Application conditions on acoustic emission (AE) technique monitoring coal and rock dynamic disasters in mines

The application conditions of acoustic emission technique in mines are the base of acoustic emission monitoring coal and rock and gas dynamic disasters, which must be studied before acoustic emission monitoring gas dynamic disasters in the field begins. Based on the stress wave propagation theory, quality factor Q theory, and many field tests, the acoustic emission propagation theoretic model is established, and the acoustic emission propagation laws in coal and rock with the different protodyakonov coefficient are obtained. Based on these propagation laws and monitoring techniques in the field, the application conditions of acoustic emission monitoring dynamic disasters in the coal and rock are preliminarily given, which can be described that, when the protodyakonov coefficient of coal is smaller than 0.2, acoustic emission sensors must be installed in roof rock; when the protodyakonov coefficient of hardness of coal is not less than 0.2, acoustic emission sensors can be installed in the roof rock or in the coal. These conclusions support the theoretic and testing base for the further study on the acoustic emission forecasting dynamic disasters technique.