基于离散元的裂隙岩体水沙渗流特性研究

发布时间：2018-04-12 13:56

本文选题：裂隙岩体 + 突水溃沙　；参考：《中国矿业大学》2015年硕士论文

【摘要】：我国目前煤炭资源开发重心已逐步向西部转移,而西部矿区总体具有煤层埋深浅、基岩比较薄、上覆厚风积沙的特点,易发生突水溃沙灾害,严重威胁安全生产和生态环境。因此开展裂隙岩体水沙渗流特性研究具有重要的意义。本文主要通过对裂隙岩体基本力学特性和裂隙岩体水沙渗流作用机理的研究,建立裂隙岩体水沙渗流耦合模型,数值分析裂隙岩体水沙流动特性。主要的研究工作如下:(1)裂隙岩体基本力学特性分析。基于离散元方法对裂隙岩石加载过程中应力应变特性与声发射特性之间的关系进行研究,基于摩尔库伦准则对裂隙岩体结构面的强度效应进行分析,数值模拟分析不同倾角裂隙岩石破坏情况以及不同曲线型裂隙岩石破坏过程裂隙扩展变化。研究表明,岩体强度不但取决于裂隙发育程度,还取决于裂隙面发育方向,裂隙倾角、形态的变化会对岩石整体强度产生不同影响。(2)建立裂隙岩体水沙渗流计算模型。首先对单个固体颗粒在液体中流动进行理论分析和数值模拟,得出固体沙颗粒在水中流动具有复杂的紊流状态。其次对固体颗粒相互作用机理进行分析,定义裂隙上覆松散层固体颗粒所形成的三个动态区域。最后基于平行板理论对裂隙岩体进行简化,建立裂隙岩体网络水沙渗流模型并对水沙渗流进行模拟。研究表明,裂隙岩体内部裂隙贯通性、裂隙拐角、裂隙宽度以及裂隙倾角都会对水沙渗流速率产生影响,水沙渗流过程中,固体沙颗粒以及水流对岩体的作用力与裂隙倾角和裂隙宽度有关。(3)裂隙岩体水沙渗流规律研究。在研究了上覆含水松散层压力分布特征基础上,对裂隙宽度以及裂隙倾角影响上覆松散层运动的规律进行分析。基于离散元数值方法,系统分析了岩体内部裂隙宽度、裂隙形态以及水压力对水沙渗流运动的影响规律。通过理论分析及数值模拟对溃沙过程地表漏斗动态演变规律进行研究,溃沙所形成漏斗深度及扩展半径随时间变化具有幂函数关系。
[Abstract]:At present, the development center of coal resources in China has gradually shifted to the west, and the west mining area is generally characterized by shallow coal seam, thin bedrock and thick aeolian sand overlying, which is prone to water inrush and sand collapse, which seriously threatens the safety of production and ecological environment.Therefore, it is of great significance to study the seepage characteristics of fractured rock mass.Based on the study of the basic mechanical characteristics of fractured rock mass and the mechanism of water-sediment seepage in fractured rock mass, the coupled model of water-sediment seepage in fractured rock mass is established in this paper, and the characteristics of water-sediment flow in fractured rock mass are numerically analyzed.The main research work is as follows: 1) Analysis of basic mechanical properties of fractured rock mass.Based on discrete element method, the relationship between stress-strain characteristics and acoustic emission characteristics of fractured rock during loading is studied, and the strength effect of structural plane of fractured rock mass is analyzed based on the Moore Coulomb criterion.The fracture propagation of rock with different dip angle and different curve fracture is analyzed by numerical simulation.The results show that the strength of rock mass depends not only on the degree of fracture development, but also on the development direction of fracture surface, and the variation of fracture inclination and shape will have different effects on the overall strength of rock mass.Firstly, the theoretical analysis and numerical simulation of the flow of a single solid particle in a liquid are carried out, and it is concluded that the flow of a solid sand particle in water has a complex turbulent state.Secondly, the interaction mechanism of solid particles is analyzed, and three dynamic regions formed by solid particles with loose layer on fracture are defined.Finally, based on the parallel plate theory, the fractured rock mass is simplified, and the water and sediment seepage model of the fractured rock mass network is established and simulated.The results show that the fracture penetration, crack corner, crack width and crack inclination will affect the seepage rate of water and sediment in the process of water and sediment seepage.The effect of solid sand particles and water flow on rock mass is related to crack inclination and crack width.Based on the study of the pressure distribution characteristics of the overlying water-bearing loose layer, the law of the influence of crack width and crack dip angle on the movement of the overlying loose layer is analyzed.Based on discrete element numerical method, the influence of fracture width, fracture shape and water pressure on seepage movement in rock mass is systematically analyzed.Through theoretical analysis and numerical simulation, the dynamic evolution of the surface funnel in the process of sand collapse is studied. The variation of the funnel depth and the spreading radius with time has a power function relationship.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD313

【参考文献】