Abstract:
Regarding the problem of difficult support for deep high-stress soft rock in the 1201 air-return roadway of Jinneng Coal Mine, through on-site investigation, theoretical analysis, numerical simulation and on-site industrial tests, the deformation and failure mechanism of the surrounding rock of the roadway is systematically analyzed, and an effective support scheme is proposed. Firstly, the main mechanisms of deformation and failure of the surrounding rock of the roadway are studied and analyzed, and it is pointed out that poor geological conditions, surrounding rock seepage, and unreasonable support parameters are the main factors causing deformation and instability of the roadway. Based on the above deformation characteristics, an “anchor bolt (cable) + steel pipe shed + grouting + steel wire mesh” combined support scheme is proposed. This scheme achieves effective support of deep and shallow surrounding rocks through the organic combination of long and short anchor bolts, improving the overall stability of the surrounding rock. In terms of theoretical analysis, based on the Mohr-Coulomb criterion, the supporting force and the strength changes of the surrounding rock of the original support scheme and the optimized support scheme are compared, and the applicability of the optimized support scheme is verified theoretically. Numerical simulations revealed superior performance of the optimized solution across key parameters: roof support stress increased by 0.02 MPa, two-side support stress by 0.08 MPa, with horizontal and vertical displacements reduced by 125 mm and 137 mm respectively. Field trials confirm a 59.20% improvement in roof-to-floor convergence control and 62.42% enhancement in two-side convergence management compared to conventional methods. The refined support system effectively addresses deformation control in deep fractured soft rock roadways while providing critical insights for similar geological conditions.