【作者】 王旭锋；

【导师】 张东升；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2009， 博士

【摘要】 我国西北矿区冲沟纵横交错的地形地貌特征,导致起伏变化的地表与浅埋煤层的开采相互影响更为显敏感和强烈,尤其是地表产状多样的冲沟坡体,使井下工作面矿压显现规律呈现出新的特征,对矿井安全高效生产造成不利影响。本文以基岩型和沙土质型采动坡体为研究对象,以工作面背沟推进为主要开采方式,综合运用实验室物理模拟、计算机数值计算、理论分析及现场实测等手段,对冲沟发育矿区浅埋煤层采动坡体活动机理及其控制进行了系统地分析,并初步指导了工程实践。主要研究成果如下:(1)首次揭示并证实了工作面不同的推进方向可导致不同的采动坡体活动方式,向沟开采时产生顺坡滑移,背沟开采时产生反坡倒转,但基岩型冲沟与沙土质型冲沟引起坡体活动的机理不同。(2)首次提出基岩型冲沟采动坡体的“多边块”铰接结构,分析了坡角不同对该结构的影响特征,建立了相应的稳定性分析力学模型;得出坡角越大,基岩厚度越小,该结构越易产生滑落失稳,并计算出控制多边块体滑落失稳的支护阻力。(3)首次提出沙土质型冲沟坡体下浅埋煤层基本顶初次破断的不对称性,建立了与基本顶初次来压和周期来压相对应的结构力学模型,并进行了结构稳定性和“支架—围岩”关系分析,计算出控制顶板结构滑落失稳的支护阻力。(4)现场实测结果验证了两种典型冲沟采动坡体下工作面支护阻力计算的有效性,并表明:背沟开采时工作面支护阻力呈减小趋势,顶板控制的重点区域为采动坡体的下段;在煤层埋深一定的条件下,冲沟深度越大,坡角越大,采动坡体对工作面顶板的反作用效应越大。(5)基于大量实测和数值计算结果分析,首次提出冲沟切割系数的概念,并依据冲沟切割系数与坡角两个指标,对冲沟坡体进行了采动敏感性分类,可有效地指导矿井的安全高效生产。论文共有图116幅,表26个,参考文献152篇(外文文献38篇)。更多还原

【Abstract】 Crossing geomorphologic characterization of gully causes that interaction of fluctuating surface and shallow coal seam mining is more sensitive and intense in China northwest mining area, especially, kinds of gully-slope in surface, causes strata-pressure behavior to occur new characters in underground coalface, and has the adverse effect to coalmines safe highly effective production. Taking two kinds of typical mining-induced slopes of bedrock and sand-soil to as research objects and coalface back-gully advancing to as main mining method in this paper, mining-induced slope activity mechanism and its control of shallow coal seam in gully-wide-growth mining field have been systematically analyzed by laboratory physical simulation, numerical simulation, theoretical analysis and field observation methods etc, and which could guide engineering practice initially. Innovative achievements of this dissertation have been displayed as follows:(1)Different mining-induced slope activity way deriving from different advancing direction of coaface has been revealed and proved first time. Down-slope sliding occurs for toward-gully mining, while reverse-slope rotating for back-gully mining, but the slope activity mechanism deriving from bedrock-gully and sand-soil-gully is different.(2)Multilateral block hinged structure of bedrock-gully mining-induced slope has been proposed for the first time, influence characteristics of different slope angle to the structure has been analyzed, and corresponding mechanical model of stability analysis has been founded; angle of gully is the bigger and thickness of bedrock is smaller, the structure is much easier to sliding instability, and supporting resistance of controlling multilateral block sliding instability has been calculated out.(3)The main roof first breakage asymmetry of shallow coal seam under sand-soil-gully slope has been proposed first time, corresponding structure mechanical model of main roof first weighting and periodic weighting has been founded, and the relation between structure stability and“support-surrounding rock”has been analyzed, supporting resistance of controlling roof structure sliding instability has been calculated out.(4)The coalface supporting resistance calculation validity under two kinds of typical gully-slope has been validated by actual measure results, which shows that the coalface supporting resistance occurs reducing tendency for back-gully mining and the key point of roof controlling is below segment of mining-induced slope.(5)Based on mass actual mesure and numerical calculation results analysis, the gully-slope cutting-coefficient concept has been proposed for the first time, according to two index of cutting-coefficient and slope angle, mining insenstivity classification has been done on gully-slope, which might guide coalmines safe highly effective production116 pieces of figures, 26 pieces of tables and 152 pieces of consult documents (38 pieces of foreign literatures inside)have been quoted in this dissertation.更多还原