USING ELASTIC WAVE VELOCITY ANOMALY TO PREDICT ROCKBURST HAZARD IN COAL MINES

For the prevention and control of rockburst in underground coal mines, a detailed assessment of a rockburst hazard area is crucial. In this study, the dependence between stress and elastic wave velocity of axially-loaded coal and rock samples was tested in a laboratory. The results show that P-wave velocity in coal and rock is positively related to axial stress and can be expressed by a power function. The relationship showed that high stress and a potential rockburst area in coal mines can be determined by the elastic wave velocity anomaly assessment with passive seismic velocity tomography. The principle and implementation procedure of passive seismic velocity tomography for elastic wave velocity were introduced, and the assessment model of rockburst hazard using elastic wave velocity anomaly was built. A case study of a deep longwall panel affected by rockbursts was introduced to demonstrate the effectiveness of tomography. The rockburst prediction results by passive velocity tomography closely match the dynamic phenomenon in the field, which indicates the feasibility of elastic wave velocity anomaly for rockburst hazard prediction in coal mines.