【作者】 赵忠明；

【导师】 李德海；

【作者基本信息】 河南理工大学 ， 采矿工程， 2011， 博士

【摘要】 本文以小浪底水库淹没区附近的新安矿区采空区为实验背景。研究采空区遭受库水的浸泡、冲掏和溶蚀条件下引起的上覆岩层的稳定性以及地表移动变形破坏规律。在对库区煤岩进行饱水状态下的物理力学性质测定后,得出围岩在饱水状态的物理力学参数及不同含水率煤样的抗剪强度与垂直应力关系曲线,为库区采空区相似模拟试验及数值分析提供数据支持。相似材料模拟实验以新安县王家沟村的一处采空区为原型条件,研发了液力模拟煤层开采系统来模拟不同采区尺寸上覆岩层的移动变形规律,以及由于采空区经受反复的水流冲掏和溶蚀,致使采空区侧壁及煤柱的细粒物质被冲刷带走情况下,引起采空区围岩的二次活化。为了精确地观测位移,采用了普通数码照相技术,开发了细微形变位移分析软件CPAnalysis,进行数据采集后的处理。运用分形几何理论,分析采空区“三带”在初次顶板垮落以及二次顶板围岩活化条件下,岩体裂隙发育的差异,建立了覆岩下沉系数与上覆岩层分形维数的相关关系。运用数值模拟方法研究了王家沟采空区覆岩的稳定性。根据王家沟的地面地形地貌和地下采空区的赋存条件,利用FLAC3D自定义函数功能,建立了三维立体计算模型。模拟小浪底库区蓄水前后覆岩和地表的移动过程,得到了采空区在渗流作用下岩层的移动变形规律。基于尖点突变理论,分析了不同形式下的采空区的稳定性及采空区失稳时能量的释放机制,对小浪底库区采空区进行分类,将狭窄煤(岩)柱支撑的采空区简化为非对称开采时的力学模型,将采空区跨度几乎相等且有狭窄煤(岩)柱支撑的采空区简化为对称开采时的力学模型。对于留有宽煤柱支撑的采空区,将其简化为条带开采时的力学模型。将模型顶板、煤柱、底板看成一个系统,在简化采空区的基础上,引入了水致弱化函数,研究了在库水渗透及软化作用下的采空区稳定性。更多还原

【Abstract】 In this thesis, the mined-out areas of Xin’an mine, around the flood areas of the Xiaolangdi reservoir was considered the background for our model. The stability of overlying strata influenced by mined-out areas under dipping, scouring and dissolution by the reservoir water, and the laws of face movement & deformation and destruction were studied.After testing the mechanical characteristics of coal and rock in saturation within the reservoir area, the mechanical parameters of surrounding rock in saturation, and the relation curves between shear strength of coal samples with various water contents and vertical stress were obtained, which provided data for the similar material simulation and numerical analysis of mined-out areas in the reservoir area.Considering a mined-out area in wangjiagou village of Xin’an County to be the prototypical condition, the similar material simulation has developed a hydrodynamic simulating coal-seam mining system to simulate the laws of movement & deformation of overlying strata with different mining scales, and the surrounding rock reactivation of the mined-out area, which would take place when the mined-out area was under scouring and dissolution repeatedly, and the granules from sidewall and safety pillar were washed away. To achieve accurate displacement observation, the digital camera was used, and a fine deformation displacement analyzing software (named CPAnalysis) was developed to do processing work after data collection. The fractal geometry theory was applied to analyze the rock fracture developing differences of the three-zone in goaf after the first roof collapse, as well as in the second activation of roof surrounding rock. Moreover, the correlative relationship between the subsidence coefficient and fractal dimensions of overlying strata was established.The stability of overlying strata in the mined-out areas in wangjiagou village was studied by numerical simulation. Based on the face topography and accumulation conditions of the underground mined-out areas in wangjiagou village, using the automatic defined functions of FLAC3D, a 3D calculating model was set up. The movement of both overlying strata and surface before and after impounding was simulated, and the strata movement & deformation laws of mined-out areas under seepage were acquired.Based on the cusp catastrophe theory, the stability of mined-out areas in various forms and energy release mechanism when the stability was losing were analyzed. The mined-out areas close to the xiaolangdi reservoir area were assorted. The ones supported by narrow coal (rock) pillars were simplified into mechanics model in dissymmetric mining. While the ones whose spans were almost equal and also supported by narrow coal (rock) pillars were simplified into mechanics model in symmetric mining. Besides, the ones with broad coal pillar supports were simplified into mechanics model in strip-pillar mining. Based on simplified mined-out areas considering the roof, coal pillar and bottom of the model as a system, and bring in water weakening functions, the stability of mined-out areas under penetration and softening effect was studied.更多还原