浅埋极近距离下层煤开采覆岩垮落规律与支护阻力研究

发布时间：2018-06-28 04:09

本文选题：极近距离煤层 + 斜台阶岩梁　；参考：《西安科技大学》2017年硕士论文

【摘要】：陕北侏罗纪煤田煤层群储量丰富,区内大部分矿井已进入下层煤开采。在极近距离煤层群的下层煤开采中,上层煤开采顶板已经垮落,顶板结构和应力环境发生改变,顶板的来压规律、机理和控制理论有待研究。揭示近距离煤层采空区下开采覆岩垮落规律,确定合理的支护阻力,成为陕北煤层群安全高效开采亟待解决的问题。霍洛湾煤矿2-2上煤层与2-2煤层间距为5～7m,属极近距离煤层开采,本文以2-2煤层22104工作面为研究对象,采用物理相似模拟实验、数值计算和顶板结构理论分析相结合的方法,研究了极近距离下层煤开采的顶板垮落和来压规律,建立了下层煤顶板结构模型,揭示了顶板来压机理,给出了支架阻力计算方法。物理模拟研究表明,下层煤初采阶段初次来压步距为20m,周期来压步距5～7.5m。采用UDEC数值模拟得出,顶板初次来压步距约18m,顶板周期来压步距平均7.5m。工作面超前支承压力峰值位于工作面煤壁前方1Om,峰值影响范围小于40m,且应力峰值小于煤体平均强度15.0MPa,对工作面煤壁稳定性影响不大。在采空区压实阶段,上层煤垮落顶板结构活化,呈现台阶式下沉,动载明显,具有“台阶岩梁”结构特征;工作面来压出现周期性“高压区”和“低压区”,高压区持续长度平均16m,高压区周期步距平均25m。上层煤垮落顶板结构活化是下层煤高压区的主要原因。高压区支架平均载荷7676kN/架,低压区平均载荷5580kN/架,高压区为低压区的1.37倍。煤柱区下支架载荷是高压区载荷的1.07倍。基于“台阶岩梁”理论,建立了极近距离下层煤开采顶板“活化斜台阶岩梁”结构模型,计算得出22104工作面支架工作阻力应大于8634kN/架。结合物理相似模拟实验,类似的石圪台12102工作面的支架选型及工作面矿压实测分析,确定霍洛湾煤矿22104工作面应选用额定工作阻力大于8800kN/架的液压支架,得到矿区采纳应用。
[Abstract]:The coal seam group in the Jurassic coal field in Northern Shaanxi is abundant, and most of the coal mines in the area have already entered the lower coal mining. In the lower coal mining of the very close coal seam group, the top coal mining roof has fallen down, the roof structure and stress environment change, the rule of the roof pressure, the mechanism and the control theory need to be studied. Mining the law of overlying rock collapse and determining reasonable support resistance have become an urgent problem to be solved for safe and efficient mining of coal seam group in Northern Shaanxi. The distance between 2-2 coal seam and 2-2 coal seam in hollowe coal mine is 5 ~ 7m, and it is very close to coal seam mining. This paper takes 22104 working face of 2-2 coal seam as the research object, and uses physical similar simulation experiment, numerical calculation and roof. The method of structural theory analysis is combined to study the roof collapse and pressure rule of the coal mining at the very near lower level. The structure model of the lower coal roof is set up, the mechanism of the roof pressure is revealed and the calculation method of the support resistance is given. The physical simulation study shows that the initial pressure step distance of the lower coal mining stage is 20m, and the periodic pressure step is 5 to 7.5. M. UDEC numerical simulation results show that the initial pressure step distance of the roof is about 18m, the peak pressure peak of the top plate cycle distance to the average 7.5m. working face is 1Om in front of the coal face, the peak value is less than 40m, and the peak stress is less than the average strength of the coal body 15.0MPa, which has little effect on the stability of the coal wall. The top coal caving roof structure is activated, showing a step type subsidence and obvious dynamic load, with a "step rock beam" structure, a periodic "high pressure zone" and a "low pressure zone" in the working face, the average length of 16m in the high pressure area, and the activation of the top coal caving roof structure in the upper layer of the high pressure zone, which is the main part of the lower coal high pressure area. The average load of the high pressure zone is 7676kN/, the average load of low pressure area is 5580kN/, the high pressure area is 1.37 times that of the low pressure area. The support load of the coal pillar area is 1.07 times the load of the high pressure area. Based on the "step rock beam" theory, a "activated inclined step rock beam" structure model of the top plate mining roof is established, and 22104 work is calculated. The working resistance of the surface support should be greater than that of the 8634kN/ frame. In combination with the physical similarity simulation experiment, the similar support type selection of the 12102 working face of the stone gedai and the measured analysis of the working face ore pressure, it is determined that the 22104 working face of hollowe coal mine should choose the hydraulic support with the rated working resistance greater than the 8800kN/ frame, and the application is adopted in the mining area.
【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】：TD823.81

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