discriminant conditions of roadway roof stability under two deformation conditions are obtained. Due to the characteristics of serious coal-rock fragmentation, large roof deformation, and integration of top coal and side coal. Therefore, the combined support method of "high prestressed long and short anchor cables" is proposed by double arch bearing structure control technology. Finally, based on the orthogonal matrix analysis method of supporting parameters optimization of the top coal roadway in thick seam, the analysis amount of supporting scheme is significantly reduced, the comprehensive evaluation of multi-factor and multi-supporting effect of roadway support is realized, and the optimal supporting scheme is obtained. Compared with the surrounding rock of the roadway without support, the deformation of the roof is reduced by 27.27%, the deformation of the two sides is reduced by 45.24%, and the tensile failure volume is reduced by 54.66%. The top coal roadway in thick seam has been effectively controlled, which provides guarantee for high yield and high efficiency of the mine.