Dem numerical modeling of longwall extraction of coal in “Mysłowice” colliery

The paper presents the results of the numerical DEM analysis of the extraction of coal by longwall system both with roof caving and with hydraulic backfilling. The exploitation of the most productive in the basin coal seam 510 was undertaken by the Mysłowice colliery in a very rockburst prone strata at the depth of app. 600 m. The successful extraction with backfilling of the last longwall panel in the section of the mine was a key to any other future mining activity in the area as the stress concentration and resulting rockbursts would prevent it otherwise. The deformation of boreholes measurements as well as geophysical monitoring was widely applied by the mine. The UDEC numerical model of the extensive section of the mine was built and all the extraction of coal activities ranging the period of nearly 45 years were simulated. The changes of the state of stress and strain as well as movements of the blocks in the vicinity of the longwall workings were analyzed. The strain changes in the numerical model were determined at the positions corresponding to the location of borehole measurements in-situ. The rate of advance and productivity of the longwall face turned out to be directly related to the changing geomechanical conditions just as they were determined by the numerical simulation.