Coal Rib Instability and Differential Control in Steeply Inclined Working Faces with Coal Seam Partings

Coal rib instability is a critical challenge in steeply inclined, large-mining-height longwall faces containing coal seam partings. Taking the No. 4103 working face of Changcheng No. 1 Coal Mine as an engineering case, this study integrates theoretical analysis, numerical simulation, and field verification to investigate the underlying failure mechanisms. A segmented shear–slip mechanical model is developed using limit-equilibrium analysis to derive the stability margin, through which the coupled effects of seam dip, mining height, and parting properties on rib stability are quantified. Three-dimensional distinct-element simulations further reveal that rib deformation follows a consistent spatial pattern—middle section > upper section > lower section—and that the position and number of partings modify the load-transfer path and failure-surface continuity. Based on these findings, a coordinated control strategy is implemented, incorporating zoned differential support, dynamic adjustment of mining parameters, and localized reinforcement. Field application substantially reduces the frequency and depth of rib spalling and improves support stability and production continuity. The results provide a practical basis for coal rib control under comparable steeply inclined, large-mining-height conditions.