Stability analysis and optimization design of roadway surrounding rock under multiple factors

To address the issue of severe mine pressure manifestations and difficult-to-control deformation in deep coal seam roadways, an orthogonal numerical simulation experiment was conducted based on the Kastner formula.This experiment examined five factors affecting the stability of roadway surrounding rock: height-to-width ratio, lateral pressure coefficient, depth, cross-sectional shape, and surrounding rock strength.Sensitivity of each factor to roadway deformation and damage was studied using variance analysis and intuitive analysis charts.The stress distribution patterns of elliptical and rectangular roadways under different lateral pressure coefficients and height-to-width ratios were analyzed using the plane elasticity complex variable function theory.Optimal designs for the height-to-width ratio and shape of elliptical and rectangular roadways were developed.The results showed that the main factors affecting the stability of surrounding rock are the strength of the surrounding rock and the lateral pressure coefficient, while depth, cross-sectional shape, and height-to-width ratio are secondary factors.Elliptical roadways exhibit the smallest difference in surrounding rock stress under isotropic stress ratios.Rectangular roadways have lower stress concentration when the width is 5 m and the height-to-width ratio is approximately 0.6.For areas with rapid stress increase in rectangular roadways, an optimized rounded rectangular roadway was designed considering bearing characteristics and cross-sectional utilization, and a calculation formula for the corner radius was established.The optimization performance of this design was verified through numerical simulation.