Study on mechanism of rock burst induced by sudden instability of fault structures

In order to study the mechanism of rock burst in the fault-influenced zone during coal mining,the influence of geological factors,such as fault inclination,tangential stiffness,lateral pressure coefficient and horizontal tectonic stress on the stress distribution and the amount of slip in the fault zone has been analyzed. In addition,the precursory information of coal burst induced by sudden fault instability has been summarized. The results show that with the increase of the dip angle,the shear stress and the amount of slip of the fault zone increases and then decreases. When the angle of the fault is 45°,they reach the peak value. The shear stress and the amount of slip of the fault zone with the increase of the tangential stiffness and the lateral pressure coefficient of the fault are increasing. Under the action of horizontal tectonic stress,when the fault is within 30 m,the shear stress on the fault plane is reduced to the lowest，When the working surface passes through the fault,the disturbance is very large,and the shear stress suddenly rises. When the distance from the fault is within 5 m，the fault slip and slip rate also exist the same law. Therefore,the suddenly rise phenomenon can be used as the precursor information of coal burst when the shear stress on the fault plane or the amount of fault slip gradually decrease in the process of coal mining.