Research on Mechanism of Fault Rock Burst

In order to obtain the mechanism of fault rock burst occurred, taking F16 fault in Yima mining area as a study object, this paper used analog simulation a nd numerical simulation method. The process of fault rock burst induced by mining disturbance was researched and a sensitivity index of fault slip was proposed. The r eason of fault rock burst was revealed. The results showed that according to mining disturbance degree, fault rock burst contains three stages which were start of fault activation, fault intense activation and fault impact. The ratio of shear stress and normal stress could connect fault stress field and fault activity, the ratio was sensitive i ndicator of fawt slip instabilty.When the stress ratio was low, sliding velocity was almost zero. When the ratio rised, sliding speed began to wave and increased graduall y.When the ratio reached at maximum, the fault sliding instability, sliding velocity mutations and fault rock burst occurred. The overlying strata destruction caused by mi ning was the direct cause of fault rock burst and its root cause was changed of fault stress field.