房柱式开采条件下上覆岩层活动规律及上行开采可行性研究

发布时间：2018-10-08 19:45

【摘要】：本文以同生精通兴旺煤矿实际地质条件和前期生产情况为研究背景，采用现场调研和实践、理论分析以及数值计算分析等方法对下部煤层房柱式开采条件下上覆岩层的活动规律进行了研究，并在此基础上分析上部煤层受下部煤层房柱式开采的采动影响程度，论证上行开采的可行性。为全面分析下部煤层不同的房柱式开采对上覆岩层活动规律的影响，在结合煤矿实际生产情况的基础上，论文运用正交分析原理，考虑到采宽、留宽等主要因素对煤柱稳定程度以及上覆岩层活动变形的影响，数值模拟采留比、采宽两因素影响下12号煤层的房柱式开采，在此基础上对上部9号煤层采用分步开挖进行数值模拟，研究下部煤层房柱式开采以及上行开采上部煤层过程中，采留比、采宽等因素对房柱式煤柱及其上覆岩层活动变形的影响。论文的主要研究结果如下： 1.当采留比在1/2到2范围内时，采宽保持不变，采留比越大，应力越容易在煤柱上集中，煤柱的稳定性越差，采留比不变，采宽越大（所留煤柱越宽），煤柱的稳定性越好，承压能力强。上部煤层回采过程中，二次采动的影响会进一步影响煤柱的稳定性，受到超前支撑压力的作用，处于极限稳定状态的煤柱容易失稳垮落。 2.下部煤层房柱式开采后应力形成“增压区”和“卸压区”的交替分布，使上覆岩层产生不同程度的活动变形；当采留比在1/2到2范围内时，采宽保持不变，采留比越小，应力交替式分布越明显，采宽内越容易形成波浪，，采宽越大，波浪越明显。受超前支撑压力的影响，上部煤层二次采动会进一步加剧交替式分布，波浪进一步向上发展。 3.经过理论分析和数值模拟计算，同生精通兴旺煤矿9号煤层处于下部煤层开采后的裂隙带，在平衡岩层之上，能够形成平衡岩层结构而不发生台阶错动，可在12号煤层房柱式采空区的上部上行开采9号煤层。
[Abstract]:In this paper, based on the background of the study on the actual geological conditions and early production conditions of the flourishing coal mine, the field investigation and practice are adopted in this paper. Theoretical analysis and numerical analysis are used to study the activity of overlying strata under the condition of roof pillar mining in the lower coal seam, and on the basis of this, the influence of roof pillar mining on the upper coal seam is analyzed. The feasibility of upstream mining is demonstrated. In order to analyze the influence of different roof pillar mining in the lower coal seam on the activity law of overburden strata, based on the actual production situation of coal mine, the paper applies the principle of orthogonal analysis to consider the mining width. The influence of main factors, such as retaining width, on the stability of coal pillar and the active deformation of overlying strata, the numerical simulation of mining and retention ratio, and the influence of two factors, such as mining width, on the roof pillar mining of coal seam 12, are discussed. On the basis of this, numerical simulation is carried out on the upper 9 coal seam by step excavation, and the mining and retention ratio in the upper coal seam is studied in the lower coal seam, the roof pillar mining and the upper coal seam up mining. The influence of mining width and other factors on the deformation of roof pillar and its overlying strata. The main research results are as follows: 1. When the mining retention ratio is in the range of 1 / 2 to 2, the mining width remains constant, and the larger the mining retention ratio, the easier the stress is to concentrate on the coal pillar, the worse the stability of the pillar, the less stable the pillar, the wider the mining width (the wider the coal pillar is left), the better the stability of the pillar is. Strong bearing capacity. In the mining process of upper coal seam, the influence of secondary mining will further affect the stability of coal pillar, which is affected by the leading supporting pressure, and the pillar in the state of ultimate stability is easy to collapse. 2. After the roof pillar mining in the lower coal seam, the stress forms alternating distribution between the "pressurized zone" and the "pressure relief zone", which causes the overburden strata to produce varying degrees of active deformation, and when the mining / retention ratio is within 1 / 2 to 2, the mining width remains unchanged and the mining / retention ratio is smaller. The more obvious the stress alternating distribution is, the easier the wave is in the wide mining, and the larger the mining width is, the more obvious the wave is. Under the influence of leading support pressure, the secondary mining of upper coal seam will further aggravate the alternating distribution and further develop the wave. 3. Through theoretical analysis and numerical simulation calculation, the fracture zone of No. 9 coal seam in Xingxing Coal Mine after mining in the lower coal seam can be formed on the balance rock layer without the staggered step. Coal seam No. 9 can be mined in the upper part of the roof pillar goaf of No. 12 coal seam.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD823

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