Sensing Roof Conditions ahead of a Longwall Mining using the Shearer as a Seismic Source

There has been a requirement for technologies that are capable of imaging the rock conditions in mining, ahead of the working face and without any interruption to the production. A seismic tomography experiment was carried out at a coal mine in order to prove the concept of using the continuous coal cutter (shearer) as a source for mapping rock conditions ahead of mining. The results have shown that the shearer generated strong seismic energy that can be adequately detected by geophones deployed as far as 300 m from the source and along the gateroads. It is demonstrated that the seismic arrival times associated with the shearer cutting can be reliably determined using noise filtering and signal cross-correlation techniques. This enables reliable seismic tomograms of the roof rock conditions to be obtained in real-time while mining is in progress.