Study of surface subsidence and surface water seeping due to horizontal section top coal caving(deep mining) in high steep thick coal seam

The presented paper carries out simulated calculation to study the issue of surface subsidence and the issue of surface water seeping due to repeated mining intrusion in high steep thick coal seam under complicated geological conditions, using professional simulation software FLAC. It draws a conclusion that with the increase of mining depth surface subsidence increases, its subsidence extent decreases, cranny pressed gradually on the top of the empty and finally surface water seep through the area yield in tension along the both side of the empty . Also, prediction of surface subsidence and complexion of surface seeping at different horizontal levels is made, which provides a value of guidance in in-situ production and academic research.