【作者】 董钢锋；

【导师】 胡千庭； 戴广龙；

【作者基本信息】 安徽理工大学 ， 安全技术及工程， 2013， 博士

【摘要】 我国西北地区煤炭资源埋藏浅,表土层薄,但是煤层厚度大,且层数多,多为煤层群开采。因此在工作面开采过程中,上下邻近层瓦斯涌出的不同特点,将对采动瓦斯的治理带来不同的影响。掌握不同开采条件下采动瓦斯分布规律,可以为分析采动瓦斯涌出后对瓦斯进行抽放提供理论依据,是治理瓦斯的前提。而研究不同条件下采空区上覆岩层的变形破坏规律,确定采动上覆岩石“三带”的范围,也是掌握采动瓦斯流动规律并最终进行采动瓦斯抽放的关键和前提。因此,研究煤层群开采条件下,不同开采顺序所造成的覆岩变形破坏规律以及由此带来的采动瓦斯分布规律,将为矿井回采工作面及上隅角瓦斯治理问题带来理论依据,具有重要的学术意义,也具有重要的技术和经济价值。论文依托内蒙古科技厅重大项目“乌达矿区高瓦斯矿井瓦斯抽采技术及综合利用研究”,以五虎山煤矿生产实际为基础,针对煤层群开采条件下采动瓦斯分布规律和治理技术,从以下几个方面展开了研究并得出结论：(1)通过煤岩样品的实验室测试,获得了煤层及顶板的密度、弹性模量、泊松比、单轴抗压强度等基本物理力学参数,为接续研究工作的开展奠定了基础。(2)通过理论分析,在总结前人研究的基础上,建立采动瓦斯分布的数学模型,并对模型进行量化求解。(3)采用理论分析和数值模拟的方式研究煤层群开采过程中采动空间应力、裂隙分布规律。根据应力场模拟结果,首采上层煤时,垮落带最大高度约为10.9m,断裂带最大高度约为22.9m。首采下层煤时,垮落带最大高度约为14.8m,断裂带最大高度约为距本煤层顶板49.4m。覆岩裂隙场研究结果表明：覆岩裂隙场内,裂隙数量分布以两边为多,中部较少,在关键层下部的岩层往往产生较大的离层空间；覆岩底部,孔隙率较大,孔隙率曲线沿走向呈现马鞍状。(4)在理论分析和数值模拟的基础上,研究了上、下邻近层对开采层工作面采空区瓦斯分布规律,得出了不同瓦斯涌出来源(上邻近层和下邻近层)条件下尾巷对采空区瓦斯流动的影响规律,总结形成回采空间采动瓦斯流场分布规律。(5)顶板走向高位钻孔布孔参数设计及参数合理化研究。根据前面的研究成果结合试验工作面的具体情况,设计3-4组不同钻孔数量、钻孔深度的顶板走向高位抽放钻场,通过考察钻孔抽采量与推进距离、推进速度、抽采时间等抽采参数进行现场验证。理论分析和现场考察结果表明：1)首采下层煤时,工作面回风巷内施工的各个钻场内的下、中和上分层钻孔与工作面推进均有一个时空关系,但下分层钻孔处于裂隙发育区段的时间最长,整体抽放效果最好；上分层抽放效果次之,中分层钻孔效果最差。2)首采上层煤时,工作面高位钻孔考察结果证明钻孔抽采的适宜层位与前述“三带”范围的理论分析基本一致；工作面高位钻孔抽采效果不佳,同样表明了尾巷对采空区瓦斯流场分布的研究是正确的。通过以上几个方面的系统研究,掌握了试验工作面的瓦斯涌出来源,确定了回采工作面采动瓦斯分布规律、顶板走向高位钻孔与工作面回采的时空演化关系和顶板走向高位钻孔合理化参数,总结形成了适合五虎山煤矿开采条件下的瓦斯治理技术,为该矿回采空间的瓦斯治理提供了技术支持。更多还原

【Abstract】 In North west China,coal are of the characteristics of shallow burial depth, epipedon thin, large thickness and Multi-Layers.There will be different effect on the gas control because different gas resources.Mastering the gas distribution laws in goaf is the premise of extracting and control gas.Determining and analyzing the deformation failure laws of Strata Especially the the range of three-belts is the most important thing.Different gas distribution caused by different mining sequence.These studies will provide theoretical basis for controlling gas in extraction space. So these studies have import academic significance, technology and economic values. So relyed on the great project of Inner Mongolia technology department "Study on the Gas Drainage and Utilization of high gas mine in Wuda Coal Mining District" and production practice of Wuhushan mine, the thesis give a study on the gas distributiong and controlling technique under different conditions and get conclusions in the following aspects:(1)Basic mechanical parameters of coal,roof and floor such as density, elastic Modulus, poisson ratio,uniaxial compressive strength are got by laboratory test,which laid a foundation for the following works.(2) Mathematical model of gas flowing in goaf has been established by theoretical analysis and summarizing previous research.(3) The space-time evolution regularities of roof overburden falling in coal seams mining have been studied by theoretical analysis and numerical simulation.Stress Simulation showing that:the height of the watering fissures is22.9m and the height of caving zone is about10.9m after the mining of the over layer mining.After the under layer mining the height is about14.8m and49.4m.Crack field Simulation showing that:the development and distributing of the fracture fields are more at the edge and less at the middle.The porosity curve take a "saddle pattern" with the trend.(4) Gas distributiong laws in goaf, along the trend and tendency of face, along the transport tunnel and return airway have been studied by theoretical analysis and numerical simulation.Tailgate on effect law of goaf gas flow under different sources of gas emission have been studied by theoretical analysis and numerical simulation. Practice is further evidence of the correctness of the findings(5) Design and Optimization of high position bore-hole parameters along roof strike.3-4group drilling fields with different amount and different depth drillings will be designed.To investigated the relationship between the amount of drainage, advance distance, advance speed and the time of drainage.The results showing:1) Extracting results is the best of the drilling at Lower Slice and the poorest of the drilling at middle when the under layer is the first mining.The analytical results about diring layer and gas distributiong areconsistent with the Theoretical Analysis when the over layer is the first mining.2) In order to master the temporal and spatialevolutionary relationship with drilling and face mining.The final purpose is to determine the rationalizational spin-hole arrangement parameters.By above research, masterring the gas resources and gas distributiong laws in order to determine the temporal and spatialevolutionary relationship with drilling and face mining and the rationalizational spin-hole arrangement parameters.According to these studies, confirmed what technology functions are required and provide the technical support for gas controlling in Wu Hushan mine.更多还原