Comparative Study On Prediction Methods Of Mine Water Inflow In Dulong Mining Area, Wenshan, Yunnan

At present,the pit water inflow forecast mainly uses a variety of methods to directly calculate the water inrush in the pit in the future mining state,and finally the maximum value,median value or average value in the calculated value is the prediction result method.The accuracy of the influx prediction results obtained in this way is low.In order to improve the accuracy of the prediction,it is necessary to select an appropriate calculation method and calculation result processing method.This thesis relies on the project of"Special Engineering Geology Research of Dulong Open-pit Stope of Yunnan Hualian Zinc-Indium Co.,Ltd.",taking Dulong mining area as the research object,through geological mapping,drilling and water injection test,groundwater dynamic monitoring,hydrochemical analysis Other means to identify the hydrogeological conditions of the mining area,on this basis to carry out mine pit water forecast and other theoretical studies,and achieved the following results:(1)The degree of fissure development can be used to characterize the permeability tensor,and the linear relationship between the permeability tensor ellipsoid is:Ky=0.7498Kx,Kz=0.1089Kx.(2)The fracture permeability coefficient K₂ and test permeability coefficient K₁ were calculated from the fracture and pumping water test data,respectively,and the substitutability of K₂ to K₁ was compared and analyzed.The substitutability of K₂ for K₁ is mainly affected by the type of aquifer and the number of fracture calculation groups N:For fractured water aquifers,when the number of fracture groups N is sufficient(N?60 in this study area),K₁ and K₂ They are equivalent in size,and K₂ can be used in place of K₁ for corresponding calculation and research.For karst water aquifers,there is no obvious relationship between the two and they cannot be replaced by each other.(3)Four methods including water balance method,large well method,three-dimensional flow numerical method and two-dimensional flow numerical method are used to calculate the water inflow in the current mining state of the pit(910m platform),and compare it with the measured data.The results show that the water inflow calculation result of the three-dimensional flow numerical method is the closest,the relative error?is 5.07%,and the rest are the two-dimensional flow numerical method,the water balance method and the big well method,and the?is 14.37%,29.34%and 50.61%respectively.Therefore,the calculation result of the three-dimensional flow numerical method in this study area is more accurate,and the prediction result of the pit water inflow of the 760m platform with this method is 38979.84m³/d.