关键词:

煤岩组合锚固体 , 拉拔试验 , 锚固性能 , 声发射

Abstract: The geological conditions of coal-rock roadways are complex, and the anchoring performance of bolts across layers is constrained by multiple factors, leading to suboptimal support effectiveness. This study focuses on the key influencing factors of bolt anchoring performance in coal-rock roadway support. Firstly, the physical and mechanical parameters of different coal seams and roof-floor strata in typical mines were obtained, combined with the hollow inclusion stress relief method to measure in-situ stress distribution within the roadway. Based on field data, a numerical model was established to invert the stress state of the bolt working environment during excavation and mining, determining a confining pressure range of 0–15 MPa. Through laboratory tests, the influence patterns of different coal-rock strength ratios (1:2, 1:3, 1:4, 1:5), confining pressures (0, 5, 10, 15 MPa), and cross-layer anchoring methods (coal-to-rock, rock-to-coal) on the load-bearing performance of coal-rock composite anchorages were systematically analysed. The results indicate that: Increasing the coal-rock strength ratio significantly enhances the ultimate pull-out load of bolts (from 45.4 kN at 1:2 to 68.79 kN at 1:5); Higher confining pressure effectively improves anchorage stability (ultimate load increases from 34.52 kN at 0 MPa to 77.55 kN at 15 MPa); The coal-to-rock anchoring method demonstrates superior performance compared to rock-to-coal, exhibiting delayed interface debonding and higher residual strength. These findings provide theoretical and experimental support for bolt support design in coal-rock roadways under complex geological conditions.