急斜煤层初次破断后基本顶稳定性分析  

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

作　　者：张嘉凡[1] 石平五[2] 张慧梅[1] 

机构地区：[1]西安科技大学力学系,陕西西安710054 [2]西安科技大学能源学院,陕西西安710054

出　　处：《煤炭学报》2009年第9期1160-1164,共5页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(50274058);2005年高等学校博士点专项基金资助项目(20040704002)

摘　　要：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项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4m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．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 deflected deformation character was investigated, and the influence of coal seam angle, horizontal section altitude and thickness of basic roof on deflected deformation was analyzed. The results show that there is a critical region between 55° and 65° for coal seam angle, which can be used to determine the presence of ＂three bands＂ （the dangerous separated strata zone） in the overlying strata; the yield requirements can be as much as possible to meet and basic roof deformation can be controlled effectively by selecting reasonable horizontal section altitude ; basic roof thickness t 〉 4 m can be regarded as geometrical properties of the key strata in the mining steep seem. The mining state in Liudaowan Coal Mine can verify the correctness of the theoretical model and conclusions.

关 键 词：急斜煤层 初次破断 基本顶 稳定性 

分 类 号：TD823.213[矿业工程—煤矿开采]