Safety analysis and prevention and control technology of thick coal seam mining under river in Xingyun coal mine
A comprehensive method including theoretical analysis,numerical simulation,observations of surface borehole flushing fluid loss and borehole television was conducted to investigate the law of overlying strata failure and water-conducting fracture development above coal seam in working face of a mine.This paper proposed the method to predict the height of water-conducting fracture zone of overbur-den rock in thick coal seam mining under river,revealed the failure form and fracture development process of overburden in thick coal seam mining,analyzed the safety of coal mining under rivers,and carried out the research and implementation comprehensive prevention and control technology for surface rivers in coal mining under rivers.The results show that the height of water-conducting fracture zone is 118.5 m and the fracture-mining ratio is 21.5 in thick coal seam mining under rivers.The height of wa-ter-conducting zone obtained by theoretical analysis and numerical simulation is consistent with the in-situ measurement results.The height of the water-conducting fracture zone show a step change,and there is a sudden increase point at each stage.The overlying strata over main roof are prone to integral fracture and subsidence after the periodic fracture of the main roof stratum,which finally shows stage stability and sudden increase.In the place where the coal seam is buried at a shallow depth,such as in the river-bed area,the development height of the water-conducting fracture zone will directly reach the surface,without waterproof safe coal rock pillar.In view of the safety problems of thick coal seam mining under rivers,the safety technical measures of coal mining under rivers are put forward,including the treatment measures of surface water,the sealing of water-conducting channels in the river-bottom,underground water control measures and other measures,which have completely removed the safety hazards of coal mining under rivers and realized the safe mining of thick coal seam under rivers.
mining under riverwater-conducting fracture zoneborehole flushing fluid lossborehole televisionwater disaster prevention and control
万方数据
维普
