Vibration events in underground heading face and useful index for rock burst monitoring

Abstract

Microseismic (MS) monitoring is a prevailing monitoring method especially in the working face of coal mines to predict rock burst, but MS monitoring technology in heading face is not mature due to small disturbances and unclear monitoring indicators. Through field tests in heading face, a more accurate and effective monitoring index was obtained: the number and strength of large energy (three-channel and four-channel triggering) coal vibration events. The amplitude of the effective events can exceed the amplitude of mechanical interference signals, and can also effectively avoid uncertain interferences though multi channel result verification. The calculation method of early warning index based on the effective index is proposed, and two small geological structures are successfully predicted. The parameters, layout of MS system, monitoring index and early warning method obtained are of great significance for rock burst prevention in heading face.