大倾角煤层群综放采场顶板结构与支架载荷研究
发布时间：2018-09-17 09:22
【摘要】：我国西部矿区普遍赋存有倾角介于35°～55°之间的大倾角煤层。与近水平或缓斜煤层不同,大倾角工作面老顶岩层沿走向和倾向都能形成铰接结构。顶板的倾向结构和走向结构对支架载荷都有显著影响,属于空间结构问题。关于大倾角工作面支架载荷确定的研究,普遍接受的观点是支架除承担顶煤和直接顶载荷外,还要承担老顶的部分载荷,但老顶载荷如何准确计算是一个难题。实践表明,大倾角煤层直接顶垮落后,沿工作面滚落,不均匀的充填下部顶板,造成大倾角工作面顶板结构与支架载荷具有分区特征。而针对大倾角煤层群综放开采顶板结构与支架载荷的研究较少。本文以王家山煤矿工程地质和开采技术条件为背景,利用现场实测、物理模拟、数值模拟和理论分析等多种手段,研究了大倾角煤层群综放采场顶板结构与支架载荷关系。在物理模拟的基础上,建立了沿倾向和走向的顶板结构力学模型,3DUC数值模拟印证了物理模拟的结论。通过理论分析得到了大倾角煤层群综放采场中,上煤层及下煤层工作面支架载荷的计算公式。给出了兼顾支架防滑与抗中区顶压的额定工作阻力判据,通过开采实践验证了结论的可靠性。研究表明:大倾角煤层群上煤层开采后,关键层岩块沿倾向形成铰接结构,受顶板铰接结构和煤层倾角影响,顶板垮落高度减小,工作面支架的最大载荷为中区顶压。下煤层开采后,间隔层整体发生挠曲下沉,但关键层结构依然稳定。支架工作阻力在满足防止支架侧滑的前提下,主要承担顶煤、间隔层与上煤层垮落顶板的载荷。定义垂直于支架顶梁的载荷为“顶压”,支架间沿倾向传递的载荷为“侧压”,工作面支架顶压和侧压存在分区特征。上区支架顶压不大,支架易发生失稳:中区支架承受的顶压最大,额定工作阻力需要大于顶压,同时满足初撑力自稳条件:下区充填程度最好,顶板结构稳定,支架载荷不大,因此下煤层工作支架工作阻力以平衡中区顶压的条件来确定。通过实例验证,表明研究结果可靠,可为大倾角煤层综放开采顶板控制提供理论依据。
[Abstract]:Large dip coal seams with dip angle between 35 掳and 55 掳are commonly found in western mining areas of China. Different from the near horizontal or gently inclined coal seam, the main roof strata of large inclined face can form hinged structure along the direction and tendency. The inclined structure and strike structure of roof have significant influence on the load of support, which belongs to the problem of space structure. It is generally accepted that the support load should bear part of the main roof in addition to the top coal and direct top load, but how to calculate the main roof load accurately is a difficult problem. The practice shows that the roof structure and support load of the large inclined coal face are zoned because of the falling down along the working face and the uneven filling of the lower roof. However, there are few researches on roof structure and support load of fully mechanized caving mining in large inclined coal seam group. Based on the engineering geology and mining technical conditions of Wangjiashan coal mine, this paper studies the relationship between roof structure and support load in fully mechanized caving stope of large inclined coal seam group by means of field measurement, physical simulation, numerical simulation and theoretical analysis. On the basis of physical simulation, the model of roof structure mechanics along the tendency and trend is established. The conclusion of the physical simulation is confirmed by the numerical simulation of 3DUC. Based on the theoretical analysis, the formulas for calculating the support load in the top coal seam and the lower coal face in the fully mechanized caving stope with large dip coal seam are obtained. The criterion of rated working resistance is given, which takes into account both anti-skid and anti-top pressure of support, and the reliability of the conclusion is verified by mining practice. The research shows that after mining the upper coal seam of large dip coal seam group, the key strata rock block forms hinged structure along the inclination, which is affected by roof hinge structure and coal seam dip angle, the roof collapse height is reduced, and the maximum load of the support in the working face is the middle area top pressure. After the coal seam is mined, the whole interval layer is deflection and subsidence, but the structure of the key layer is still stable. The working resistance of the support mainly bears the load of top coal, spacer and upper coal seam caving roof under the premise of preventing the side slip of the support. The load perpendicular to the top beam of the support is defined as "top pressure", and the load transmitted along the inclination between the supports is "lateral pressure". The top pressure of the upper support is small, the support is vulnerable to instability: the top pressure of the central support is the largest, the rated working resistance needs to be greater than the top pressure, and the self-stability condition of the initial support force is satisfied: the filling degree of the lower area is the best, the roof structure is stable, and the load of the support is not large. Therefore, the working resistance of the working support in the lower coal seam is determined by the condition of balancing the top pressure in the middle area. The experimental results show that the research results are reliable and can provide a theoretical basis for roof control of fully mechanized caving mining in large inclined coal seam.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD327.2;TD355
[Abstract]:Large dip coal seams with dip angle between 35 掳and 55 掳are commonly found in western mining areas of China. Different from the near horizontal or gently inclined coal seam, the main roof strata of large inclined face can form hinged structure along the direction and tendency. The inclined structure and strike structure of roof have significant influence on the load of support, which belongs to the problem of space structure. It is generally accepted that the support load should bear part of the main roof in addition to the top coal and direct top load, but how to calculate the main roof load accurately is a difficult problem. The practice shows that the roof structure and support load of the large inclined coal face are zoned because of the falling down along the working face and the uneven filling of the lower roof. However, there are few researches on roof structure and support load of fully mechanized caving mining in large inclined coal seam group. Based on the engineering geology and mining technical conditions of Wangjiashan coal mine, this paper studies the relationship between roof structure and support load in fully mechanized caving stope of large inclined coal seam group by means of field measurement, physical simulation, numerical simulation and theoretical analysis. On the basis of physical simulation, the model of roof structure mechanics along the tendency and trend is established. The conclusion of the physical simulation is confirmed by the numerical simulation of 3DUC. Based on the theoretical analysis, the formulas for calculating the support load in the top coal seam and the lower coal face in the fully mechanized caving stope with large dip coal seam are obtained. The criterion of rated working resistance is given, which takes into account both anti-skid and anti-top pressure of support, and the reliability of the conclusion is verified by mining practice. The research shows that after mining the upper coal seam of large dip coal seam group, the key strata rock block forms hinged structure along the inclination, which is affected by roof hinge structure and coal seam dip angle, the roof collapse height is reduced, and the maximum load of the support in the working face is the middle area top pressure. After the coal seam is mined, the whole interval layer is deflection and subsidence, but the structure of the key layer is still stable. The working resistance of the support mainly bears the load of top coal, spacer and upper coal seam caving roof under the premise of preventing the side slip of the support. The load perpendicular to the top beam of the support is defined as "top pressure", and the load transmitted along the inclination between the supports is "lateral pressure". The top pressure of the upper support is small, the support is vulnerable to instability: the top pressure of the central support is the largest, the rated working resistance needs to be greater than the top pressure, and the self-stability condition of the initial support force is satisfied: the filling degree of the lower area is the best, the roof structure is stable, and the load of the support is not large. Therefore, the working resistance of the working support in the lower coal seam is determined by the condition of balancing the top pressure in the middle area. The experimental results show that the research results are reliable and can provide a theoretical basis for roof control of fully mechanized caving mining in large inclined coal seam.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD327.2;TD355
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