Numerical simulation study on the water inrush of minor faults in coal seam floor

Based on mechanical analysis and numerical simulation, the water inrush of minor faults concealed in coal seam floor is discussed. The sliding condition of minor fault is obtained with elasticity model which is caused by the disturbance stress. And the water inrush models of minor faults are established with RFTA-FLOW^2D software. It shows that there are three stages in the process of minor fault´s water inrush, including the active stage, expanding stage and fissure transfixion stage. With the understanding of stress, damage and seepage flow evolution, the transformation of floor rock mass from water-resisting strata to inrush pathways is clearly illuminated and the groundwater inrush pathways are calibrated. Furthermore, the influence of the density of faults on the damage evolution of groundwater inrush is studied. And some significantly meaningful guides are provided for the investigation on the mechanism and prevention of minor fault´s water inrush in practice.