| Mine discharge is the inflow water of unit time flowing into mines including all wells and exploitation systems during the process of mine production and mine construction. It is one of the key indexes to estimate the complexity of hydrogeology condition and is also the main gist of determining the drainage facilities and prophylactico-therapeutic measures of water for department of mine designing.Heshan coalfield belongs to the typical southern China's karst mineral deposit. It is located in the west side of Guangxi epsilon-type structure horseshoe-shape betwixtoland, the whole mining area is contained in the Heshan syncline. This syncline is asymmetric, steep in the east and gentleness in the west, broad in the north and narrow in the south .The axes is near the eastern coalfield. The western alar is gentleness and the dip angle increased from north to south, while the dip angle of eastern stratums are steep. The karst developed very well in Heshan syncline where the Heshan coalfield located with obviously layered in flat and zoning in vertical direction. On the base of karst development, there is a series of complex and strong underground runoffs with two large underground rivers: Nengrong and Suhe.The hydrogeology condition of coalfield has been studied deeply according to the research findings done before and field works, as well as the analysis and rearrangement for the collected data. Then the phenomenon of karst development here has been generalized, the regularity of fiat karst and vertical karst in this coalfield has been discussed, the origin of karst development has been studied deeply, at last, the karst medium of coalfield has been divided into erosion crack, strong runoff ribbon, solution cavity and gob, erosion pore, base carcass, etc.Against to the distinction of aquifer in Heshan coalfield, an improved method of generalizing complex karst water-containing mediator has been put forward. It is unpractical to generalize the complex karst water-containing mediator by the same method, while it should use different methods to generalize different karst water-containing mediator. In this way the model of generalized mediator can effective indicate the discontinuity and special aeolotropism of karst water-containing mediator. This method can also generalize the karst crack mediator to equivalent model of crack mediator, make the strong runoff into water-containing mediator which is of water-saturated, well effective porosity and high permeability. For the gob of coalfield, it have been generalized into three forms, they are water-accumulate gob hydraulic related to Honghe, not hydraulic related to Honghe and no water-accumulate gob.The practical model of three-dimensional ground water is established after some research on space structure of complex karst mediator, model of time-discrete and boundary condition of model. It realized the imitation of mine discharge in the future by Modflow program block and analogy procedure of finite difference. It calculated the mine discharge of different time slice and different exploitation levels. It need to be especially considerate for the average discharge in the year of 2010,2035 ,2040, which are 2882m3/h, 3363m3/h, 3634m3/h individually. Though the imitation of different discharge amount, the sensibility of groundwater level by the mine discharge has been studied. In this way, it provides the scientific reasons for designing drain equipment and making prophylactico-therapeutic... |
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