Analyses of upper limit of coal mining under Yushe river

Yushe river through the Yushe coal field from northwest to southeast,transversely through the coal seam,affects coal mining under rive.The authors explored in situ,analyzed the hydrological condition and the lithology of upper rocks and forecasted the height of the water conductive fractured zone.To different upper limits of coal mining under river,authors numerically simulat-ed the change of underwater flow field surrounding the river,and forecasted the inflow of water in coal mine,and fix on appropriate upper limit of coal mining under the river,and partitioned the safe mining area under the river.According to that the safety mining areas are limited with a distance of 100 m away from river bands or in area where with distance 100 m near the bands or under riv-er but the perpendicalar distance between coal seam and river is over 260 m.