Study on the failure characteristics and reinforcement support of mining-induced main roadway in deep thick coal seam

Addressing the challenges of roadway failure and control under strong mining disturbance in deep thick coal seams, this study focuses on the West Rail Roadway at the -593 m level of the No.11 Mine, Pingdingshan Tianan Coal Mining Company Limited. Based on field measurements of roadway deformation and working face pressure, combined with rock mechanics analysis and numerical simulation, the failure characteristics of the roadway were investigated. Differential reinforcement measures were subsequently proposed and validated through engineering application. The results indicate that cyclic dynamic and static loading from the working face causes loading and unloading of deviatoric stress in the surrounding rock, leading to progressive damage and failure of the coal-rock mass. Due to the heterogeneity of the surrounding rock and the use of symmetrical support, significant deviatoric stress concentration occurs in the weak rock masses at the lower sidewall and shoulder of the roadway, resulting in instability at these critical locations and ultimately causing zonal, asymmetric failure. The core principle of the proposed reinforcement is to strengthen the broken rock zone at these critical points and enhance the energy absorption capacity of the support system. Field application shows that after reinforcement, the deviatoric stress relative gradient in the surrounding rock decreased by over 15%, the plastic zone in the coal roadway section was reduced by approximately 1 m, and the maximum roadway deformation decreased by about 55%.