Stress field and energy field distribution characteristics of faults under dynamic pressure

Complex geological structures，especially the reverse fault slip instability,are the main factors that induce the impact pressure of coal mines,In order to deeply study the intrinsic relationship between the impact of rock burst disaster and fault property,the F16 thrust fault of Yima coalfield is taken as the geological background,and the influence of mining disturbance on fault activation is simulated by combining the profile of No.21921 working face of Qianqiu Coal Mine.The effects of fault drop,dip angle and mining along the upper and lower plates on the slip instability and the distribution characteristics of the stress field and energy field in the discontinuous layer of the mining face were studied.The results show that when the fault drop is small,the influence of the drop on the slip of the fault can be neglected.However,with the increase of fault drop,the normal stress increases gradually,and the tangential stress first increases and then decreases.The large drop fault is more likely to slip instability than the small drop fault; the increase of fault dip angle leads to the increase of fault slip.The normal stress increases first and then decreases,and the tangential stress decreases first and then increases.The fault dip angle is positively correlated with the fault slip instability.The working face is more likely to induce slippage or even impact ground pressure along the lower mining.The numerical simulation results show that the support pressure increases gradually before the fault passes through the fault and remains stable after crossing the fault,and it remains stable after crossing the fault.After the fault,it gradually decreases and then gradually increases.Energy accumulation in the stress concentration area of energy field in front of the working surface is obvious.Energy accumulation phenomenon in stress concentration area distributed in front of the working surface is obvious and energy accumulation area of roof is always penetrated.However，due to pressure relief,the energy reduction in the gob is more obvious,stress on the roof above the working surface is released,and instantaneous fault pressure increases sharply,and the possibility of fault activation is the greatest.