【作者】 孙建；

【导师】 王连国；

【作者基本信息】 中国矿业大学 ， 工程力学， 2011， 博士

【摘要】 底板突水是承压水上采煤时,采动矿压和水压的共同作用导致煤层底板岩体变形破坏,造成大量承压水涌入采掘空间的现象,它严重威胁着煤矿的安全生产。长期以来,国内外学者在近水平及缓倾斜煤层底板的变形破坏、突水机理及突水预测等方面进行了大量的研究,取得了丰富的研究成果,对承压水上煤层的安全开采起到了重要的指导作用,但在承压水上倾斜煤层底板的变形破坏、突水机理及突水预测方面的理论研究还不够深入。因此,本文采用理论分析、数值模拟与现场监测相结合的手段,从采动矿压和水压对底板岩体共同作用的角度出发,对倾斜煤层底板的变形破坏、突水机理及突水预测进行了系统的研究,取得了如下创新性成果:(1)依据倾斜煤层上覆岩层载荷的分布特点,建立了沿煤层倾斜方向底板破坏特征力学分析模型,利用弹性力学理论结合Mohr - Coulomb(莫尔-库仑)屈服准则,推导了沿煤层倾斜方向底板岩层内任意一点的应力表达式及底板破坏深度计算公式;(2)根据倾斜煤层赋存特点,利用FLAC3D数值计算软件,建立了倾斜煤层工作面走向长壁开采三维数值计算模型,模拟分析了倾斜煤层在不同埋深、不同工作面宽度时,沿煤层倾斜方向底板岩体应力、破坏深度、破坏形态随煤层倾角变化的规律;(3)针对承压水上倾斜煤层底板所受载荷的分布特点,建立了线性增加水压作用下倾斜煤层底板隔水关键层的力学分析模型,利用弹性力学理论结合Mohr - Coulomb(莫尔-库仑)破坏准则,求解了倾斜煤层底板隔水关键层所能承受的极限水压值,推导了倾斜煤层底板突水力学判据的表达式,为现场倾斜煤层底板突水预测提供了理论依据;(4)从流固耦合的角度出发,利用FLAC3D数值计算软件,建立了承压水上倾斜煤层底板三维流固耦合数值计算模型,模拟分析了倾斜煤层工作面推进过程中,在采动矿压和水压共同作用下底板岩体的变形破坏、承压水的入侵导升及工作面底板易于突水的位置,为现场确定倾斜煤层底板突水危险区域提供了理论依据;(5)利用井下高精度微震监测技术,对桃园煤矿承压水上1066倾斜煤层工作面底板岩体进行了连续的、动态监测,结合本文提出的底板突水判据对1066工作面底板突水预测的结果,划分了底板突水危险区域,通过对底板突水危险区域进行注浆加固,成功的实现了桃园煤矿承压水上1066倾斜煤层工作面的安全高效开采。本文研究成果可为承压水上倾斜煤层的安全高效开采提供重要指导作用。该论文有图67幅,表7个,参考文献186篇。更多还原

【Abstract】 At present, water-inrush from coal seam floor is a problem that serious threatens to the safety production in coal mine. Water-inrush is a phenomenon that when mining is carried out above a confined aquifer, the combined action of mining pressure and hydraulic pressure may induce the deformation failure of coal seam floor and large confined water inrush into mining space. For a long time, many scholars have made a large number research on the deformation failure, water-inrush mechanism and water-inrush prediction of the nearly horizontal and gently inclined coal seam floor, and have achieved the comparatively abundant research achievements which perform an important directive function to the safety mining above a confined aquifer. However, the theoretical research on the deformation failure, water-inrush mechanism and water-inrush prediction of an inclined coal seam floor is not adequate, and must be investigated further. So in the present paper, from the perspective of the combined action of mining pressure and hydraulic pressure, we used theoretical analysis, numerical calculation combined with the field monitoring to systematic research on the deformation failure, water-inrush mechanism and water-inrush prediction of an inclined coal seam floor, and obtained some innovative achievements as follows:(1) According to the overburden load distribution characteristics of an inclined coal seam, we established a mechanical analysis model of coal seam floor failure characteristic along the tilted direction of coal seam, using the theory of elasticity combined with Mohr-Coulomb yield criterion, and we deduced the stress expressions at any point of floor strata along the tilted direction of coal seam and the calculation formula of floor failure depth.(2) On the basis of the occurrence features of an inclined coal seam, using the software FLAC3D, we established a three-dimensional numerical calculation model of an inclined coal seam workface with longwall mining, simulated and analyzed the distribution law of stress, failure depth and failure form of floor strata along the tilted direction of coal seam at different mining depth, different workface width and different coal seam pitch.(3) Based on the load distribution characteristics of an inclined coal seam floor above a confined aquifer, we established a mechanical analysis model of water-resisting key strata of an inclined coal seam floor with the load of linear increased hydraulic pressure, using the theory of elasticity combined with Mohr-Coulomb yield criterion, and calculated the ultimate hydraulic pressure that the water-resisting key strata of inclined coal seam floor can bear, and deduced the mechanical criterion expressions of water-inrush from an inclined coal seam floor, which can provide a theoretical basis to predict the water-inrush from an inclined coal seam floor in the field.(4) From the view of the fluid-solid coupling, using the software FLAC3D, we established a three-dimensional fluid-solid coupling numerical calculation model of an inclined coal seam floor above a confined aquifer, simulated and analyzed the deformation failure, intrusion of confined water and the location prone to water-inrush of an inclined coal seam floor under the combined action of mining pressure and hydraulic pressure, which can provide a theoretical basis to determine areas in an inclined coal seam floor prone to water-inrush in the field.(5) We used a high-precision micro-seismic monitoring technique to continuous and dynamic monitor the 1066 workface floor strata of an inclined coal seam above a confined aquifer at Taoyuan Coal Mine, and determined the areas prone to water-inrush. Combined the water-inrush prediction result obtained by the water-inrush criterion of an inclined coal seam floor, through grouting consolidation the dangerous areas prone to water-inrush, we have achieved safe and highly efficient mining of the 1066 inclined coal seam above the confined aquifer at the Taoyuan coal mine successfully.The research achievements above can provide an important directive function to the inclined coal seam safety mining above a confined aquifer.更多还原