Research on Correlation of Electromagnetic and Induced Charge of Coal-rock in Deformation and Fracture

In order to research the precursory information of coal-rock dynamic disasters, Uniaxial loading fracture experiment of composite coal-rockis is carried out in three different loading rates. The results show that there are obvious precursor signals of charge-induced and EME before the rupture of the instable coal-rock. The signals enhance gradually with the increase of the loading stress. There is a quadratic polynomial relationship between EME and charge-induced. The multiple correlation coefficient is above 0.8. The changes of charge-induced signal of the coal sample are more obvious than that of the roof and floor rock. The change rate of EME and charge-induced is almost identical to their amplitude. However, they are not completely synchronized. Although the mechanism of EME and charge-induced is quite different, each other are closely related.