Down-hole electromagnetic method for detecting water hazard of coal mine

Hidden trouble of water gushing at coal face always results in water gushing accidents, which will discontinue the production and even cause mine flooding and accidents with casualties. In order to ensure mining safety at the coal face, it is of great significance to find out distribution condition of hidden trouble of water gushing from the coal face in advance, and then take effective prevention and control measures. This article introduces principles, methods, technologies and application effects of several electromagnetic methods for detection of hidden trouble of water gushing at coal face, and lays emphasis on expounding method principles and effects of down-hole detections by electric transmission tomography and transient electromagnetic method. It is shown by the results of actual measurement that the mine electromagnetic method is sensitive to water-bearing low-resistivity body and can play a unique role in detecting hidden trouble of water gushing at coal face.