The Study Of The Hydrogeological Features Of Ningtiaota Coal Mine

The mine of Ningtiaota is located in30kilometers northwest away from the city ofShenmu County, YuLin City, ShanXi Province. The construction of the coal mine began in2005, and trial production started in2009. North limb of the mine has mining multiplecoalface including1-2and2-2coal seam, but in May2011, the first S1210coalface in thenumber2-2coal seam in south limb of the mine stopped mining for the water inrush, whichforced production areas moved to north of south limb.In this paper, by analyzing and researching mass date during geological exploration andproduction, it was found that condition of groundwater runoff loop is good, the overallgroundwater flow from west to northeast, to east and to southeast; The geologic structure ismonoclinic to west and no fault development in it; The mine has multiple water filling source,groundwater link conditions are well. Precipitation is the main source of the supply of surfacewater and groundwater; Surface water including Miao ditch, Kaokaowusu ditch, Ken Tielingditch, LuCao ditch and some seasonal channeling. Surface water and aquifer water has directlink of supply and drainage by rock fracture. Water in valleys area can flow into the minethrough mining fissure; The mine water filling aquifers existed with overlying sandstone ofcoal seam and the loose bed aquifer. The main water filling source of the mine are weatheredbedrock fractured confined aquifer of Zhiluo Formation and sandstone confined aquifer ofYanan Formation, especially in the south limb, they are also the straight water-filling aquifersfor the2-2coal seam; Along the sides of Kaokaowusu ditch, small mines leaved some goaf in2-2and3-1coal seam and hydrops have effects on the mine production; In the east of miningfield, the mining activities will also be affected by the burnt rocks water.The main water fillingchannel of the mine is crack zone made by mining, in the central field area where originalplanned strip mining have many not closed drilling which are also mine filling water channels.The north and the south limb of geomorphic types exist obvious differences in mine.Landform of north limb is mainly loess area, infiltration rate of atmospheric precipitation is small, landform of south limb is mainly sand covered area, which is conducive to theinfiltration of precipitation; Mine hydrogeological conditions in the north limb is relativelysimple, and it’s water inflow is generally200m3/h; Mine hydrogeological conditions in thesouth limb is complex, aquifer recharge and water-rich are better, the water inflow is generally400m3/h.When S1210coalface mining pushed taken to61m from the cut in south limb, themaximum amount of water taken place up1157.0m3/h of water inrush. The reason of waterinrush is roof caving happened after initial pressure, water flowing fractured zonecommunicates confined aquifer of the upper weathered bedrock fissure and other watersources; In this paper, The water inflow of mine S1210coalface has been sectionally simulatedand predicted by Visual Modflow and Great-well method, it is suggested to restart cut at1700m of S1210coalface to north and forecast that the normal water inflow of S1210in1700~6000m coalface is862m3/h, the maximum water inflow was1293m3/h. In view of theactual situation of mine, this paper put forward that production should avoiding the floodwater area and be arranged in the north of south limb where hydrogeological condition isrelatively simple.