薄煤层下保护层开采保护范围及卸压瓦斯抽采研究

发布时间：2018-03-17 18:52

本文选题：薄煤层　切入点：下保护层　出处：《贵州大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着煤炭资源开采深度的不断增加,煤与瓦斯突出危险性也逐渐增大。保护层开采作为防治煤与瓦斯突出最有效、最经济的区域防突措施,在我国得到了广泛应用。然而,目前有不少突出矿井只有薄煤层具备作为保护层开采的条件。因此,研究分析薄煤层保护层开采对被保护层的卸压作用具有十分重要的意义。本文以贵州省桐梓县大河煤矿为科研背景,运用理论分析、计算机数值模拟和现场考察的方式对其薄煤层下保护层开采后的保护范围及卸压瓦斯抽采进行研究,取得了以下主要研究成果和结论:(1)对下保护层开采上覆煤岩的移动特性和裂隙分布特征进行了分析。得出下保护层开采后,上覆煤岩自下而上将依次形成垮落带、裂隙带和弯曲下沉带。并得出大河煤矿10号下保护层开采后所形成的最大垮落带高度为4.8m,最大裂隙带高度为30.6m。被保护的7号主采煤层处于垮落带之上,裂隙带之中,对其应力及瓦斯压力的释放和卸压瓦斯的抽采极为有利。(2)运用FLAC3D数值模拟软件,对下保护层21002工作面开采后,上覆煤岩的垂直应力分布情况、垂直位移量大小和破坏程度进行了研究。结果表明,保护层开采后,对应的被保护层在走向方向上的垂直应力大致呈“W”形分布;垂直位移分布呈平底锅状,最大垂直位移发生在采空区中部。(3)运用计算机数值模拟结合不同的保护范围判别准则,对21002下保护层开采后对应7号被保护煤层的卸压保护范围进行了划定,并对保护范围进行了现场考察,绘制了考察点瓦斯含量分布趋势线图。结果表明,采用计算机数值模拟结合煤层法向变形判别准则所划定的保护范围与实际考察结果最接近,且趋于安全,可以为大河煤矿在下一步的开采工作中保护范围的划定提供科学依据。(4)提出采用底抽巷抽采和上、下顺槽穿层抽采的瓦斯治理方案,对大河煤矿下保护层开采的卸压瓦斯进行抽采。经现场统计得出,工作面瓦斯抽采率达到76.5%~82.3%,回采工作面回风流瓦斯体积分数稳定在0.41%~0.62%,卸压瓦斯治理效果显著,满足了回采工作面的生产需要。
[Abstract]:With the increasing depth of coal mining, the risk is also gradually increasing. Coal and gas outburst as protection layer mining of coal and gas outburst prevention is the most effective, the most economical and regional outburst prevention measures, has been widely used in China. However, there are a lot of thin coal seam with outburst mine only as a condition of protection layer mining. Therefore, research and analysis of thin coal seam mining protective layer of protective layer of the pressure relief effect is very important. In this paper, the river Tongzi County of Guizhou province coal mine as the research background, through theoretical analysis, numerical simulation and field research method of pressure relief gas drainage of the thin coal seam under protection the range of layer after mining and achieved the following conclusions: (1) to the under protective layer overlying coal rock movement characteristics and fracture distribution characteristics were analyzed. Through the protection layer After mining, overlying coal rock bottom-up formed caving zone, fractured zone and bending zone. And the river coal mine No. 10 under the protection of the maximum height of the caving zone is 4.8m layer mining after the formation of the maximum fracture zone height 30.6m. protected No. 7 main coal seams in caving zone on the fracture zone, the stress and the gas pressure release and pressure relief gas drainage is extremely beneficial. (2) using FLAC3D numerical simulation software, the protective layer of 21002 working face mining, the coal rock on the vertical stress distribution, vertical displacement and size of damage process was investigated. The results show that the protective layer mining, the corresponding protective layer was in the direction of the vertical stress is roughly "W" shape distribution; vertical displacement distribution in the pan, the maximum vertical displacement occurs in goaf middle. (3) using simulation combined with different protection of computer fan numerical Wai criterion of protection layer mining under 21002 after the corresponding 7 protected coal seam pressure relief protection area were delineated, and conducted a field investigation on the scope of protection, to draw the trend line distribution of gas content on map. The results show that the numerical simulation method to the deformation of coal layer protection combined with the criteria defined the scope and the actual inspection result is most close to, and tends to be safe, can provide a scientific basis for the delineation of the scope of protection of mining work in the next step of the river coal mine. (4) the bottom drainage roadway drainage and gas control scheme, trough wear layer drainage, the River coal mine protection layer mining pressure relief gas drainage. The statistical results, recovery rate of 76.5%~82.3% gas working face, coal face return air gas volume fraction at 0.41%~0.62%, pressure relief gas control effect, to meet the recovery The production needs of the working face.

【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD712.6

【相似文献】