Abstract: By means of theoretical analysis and field observation, the occurrence cause of rock burst in dip coal pillar area of extra-thick coal seam, and the real-time monitoring and early warning technology were studied in this paper. The results show that the strata structure of dip pillar area and the asymmetric I-shaped spatial strata structure formed by excavation are primary causes of abnormal stress concentration. By establishing spatial strata structure model and strike abutment pressure calculation model in the dip pillar area, the stress distribution law of the overlying strata in the pillar area was obtained. It is revealed that the stress distribution area movement and value variation are the main causes of rock burst in the dip roadway near the coal pillar. In addition, the integrated monitoring and early warning of rock burst in dip coal pillar area were proposed, that is, the strata fracturing and movement were monitored by microseismic system, and the risk region of rock burst was predicted by index of microseismic momentum, while the risk level of rock burst was further predicted by borehole stress maters. Thus, the monitoring and pre-warning system of “regional monitoring and prediction and local monitoring and early warning” were established. The research achievements were applied to the dip coal pillar area of No.21 mining district, Qianqiu coal mine successfully.

Key words: extra-thick coal seam, district dip, coal pillar, rock burst, monitoring and early warning