Abstract
In western mining areas, roadways excavated in weakly cemented thick coal seams often experience significant deformation and support failure due to poor roof conditions, low cementation strength, and stress redistribution. Taking the 11,703 transportation roadway of the Dananhu No. 7 Coal Mine in Xinjiang as a case study, this paper investigates the deformation mechanisms of the surrounding rock and proposes an optimized support technology. Using numerical simulations, theoretical analysis, and field monitoring, the study reveals that roof failure evolves through stress redistribution, plastic softening, interlayer separation, and fragmentation, ultimately forming a 3.5 m plastic failure zone. The existing support system fails to establish effective deep-shallow coordination, with shallow bolts yielding and deep cables underutilized. To address this, a Graded Anchor Composite Support Technology is proposed, consisting of surface concrete, shallow high pre-tensioned bolts, mid-depth short cables, and deep long cables. The optimized design enhances support performance and restricts plastic zone expansion. Field application and simulation results show a 73.3% reduction in roof subsidence and a 40% decrease in plastic zone depth. The study provides engineering guidance for roadway support in similar geological conditions.