鑫瑞煤矿极近距离下位煤层开切眼布置与围岩控制技术研究

发布时间：2018-05-28 10:13

本文选题：极近距离煤层 + 采空区　；参考：《中国矿业大学》2015年硕士论文

【摘要】：对于极近距离煤层,下位煤层开采前顶板的完整性受上位煤层开采损伤影响,其上又为上位煤层开采垮落的矸石,且上位煤层开采后遗留煤柱在底板形成的集中应力,导致下位煤层开采区域的顶板结构和应力环境发生变化,从而使下位煤层开采与单一煤层开采相比出现了许多新的矿山压力现象。本论文通过理论分析、数值模拟、工业性试验相结合的方法,分析了鑫瑞煤矿4#煤层采完后,5#煤层所处的应力环境,深入、系统地研究极近距离下位煤层开切眼围岩应力环境及其变形规律,确定合理巷道布置位置及其围岩控制技术,取得了以下结论:(1)研究了极近距离上层煤开采对下位煤层的影响,得出了4#煤层工作面采完之后,遗留煤柱边缘出现垂直应力集中的现象,应力峰值达到13MPa,应力集中系数达到2.6左右,采空区下方应力较小,并得到了上层煤4#煤开采后底板破坏深度为6m左右,4#煤的开采影响了5#煤层顶板的完整性,下层煤巷道布置时应考虑上层煤开采的影响。(2)得到了下煤层开切眼布置在不同位置时,围岩塑性区分布与变形规律,将开切眼布置在采空区下方与上层煤煤柱的外错距为4m,此时围岩变形量小、易于支护。(3)得到了开切眼不同成巷方式下围岩塑性区分布及变形规律,确定1501工作面开切眼采用先掘4.5m再扩刷成巷的方式为最优,提出了采空区下方的开切眼支护技术及方案,当顶板使用锚杆支护时无法在破裂(碎)围岩中或采空区内有效锚固时,提出采用水力膨胀锚杆替代螺纹钢锚杆的支护方式。(4)确定了位于采空区下方的1501工作面开切眼支护参数:当采用锚杆支护时,锚杆预紧力矩不小于300N·m,锚杆直径为22mm;当采用水力膨胀锚杆时,选用直径为28 mm、长度为2.4 m的水力膨胀锚杆,顶锚杆间排距为700mm×700mm,帮锚杆间排距为700mm×800mm。(5)在1501工作面开切眼成功进行了工业性试验,有效控制了切眼围岩变形,支护参数合理,能够满足生产要求。
[Abstract]:For the very close distance coal seam, the integrity of the roof before mining in the lower coal seam is affected by the damage of the upper coal seam mining, and the upper coal seam mining gangue, and the concentrated stress formed by the coal pillar left behind in the floor after the upper coal seam mining. As a result, the roof structure and stress environment in the mining area of the lower coal seam are changed, which makes the mining of the lower coal seam appear a lot of new pressure phenomenon compared with the single coal seam mining. Through theoretical analysis, numerical simulation and industrial test, this paper analyzes the stress environment of coal seam in Xinrui coal mine after mining. This paper systematically studies the stress environment and deformation law of surrounding rock of open and cut hole in very close distance coal seam, determines the location of reasonable roadway layout and the control technology of surrounding rock, and obtains the following conclusion: 1) the influence of coal mining on lower coal seam from very close distance is studied. It is concluded that vertical stress concentration appears at the edge of coal pillar after coal face mining in the coal face. The peak stress value is 13 MPA, the stress concentration factor is about 2.6, and the stress under the goaf is small. It is also obtained that the mining of floor failure depth of 6 m or so affects the integrity of coal seam roof. When the lower coal roadway is arranged, the influence of the upper coal mining should be taken into account.) the distribution and deformation of surrounding rock plastic zone are obtained when the opening and cutting holes of the lower coal seam are arranged in different positions. The outer offset between the open hole and the upper coal pillar is 4 m under the goaf, and the deformation of surrounding rock is small and easy to be supported. The plastic zone distribution and deformation law of surrounding rock under different roadways are obtained. It is determined that the method of opening and cutting holes in 1501 working face is the best way of digging 4.5m and then brushing the roadway first. The technology and scheme of opening and cutting support under goaf are put forward. When the roof can not be effectively anchored in the cracked (broken) surrounding rock or in the goaf when the roof is supported by bolting, The support method of hydraulic expansion bolt instead of rebar bolt is put forward. The parameters of open hole support of 1501 working face under goaf are determined: when bolting is used, The pre-tightening moment of the anchor rod is not less than 300N m and the diameter of the anchor rod is 22mm. When the hydraulic expansion anchor rod is used, the hydraulic expansion anchor rod with the diameter of 28 mm and the length of 2.4 m shall be selected, The roof bolt row distance is 700mm 脳 700mm, and the side anchor rod row distance is 700mm 脳 800mm. Y5) the industrial test has been successfully carried out in 1501 face opening and cutting hole, which effectively controls the surrounding rock deformation of the cutting hole, and the supporting parameters are reasonable, which can meet the requirements of production.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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