关键词: 近距煤层, 应力分布规律, 围岩破坏机理, 巷道稳定性控制

Abstract: During the downward mining process of close-distance coal seam，affected by the upper coal goaf and pillar, complex changes have occurred in the stress environment and the failure mechanism of the roadway surrounding rock in the lower coal. The stress distribution law, the deformation failure mechanism and stability control of the roadway group in the lower coal were researched through the comprehensive methods of theoretical analysis, numerical simulation and engineering application. The research has shown that：1) The pressure relief effect of overlying goaf led to low stress concentration degree of roadway under goaf and more stable surrounding rock；2) Affected by the pressure transfer of coal pillar, the vertical stress was on a sharp rise with the stress concentration factor reaching 3.84, and large compression-shear failure appeared in two sides and shoulders of the roadway, which eventually led to the whole failure; 3) Roadway in the high stress zone under the coal pillar should adopt the arched section to increase the supporting strength and the anchor prestress; and the cables (bolts) layout in the roadway shoulders to make the supporting system couple with the plastic zone of surrounding rock and both get strengthened. With the optimized support, the roadway roof subsidence is reduced by 42.8%, the actual measured working load of the bolts and cables is reasonably distributed, which realizes the safe and effective control of the roadway of close distance coal seam under coal pillar.

Key words: 近距煤层, 应力分布规律, 围岩破坏机理, 巷道稳定性控制