百子煤矿上行开采可行性研究

发布时间：2018-08-01 09:45

【摘要】：上行开采过程中,若下部煤层采用柱式开采,则在采动压力的影响下,可能造成层间岩体及下部煤层采空区遗留煤柱的失稳,进而引起上覆岩层的垮落破坏和长壁工作面底板岩层的失稳,威胁上部煤层采煤工作面的安全生产。因此,开展柱采区域上方煤层上行开采可行性的研究非常必要。论文以百子煤矿为研究对象,综合运用理论分析、物理模拟和数值模拟的方法,对柱式开采的8号煤层上部5号煤层上行长壁开采的可行性进行了研究。理论分析将采动压力作为分析上行开采可行性的关键参数,给出了采动压力的预计公式,得出8号煤层与5号煤层之间最小厚度20m层间岩体的最大破坏深度为3.2m,层间岩体抗拉强度和抗剪强度稳定性系数分别为5.9和4.1,并基于有效面积理论得出下伏8号煤层所留煤柱稳定性系数为2.2,表明层间岩体与8号煤层所留煤柱保持稳定。物理模拟实验研究表明,8号煤层柱式开采过程中承受的最大支承压力为2.965Mpa;5号煤层长壁推进过程中,老顶初次来压步距在58m左右,周期来压平均步距16.7m,来压过程中的采动压力仅影响层间岩体的一定深度,层间岩体保持稳定;5号煤层采空区域下方底板岩层中形成明显的减压区域,且顶板来压时仅在切眼处保护煤柱与煤壁前方煤体下方的传感器上出现应力集中现象,但监测到的煤柱支承压力值均小于4MPa,远低于8号煤层煤柱的承载强度,表明5号煤层上行开采过程中8号煤层所留煤柱保持稳定;数值模拟实验揭示了5号煤层长壁开采过程中8号煤层所留煤柱与层间岩体的应力分布与演化规律,表明百子煤矿上行开采时层间岩体和下伏8号煤层煤柱均具有足够的强度,不会发生失稳现象。论文研究成果对于百子煤矿的上行开采具有指导意义,对于其它类似开采条件煤矿的上行开采也具有良好的借鉴意义。
[Abstract]:In the process of upward mining, if pillar mining is used in the lower coal seam, under the influence of mining pressure, it may cause instability of the coal pillar left over from the interlayer rock mass and the goaf of the lower coal seam. It also causes the collapse of overlying strata and the instability of the floor strata of longwall working face, which threatens the safe production of coal mining face in the upper coal seam. Therefore, it is necessary to study the feasibility of upward coal seam mining in pillar mining area. Taking Baizi coal mine as the research object, the feasibility of mining the governor wall on the upper and 5th coal seam of No. 8 coal seam is studied by using the methods of theoretical analysis, physical simulation and numerical simulation. In the theoretical analysis, the mining pressure is regarded as the key parameter to analyze the feasibility of upstream mining, and the prediction formula of mining pressure is given. It is concluded that the maximum failure depth of 20m interlayer rock mass is 3.2 m, and the stability coefficients of tensile strength and shear strength of interlayer rock mass are 5.9 and 4.1, respectively. Based on the theory of effective area, the maximum failure depth of 20m interlayer rock mass of No. 8 coal seam is obtained. The stability coefficient of coal pillar in coal seam is 2.2, which indicates that the interlayer rock mass and coal pillar left in No. 8 coal seam remain stable. The physical simulation results show that the maximum bearing pressure during pillar mining of No. 8 coal seam is 2.965Mpa. during the long wall propulsive process of No. 5 coal seam, the initial pressure step distance of the main roof is about 58m. The average step distance of periodic pressure is 16.7 m, and the mining pressure only affects the depth of the interlayer rock mass, and the interlayer rock mass remains stable, and an obvious decompression area is formed in the bottom rock layer under the goaf of No. 5 coal seam. When roof pressure comes to press, only the stress concentration phenomenon appears on the sensor under coal pillar and coal body in front of coal wall, but the supporting pressure value of coal pillar is less than 4MPa, which is far lower than the bearing strength of No. 8 coal pillar. The results show that the pillar of No. 8 coal seam remains stable during the upward mining process of No. 5 coal seam, and the stress distribution and evolution law of the pillar and interlayer rock mass of No. 8 coal seam during the long wall mining process of No. 5 coal seam are revealed by numerical simulation. The results show that both the interlayer rock mass and the coal pillar of No. 8 coal seam in Baizi coal mine have sufficient strength and there will be no instability. The research results of this paper have guiding significance for the upstream mining of Baizi coal mine, and also have good reference significance for other similar mining conditions.
【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】：TD823

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