Stress changes and seismicity monitoring of hard coal longwall mining in high rockburst risk areas

The case study describes the control of rockburst risk by destress blasting in an example of a longwall of the Upper Silesian Coal Basin. Monitoring of stress changes and induced seismicity was implemented in the selected longwall here and a description of these techniques is given. The paper describes the natural, geomechanical, and mining conditions of the investigated locality in detail. Stress changes ahead of the advancing longwall face as well as registered induced seismicity depending on the longwall advance are analysed, including the application of the destress blasting technique. Stress release efficiency, as one goal of the destress blasting technique, is analysed according to the registered seismicity using the authors' own methodology: seismic effect calculation.