考虑顶板赋存变化的近距离采空区下巷道变形机理及控制

Deformation mechanism and control of roadway under close-range goaf considering changes in roof occurrence

针对近距离采空区下巷道围岩变形严重问题,以钱家营矿2097W工作面为背景,采用数值模拟阐明了顶板赋存变化下巷道矿压显现特征。结果表明:顶板下沉量与直接顶泥岩的厚度呈正相关,与直接顶岩石强度呈负相关,随着直接顶泥岩厚度变薄顶板受剪切与拉伸破坏交替影响,顶板稳定性随直接顶强度减弱而降低,应力扰动下岩体内部裂隙向上扩展,于层间弱面处产生分区破坏,塑性圈范围增大,整体破坏模式复杂;进一步提出采用高预紧厚层锚固技术维控顶板,构建低损伤、小变形的稳态锚固岩梁,设计支护参数并开展了工业性试验,矿压监测结果表明巷道控制效果良好。

In response to the serious deformation of the surrounding rock of the roadway under close-range goaf,the No.2097W working face of Qianjiaying Coal Mine was taken as the background,and the numerical simulation was used to elucidate the characteristics of the roadway pressure manifestation under the change of roof occurrence.The results show that the subsidence of the roof is positively correlated with the thickness of the direct roof mudstone,and negatively correlated with the strength of the direct roof rock.As the thickness of the direct roof mudstone becomes thinner,the roof is alternately affected by shear and tensile failure,and the stability of the roof decreases with the weakening of the direct roof strength.Under stress disturbance,internal cracks in the rock mass expand upwards,and zoning failure occurs at weak interlayer surfaces.The plastic circle range increases,and the overall failure mode is complex;furthermore,it is proposed to use high pre-tensioning thick layer anchoring technology to maintain and control the roof,construct a low-damage and small deformation steady-state anchoring rock beam,design support parameters,and conduct industrial experiments.The results of mine pressure monitoring show that the roadway control effect is good.