【作者】 潘宏宇；

【导师】 李树刚；

【作者基本信息】 西安科技大学 ， 安全技术及工程， 2009， 博士

【摘要】 随着开采深度及强度的增加,一些相距较近的坚硬岩层随采动影响出现了复合效应,由此产生的矿山压力显现对煤层瓦斯抽采提出了新的课题。因此,研究坚硬岩层的复合效应及其对煤层瓦斯渗流规律的影响,对于指导复合关键层下煤层瓦斯抽采具有重要的理论和工程意义。论文主要研究成果如下:(1)在关键层理论基础上,利用复合材料结构力学理论,建立Winkler地基上复合关键层模型,对复合关键层判别进行分析,并计算Winkler地基上复合关键层破断距。利用复合关键层挠曲在其紧邻下部岩层形成的支承压力向深部传递、扩散和衰减,求得了复合关键层下煤体支承压力,分析了复合关键层下煤体极限平衡区宽度,为复合关键层下工作面跨落步距的确定及支架选型提供了理论依据。(2)运用FLAC3D数值模拟,对比分析了复合关键层、组合关键层与非复合关键层的破断规律、支承压力分布与煤体变形规律;应用物理模拟实验,分析得出了复合关键层破断与采场支承压力分布规律,有效揭示了关键层的复合效应。(3)利用煤样全应力应变过程渗透特性的电液伺服试验,测定了煤体的气体渗透率,并分析了应力、应变、孔压等对煤体渗透系数的影响;建立了复合关键层下煤层瓦斯渗流耦合数学模型,并对煤层瓦斯渗流耦合模型进行了时间变量的离散、表征单元体解析及煤体变形场方程的离散,为渗流耦合数学模型的数值计算奠定了基础。(4)通过RFPA2D数值模拟,分析了复合关键层和非复合关键层对本煤层支承压力及瓦斯渗流的影响,分析了两种条件下开采引起的上覆岩层运动、支承压力和瓦斯渗透系数变化的规律。(5)通过亭南煤业公司101综放面矿压观测与瓦斯涌出监测,得出工作面来压步距与煤体支承压力,与Winkler地基复合关键层理论计算结果相近;分析了支承压力与煤体变形对瓦斯涌出的影响,其瓦斯涌出规律与渗流耦合模型数值计算结果相似,从现场实例验证了论文理论分析的正确性;在此基础上,对工作面煤层瓦斯预抽参数进行了优化设计。论文通过复合材料结构力学理论建立了Winkler地基复合关键层模型,对复合关键层破断距及工作面前方支承压力进行了分析,在此基础上建立了复合关键层下煤层瓦斯渗流耦合模型,将研究成果成功应用于亭南煤业公司101综放面,并对101综放面煤层瓦斯预抽参数进行了优化设计,抽放效果显著,取得了一定的经济和社会效益。更多还原

【Abstract】 With the depth and intensity of exploitation increase, some proximal hard rock appeared composite effect, the resulting rock press appearance has greater challenges to gas drainage in coal seam. So studying hard rock’s composite effect and its influence to the rule of coalbed methane seepage’s, has great theoretical and engineering significance for guiding gas drainage in coal seam in the condition of composite.The main contents:(1)Using composite material structural mechanics theory, analyzed Composite Key Stratum’s force theoretically, detruded Winkler foundation Composite Key Stratum’s interval. Using advanced press’pass、spreading and attenuation to deep, which formed by Composite Key Stratum’s flexure in its very near under stratum, achieved coal mass advanced press in the condition of Composite Key Stratum structure. Provided theoretical basis for determining working face’s cross-off pace and support lectotype in the condition of Composite Key Stratum.(2)Using RFPA3D numerical simulation, contrastively analyzed the interval law、advanced press distribution and coal mass’deformation law of Composite Key Stratum、combination Key Stratum and anti-Composite Key Stratum; Applied physical modeling experiments analyzed and got the law of Composite Key Stratum interval and advanced pressure distribution, effectively revealed the combined effects of Key Stratum.(3)Using coal sample’s electro-hydraulic servo test of complete stress-strain process infiltration characteristics, determined coal rocks’gas permeability, and analyzed the impact of stress, strain, pore pressure; Built coal-bed methane seepage coupled mathematical model in the influence of Composite Key Stratum, meanwhile, discussed time variable discretization、representative elementary volume analysis and coal mass formation field equation discretization to coal-bed methane seepage coupled mathematical model.(4)Using RFPA2D numerical simulation, considered the impact of Composite Key Stratum and anti-Composite Key Stratum on the advanced pressure and gas seepage of the coal seam, analyzed the change rule of overlying strata movement、advanced pressure and gas permeability coefficient caused by mining in these two structures.(5)Through the rockburst observation and gas monitoring in 101 fully mechanized top-coal caving face of Ting Nan mine, got coal face waighting distance and coal mass advanced press, which is similar to the results of theoretical calculations of Winkler foundation Composite Key Stratum; analyzed the impact of advanced press and coal mass formation to gas emission, its gas emission law is similar to the results of seepage coupled mathematical model calculations, thus validated the correctness of the thesis’theoretical analysis by field examples; On this basis, carried on optimal designing to coal face methane pre-extraction parameters, has achieved remarkable economic and social benefits.Through composite material structural mechanics theory, built Winkler foundation Composite Key Stratum model in the thesis, analyzed Key Stratum interval and advanced press in front of coal face, based on this, built coal-bed methane seepage coupled model in the influence of Composite Key Stratum, applied research results successfully in 101 fully mechanized top-coal caving face of Ting Nan coal, and carried on optimal designing to methane pre-extraction parameters in 101 fully mechanized top-coal caving face, extraction effect is remarkable, has achieved certain economic and social benefits.更多还原