Study On The Dynamic Changes Of Mine Water Inflow In Metal Deposits

Mine water inflow forecasting is an important index for determining the complexity of hydrogeology in mine area,and is the main basis to determine drainage equipment and water control measures.Also it is the key factor during economic and technological evaluation of deposits.However,owing to the exploration degree,generalization of the conceptual model and cognition level,the prediction results are still at the approximate level,and the prediction error of some mining areas is large.Therefore,we should focus on the prediction process of the mine water inflow,and analyze the dynamic characteristics of the mine water under the mining conditions to further improve the reliability of prediction results.By constructing different physical model with different permeability ratio,the requirement of non-continuous flow in the continuum is revealed.And the relationship between the critical hydraulic gradient and medium permeability ratio is built.Take a typical metal deposit in Anhui province as an example,based on the detailed analysis of the geological and hydrogeological conditions,the hydrogeological conceptual model and corresponding numerical model are established.In combination with ore deposit exploitation plan,considered the flow characteristics in the process of mine drainage,mine water inflow in the coal mine is forecasted.Then the change characteristics with mining time and mining level are given detailed discussion,and the comparison with analytical method is done.The results showed that the permeability ratio is the basic condition of continuous flow in the continuum,and the initial water head,the upper medium thickness less affected the phenomena of double water level.Secondly,according to change medium permeability experiment and theoretical derivation,has been clear about the exponential relationship between the critical hydraulic gradient and permeability ratio when the "double water level" phenomenon occurred.With mining activities,mine water inflow is not a fixed value,but changing with mining time and level;It decays gradually,and then tends to be stable under the safe condition of roof and floor in the deposit.In the case,three mining levels(-400 m,-450 m and-500m)of mine water discharge were stable at 3992 m~3/d,4545 m~3/d and 5140m~3/d.The results can give detailed analysis for the effect of mine drainage on surrounding water environment,and a scientific scheme for prevention and control mine water,provide reference for mine water inflow forecast in similar conditions.