急斜煤层初次破断后基本顶稳定性分析

针对急斜煤层水平分段综放开采的特点，将沿倾向初次破断后的基本顶视为三边固支一边自由，受纵横载荷共同作用的斜置矩形板力学模型.应用Kirchhoff薄板理论，考虑中面内力对弯曲的影响，运用能量法得到了顶板挠度的解析表达式.探讨了基本顶的挠曲变形特征，分析了煤层倾角、水平分段高度和基本顶厚度对挠曲变形的影响.研究发现：在急斜煤层岩层控制中，煤层倾角存在介于55~65°之间的临界区域，据此可推断在上覆岩层中是否存在“上三带”（危险性离层带）；通过选取合理的水平分段高度，尽可能满足生产的需求，又可有效地控制顶板的变形；顶板厚度大于4 m可作为急斜煤层关键层的几何特征.结合新疆六道湾煤矿的具体开采情况，验证了模型和结论的合理性.

Stability analysis of basic roof after first destruction in the steep seam

To the character of horizontal section top coal sublevel caving in the mining steep seam,the basic roof after first destruction along sloped direction was regarded as mechanical model of inclined rectangle board subjected to forces acting vertically and horizontally with fixed ends on three edges and free end on one edge.Based on the theory of board and energy method,the analytical solution of deflection was given considering the influence of inner force in central surface on the bend of the roof.The deflec...