煤-岩层倾角对沿空留巷非对称变形破坏的影响研究

Study on the Influence of Coal-Rock Seam Dip Angle on the Asymmetric Deformation and Failure of the Gob-Side Entry Retaining

为揭示煤层倾角对沿空留巷变形破坏的影响,以山东锦丘煤矿为工程背景,通过现场调查、力学模型分析和数值模拟研究了缓倾煤层沿空留巷非对称变形破坏的倾角效应。结果表明:缓倾煤-岩层沿空留巷两帮变形呈现显著非对称特征,随着倾角增大,非对称变形特征加剧,煤-岩层面变形阶跃效应显著;煤-岩层倾角大于10°时,窄煤柱煤-岩界面已具备发生剪切滑移变形的条件;巷道两帮围岩沿煤-岩界面滑移和非对称变形、破坏特征加剧的本质是煤-岩层倾斜导致自重应力和窄煤柱附加应力沿层面分量增大。研究结果可为缓倾斜煤层开采和支护提供参考。

In order to reveal the influence of coal seam dip angle on the deformation and failure of the gob-side entry retaining,taking Jinqiu Coal Mine in Shandong Province as the engineering background,the dip angle effect of asymmetric deformation and failure of the gob-side entry retaining in gently inclined coal seam was studied by field investigation,mechanical model analysis and numerical simulation.The results show that the deformation of the two sides of the gob-side entry retaining in gently inclined coal-rock seam shows significant asymmetric characteristics.With the increase of dip angle,the asymmetric deformation characteristics are aggravated,and the step effect of the coal-rock seam surface deformation is significant.When the dip angle of coal-rock is greater than 10°,the coal-rock interface of narrow coal pillar has the condition of shear slip deformation.The essence of the slip and asymmetric deformation along the coal-rock interface and the aggravation of the failure characteristics of the surrounding rock on both sides of the roadway is that the tilt of the coal-rock seam leads to the increase of the gravity stress and the additional stress of the narrow coal pillar along the plane.The research results can provide reference for the mining and support of gently inclined coal-rock seam.