Influence of parameters of a fault on coal mining above a confining aquifer

According to the theory of coupling of solid and fluid,the influence of fault step and dip angle on the stresses and deformations of coal layer and confining rock along with the pressure of pore water are numerically simulated by finite element method during the process of excavation above a confined aquifer.The mechanism of water inrush and the potential point of water inrush are explored.The distance of coal column for preventing water inrush is also analyzed quantitatively.The research results indicate that (1) fault-failure-type water inrush occurs more often than floor-failure-type water inrush under the existence of normal fault;(2) the influence of fault step and dip angle on the feature and position of water inrush is not evident,and water inrush may occur at both coal layer and the floor near working face;(3) the distance of coal column for preventing water inrush should be increased with the increase of fault step and dip angle.It is helpful in practical design of water inrush in coal mining.