The Study Of Hydrogeological Conditions Of Fumei Three And Four Coal Mining In Dahe, Fuyuan County

Fumei Three and Four of Fuyuan Dahe coal mining area located in the northeast of Yunnan Province. The geography is more precipitous in mining area. There have more canals, and the rainfall is above normal. The coal mine lies in Gezong synclinor-ium between faults of Fuyuan-Mile and Pingguan-Agang. There are main the upper-Permian, the lower-Triassic, the middle Triassic and quaternary. And the coals are contained in the Longtan Formation and Changxing Formation. The study of hydrogeological conditions is very important because coal-lays buried deeplier, geological structure is complex in mining area and hydrogeological problems are bigger when underground mining.With the deeply study of hydrogeological conditions, I basically realize that there are more extension fractures in mining area, and most of large faults extend to the direction of NNE or almost E-W. The water flow and conten is, only more than aquifers, little in this extension fractures. The compressivetwisting faults are very difficult for groundwater to flow them, and even prevent it from flowing. Coals are, far below the local base level of erosion in mining area, buried in the siltstone, fine sandstone and pelitic siltstone. There total are 15 layers major workable coal, and most of them are included in the Longtan formation. According to the characteristic conditions of lithological association, water content, hydraulic connection of strata, etc, the rocks can be divided into 13 aquifers or aquicludes which are general alternate distribution. Most of aquifers which have close relationship with the mine water inflow content less fissure water, and has some influence on safety when coal resource is exploited underground. Especially the weak fractured aquifers of Longtan formation and Changxing formation and Kayitou formationt. Followed by karst aquifers, it is, groundwater containing moderate, mainly distributed the southeast of mining area. Because there are larger distance and some aquicludes between coal earn and karst strata, the karst water has very little impact on the future underground mining.There are four water resource for inflowing which are groundwater in crevice, surface water, abandoned mine water and precipitation. And the most of which is crevice water, hydrochemical type of HCO3—Ca, low hardness and slightly alkaline. Water flowing fractured zone of aquifer which contacts directly with the coal seam is main water conducted channel. And followed by fault fracture, caving zone and artificial channel. The mine discharge has been individually predicted, the level of elevation 550m, in this paper by the means of "Great Well", "Analogue" and "Water-Equalization". The result predicted by "Analogue" is relatively accurater. but the prediction of "Great Well" and "Water-Equalization" is more than "Analogue", as most relative error is 24.63% and absolutely one is 2265.77m3/d. The result of predictions was basically consistent on the whole of mining area, and may offer a reference for mining design or planning.Through detailed hydrogeological Working, As a result, accept:There is small size and thin Quaternary strata in mining area, and the Terrain conditions favourable to natural drainage and against the groundwater recharge. So the hydrogeological conditions of deposit belongs to simple types of the chief water filled by aquifer fracture, and it's easilier controlled.