Study On The Mechanism And Prevention Of Water Inrush From Faults Of Floor

Water inrush from coal floor fault is an important research topic, this paper first analyzes the previous research results of fault prevention and control of water, and then integrates using theoretical analysis, numerical simulation, and engineering practice to study the theory and the methods of prevention and treatment of water inrush, draws the following important conclusions:1、Using the theoretical analysis method, through the establishment of simplified model of Fault Mechanics and semi infinite body theory of elasticity, shear stress formula is derived. By controlling variables method, giving the formula concrete numerical value, different factors under the influence of the fault plane shear stress distribution are analyzed, and then analyzed fault activation from the stress angle. Fault activation mainly concentrated in the shallow surface, the closer the distance of fault and working face, the intensifier the fault activate. Based on the theory of gradient dependent plasticity, strain and displacement formula of fault zone are derived, analyzed the different water content under the fault zone, strains and displacements, complementing the previous analysis of fault activation only from the stress angle. Based on the key stratum theory, calculation formulas of bottom water pressure are derived with or without the condition of faults. And analyzed the factors of fault dip and pressure relief area under the influence of pressure changes, improving the understanding of fault water inrush further, which is a good role in guiding production.2、The FLAC numerical simulation results show that the smaller the dip angle, the larger the plastic zone of bottom floor. The front working face damage zone is more easily to shallow development, and communicates with fault is more easily. The bigger the dip angle, the smaller the plastic zone of bottom floor. The fracture zone in front of the working face floor is easy to deep zone, at the same time the distance of fault fracture zone is far, water inrush channel is not easy to form. When the tangential stiffness is certain, the increase of stiffness of the bottom in the plastic zone expands with the increase of the fault normal stiffness, this is because the normal stiffness is greater, the higher the stress concentration of the fault zone, the larger the degree of fragmentation of rock mass, water conducting channel is also more easily formed. The dip of the fault is certain, with the increasing pressure of bottom floor, the plastic zone increases, this is because the bigger the water pressure on the bottom floor, the destruction is larger, water resisting ability of water-resisting layer is low, when the pressure reaches a certain degree, under the mining influence, the water inrush channel is formed.3、Combining with the production practice in Huaibei mining area, analyzed water prevention and control methods:mainly in Taoyuan mine as an example, take the coal pillar method.