Key technology of water inrush prevention and control in coal mining face under condition of complicated structure

The minefield with the structure in Shouwang Mine was complicated,the No.2 mining block in No.2 seam was both threatened by the floor pressures from Taiyuan Formation limestone and Ordovician limestone water (Double Water Pressures). In order to solve the safety mining under the double water pressures in No.2 mining block of No.2 seam,the drilling exploration and comprehensive geophysical exploration means were applied to find out the hydrogeological features and water rich distribution features of the aquifers in Taiyuan Formation limestone and Ordovician limestone and water conductivity of structure. A study was conducted on the floor failure law of the coal mining face in No.2 seam. The simulation and calculation conducted with the fluid-solid coupling numerical showed that the max failure depth of the floor in the coal mining face designed was about 21 m. The water inrush coefficient method was applied to evaluate the safety mining under the double water pressures. The comprehensive effective prevention and control measures were provided to the safety mining with the double water pressures. The study results showed that the aquifers in Taiyuan Formation limestone and Ordovician limestone of No.2 mining block in No.2 seam would have high abundant water and a hydraulic connection. It was the key of the water inrush comprehensive prevention work of double water pressures that high water inrush hidden dangers existed in Taiyuan Formation limestone of the North-East area of the mining block and the water conducted fault. Therefore the “exploration-evaluation-prevention” technical system formed could well solve the key problem of double water pressure water inrush comprehensive prevention in No.2 mining block.