Research on the Effect of Dip Angle on Shear Stress on Normal Fault Plane and Water Inrush in Floor Strata During Mining Activities

Abstract

This paper presents an investigation on the characteristics of shear stress on normal fault plane by employing the mechanical model and the characteristics of water inrush from floor strata during mining activities by employing numerical model. The shear stress formula on fault plane is obtained by using the solution of a homogeneous half-plane affected by normally distributed forces in the theory of elasticity. The mechanical model shows the variation of shear stress on fault plane with different dip angle and fault reactivation is analyzed according to the shear stress. Based on these, the fracture distribution and seepage distribution on floor strata are numerically simulated by using the RFPA2D-Flow software, and the effect of dip angle on water inrush from floor strata is discussed. These results indicate that the smaller value of dip angle is easier to be reactivated and to produce connecting fractures between floor strata and normal fault comparing with the larger value of dip angle, which provide significant insights into remaining coal pillar with similar geological conditions.