风积沙区高强度开采覆岩与地表变形机理及特征研究

发布时间：2018-07-14 07:40

【摘要】：地处陕蒙交界的神府东胜矿区,地表被厚风积沙所覆盖。该地区煤炭资源丰富,煤层厚度大,埋藏浅,基岩薄,地质条件简单。目前在神东矿区已形成了高强度、高效率的地下开采模式。风积沙区高强度开采引起覆岩破坏严重,地表移动变形剧烈,覆岩破坏与地表变形呈现出特殊规律。基于神东矿区地质采矿条件,通过对地表移动变形实测资料分析,得到了风积沙区高强度开采引起地表移动变形的动静态角量参数和预测参数,分析了各类参数呈现特殊规律的原因。从地表移动变形与变形速度关系的角度,分析了高强度开采地表动态变形的全过程。总结了高强度开采地表非连续变形规律,地表裂缝总是呈“带状”形态以一定间距发生于工作面前方,而每两条“带状”裂缝之间,又分布若干细小裂缝。当工作面推进过后,在风积沙和应力压缩作用下,地表裂缝又呈现出逐渐闭合的特征。揭示了地表裂缝宽度与周期来压之间的关系。在分析覆岩破坏类型及特征的基础上,发现了在浅埋深、风积沙区高强度开采时覆岩存在“两带”破坏形式。构建了符合高强度开采冒落带、导水裂缝带计算新公式,给出了较为符合高强度开采实际的“两带”高度。通过采用数值模拟手段,分析了风积沙区高强度采动覆岩应力分布特征,揭示了采动覆岩从弹性区到塑性区演化过程和覆岩变形机理。利用相似材料模拟实验,分析了覆岩破坏与地表变形之间的关系,得到覆岩冒落带、导水裂缝带发育高度。基于关键层理论,揭示了开采覆岩结构及其破断机理,并进行了实例分析。为浅埋深、厚风积沙下煤层安全高效开采提供一定参考。
[Abstract]:Located at the junction of Shanxi and Mongolia Shenfu Dongsheng mining area, the surface is covered by thick aeolian sand. This area is rich in coal resources, large thickness of coal seam, shallow burial, thin bedrock and simple geological conditions. At present, high intensity and high efficiency underground mining mode has been formed in Shendong mining area. High intensity mining in aeolian sand area caused serious overburden damage and severe surface movement and deformation, which showed a special law of overburden failure and surface deformation. Based on the geological and mining conditions of Shendong mining area, the dynamic and static angular parameters and prediction parameters of surface movement and deformation caused by high intensity mining in aeolian sand area are obtained by analyzing the measured data of surface movement and deformation. The reasons for the special regularity of various parameters are analyzed. From the point of view of the relationship between surface movement deformation and deformation velocity, the whole process of ground dynamic deformation in high strength mining is analyzed. In this paper, the law of surface discontinuous deformation in high intensity mining is summarized. The surface cracks always take the form of "banding" and occur in a certain distance in front of the face, and between each two "banded" cracks, some small cracks are distributed. When the face is pushed forward, the surface cracks are gradually closed under the action of aeolian sand and stress compression. The relationship between surface crack width and periodic pressure is revealed. Based on the analysis of the failure types and characteristics of overburden rocks, it is found that there are "two zones" failure forms of overburden rocks in shallow buried depth and high intensity mining in aeolian sand area. A new formula for calculating high strength mining caving zone and water conduction fracture zone is constructed, and the "two zones" height which accords with the actual situation of high strength mining is given. By means of numerical simulation, the stress distribution characteristics of high strength mining overburden in aeolian sand area are analyzed, and the evolution process of mining overburden from elastic zone to plastic zone and the deformation mechanism of overburden are revealed. The relationship between overburden failure and surface deformation is analyzed by using similar material simulation experiments. The overburden caving zone and the height of water-conducting fracture zone are obtained. Based on the critical layer theory, the mining overburden structure and its fracture mechanism are revealed, and an example is analyzed. It provides a certain reference for the safe and efficient mining of coal seam under shallow buried depth and thick eolian sand.
【学位授予单位】：河南理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD325

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