Abstract: In order to study the relationship between impact tendency and charge induction of fracturing coal, uniaixial compression tests were performed by using a self-developed multi-channel system. The distribution of charge signals and other parameters were analyzed qualitatively and quantitatively for coal samples different in impact tendency. The experimental results show that the change of stress-charge in the process of fracture is consistent, that the charge signals are stable at the initial stage of loading and they change remarkably in the stage of stress drop, that charge signals vary with the impact tendency, that signals of strong impact occur before the stress peak and the weak occurs before and after the stress peak, that signals of samples without impact tendency are generated mainly in the softening stage after the stress peak, that the stronger the impact tendency of coal is, the less accumulative charges are after the stress peak, and the bigger the quantity of the charges per unit time will be, and that impact tendency can be predicted by analyzing distribution of the charge signals and the relative parameters to give a basis for predicting the dynamic disaster of rock burst.

Key words: electric charge induction, bump proneness, rockburst, uniaxial compression, unstable fracture