An experimental study of the electromagnetic emission during the deformation and fracture of coal or rock

Experiments of electromagnetic emission (EME) during the coal deformation a nd fracture have been conducted. Its regularity is studied, and the mechani sm is discussed and analyzed. It is proved that EME can be produced during the deformation and fracture of coal; EME and acoustic emission (AE) are no t strictly synchronous; EME signals are more than AE signals, and closely r elated to the deformation and fracture of coal or rock. EME can be used to discover the deformation and fracture mechanism of coal or rock and forecas t the earthquake, catastrophic dynamical phenomena of coal or rock in mine and the building stability of rock and concrete.