大采高综放工作面覆岩结构与支架载荷研究

发布时间：2018-03-21 17:45

本文选题：大采高综放　切入点：覆岩拱结构　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：巨厚煤层大采高综放开采一次采出煤层厚度大,岩层运移范围广,工作面煤壁片帮、支架被压死或损坏等问题严重制约大采高综放工作面安全高效生产。因此研究大采高综放工作面覆岩移动破坏规律、结构特征、支架载荷,对巨厚煤层大采高综放开采实现安全高效生产具有重要的意义。本文以鄂尔多斯大唐龙王沟煤矿6#煤层在6~上煤采与未采两种条件下进行大采高综放开采(采5m放15m)对比试验为例(工程类比法取支架额定工作阻力15000kN),采用相似材料模拟实验及数值计算研究了工作面覆岩结构特征、应力演化规律及支架载荷。结果表明6~上煤未采条件下,覆岩拱结构发育范围小其内可形成砌体梁结构,工作面矿压显现缓和,工作面可安全生产。6~上煤已采条件下,覆岩拱结构发育范围大其内形不成砌体梁结构,工作面煤壁片帮严重、支架频繁被压死,因此认为在6~上煤采空区下进行6#煤开采是不可行的。分析研究6~上煤采空区下进行6#煤大采高综放开采覆岩移动破坏规律知,岩层移动破坏范围广,采空区不能有效充填,因此采空区对围岩的约束减小,同时6~上煤开采时上覆岩层受采动影响强度减弱导致工作面前方出现超前拉裂裂隙。超前裂隙的存在造就了工作面与超前裂隙之间存在超前岩柱,超前岩柱向采空区的回转致使工作面煤壁片帮严重,支架受力陡然增大直至被压死。基于上述分析综合对比两种开采条件下6#煤层开采覆岩运移规律知,工作面推进过程中形成的拱结构与工作面存在拱结构滞后于、同步于、超前于工作面三种位置关系,三种位置关系下工作面矿压显现差异明显。拱顶坚硬岩层控制着拱结构的发育,对其建立力学模型明确了拱结构与工作面三种位置关系的判定条件并进行验算。同时建立拱结构超前于工作面情况下支架受力的力学模型给出了工作面液压支架工作阻力计算公式,并进行验算所得结果与实验实测值基本吻合。
[Abstract]:The thickness of coal seam is large, the range of strata migration is wide, and the face wall is covered by fully mechanized caving caving with large mining height in very thick coal seam. The problems such as dead or damaged support seriously restrict the safe and efficient production of fully mechanized top-coal caving face with large mining height. Therefore, the law of movement and destruction of overburden, structural characteristics, load of support are studied in fully mechanized top-coal caving face with large mining height. It is of great significance to realize safe and efficient production by fully mechanized top coal caving mining in very thick coal seams. In this paper, 6 # coal seam of Datang Longwanggou Coal Mine, Ordos, is used for fully mechanized caving mining (5 m mining) under the condition of 6 ~ top coal mining and no mining. A comparative test of 15m is used as an example (the nominal working resistance of the support is measured by using the engineering analogy method, and the structural characteristics of the overburden rock in the working face are studied by using the similar material simulation experiment and numerical calculation. The results show that the masonry beam structure can be formed in a small development range of overburden arch structure under the condition of 6 ~ # coal unmining, the mine pressure of the working face is relaxed, and the working face can be safely produced under the condition of coal mining. The overburden arch structure has a large development range and its inner shape does not form a masonry beam structure. The coal wall of the working face is serious and the support is pressed to death frequently. Therefore, it is considered that it is not feasible to mine 6 # coal under the goaf of 6 ~ # top coal. The analysis and study on the rule of overburden rock movement of 6 # coal mining height fully mechanized caving mining under 6 ~ top coal mining goaf shows that there is a wide range of strata movement and damage, and the goaf cannot be filled effectively. Therefore, the constraint of goaf on surrounding rock is reduced, At the same time, in 6 ~ # coal mining, the overburden strata are weakened by the influence of mining movement, which leads to the ahead tension crack in front of the face. The existence of the leading crack results in the existence of the leading rock column between the working face and the leading fissure. The rotation of the leading rock column to the goaf leads to the serious coal wall cover in the working face, and the support force increases suddenly until it is crushed to death. Based on the above analysis and comprehensive comparison of the overlying rock migration law of the 6 # coal seam mining under the two mining conditions, it is known that, The arch structure formed in the process of working face advancing and the arch structure existing in the face lags behind, synchronizes, and is ahead of the three kinds of position relations of the working face. There are obvious differences in the rock pressure behavior of the working face under the three position relationships. The arch structure is controlled by the hard rock layer of the arch roof. The condition of determining the relationship between the arch structure and the three positions of the working face is determined and checked. At the same time, the mechanical model of the support bearing force ahead of the working face is established, and the working face hydraulic support is given. Working resistance calculation formula, The results are in good agreement with the experimental data.
【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】：TD325

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