Study On Water Inflow Prediction And Risk Response Of Typical Coal Mine In Arid Area Of Northwest China

As the main energy source in China,coal plays an irreplaceable role in the national economy.However,coal mine water accidents frequently appear in the process of mine production,which seriously threatens the safety of coal mine production.In order to ensure safe production of coal mine,this paper takes the sea coal mine,na Lin no.2 coal mine as a typical mining area,the northwest arid area based on groundwater dynamics,special hydrogeology theory,through the collection of data,high precision geophysical field experiment,the field of hydrogeology and indoor parameters estimation,the simulation field water level series test,numerical simulation method and means,such as dynamic prediction the sea mines and na Lin no.2 coal mine mining water inflow;Flood accidents that may occur on the way of mine production and risk avoidance measures are analyzed and put forward.It provides scientific basis for mining coal resources and safety production.The conclusions are as follows:(1)Based on the hydrogeological borehole data and field geophysical exploration tests in the study area,the strata are reasonably generalized according to the lithology and water-proof properties of the strata.Daize coal mine and Nalinhe No.2 coal mine are generalized into 9 strata,and the direct and indirect water sources of coal seams are determined.(2)in the sea is mine and na Lin no.2 coal mine,the numerical simulation model is set up,in the study area by identifying the model validation phase and water balance analysis,the results show that the numerical model is successful and hydrogeological parameters after tuning parameter is consistent with the actual conditions,the numerical model to simulate the hydrological geological entity model can replace the actual hydrogeological structure.(3)Using numerical method,large well method and water collecting corridor method,the water inflow prediction and research are carried out respectively for Daize Coal Mine and Nalinhe No.2 Coal Mine.Through the prediction results of water inflow,various forecasting methods are mutually verified to a certain extent.Because the coal mining is in the state of continuous tunneling,the large well method and the water collecting corridor method can only be used as the reference basis,and the prediction of the water inflow in the coal mine is still subject to the numerical method.(4)The precise subdivision of strata and aquifer system through the fusion of geophysical and drilling data can effectively improve the accuracy of numerical simulation calculation of water inflow,which can reach more than 8%.(5)Based on the uncertainty analysis of mathematical statistics,the correlation analysis and significance test were conducted on the amount of drainage water and precipitation,evaporation,air temperature and raw coal output in Nalinhe No.2 mining area.Through calculation,the actual value was fitted with the calculated value,and the fitting effect was general.After repeated trial calculation and analysis,the correlation analysis and significance test were conducted again when the raw coal output was taken as the boundary.The results showed that the prediction effect of the drainage water quantity combined with meteorological factors was better than that of the overall prediction directly,and the correlation coefficient increased by about 0.15.(6)Based on the uncertainty analysis of the numerical model,Nalinhe No.2 Coal Mine is taken as the research object,and the influencing factors are the permeability coefficient and the water storage coefficient.Through changing the influence factors to different degrees,the predicted value of the water inflow shows that changing the permeability coefficient is greater than changing the water storage coefficient.When the change rate of groundwater level is taken as the benchmark,the change of water storage coefficient causes the change of groundwater level to be faster.When the change of water inflow is taken as the benchmark,the change of permeability coefficient causes a greater change of water inflow.In this paper,the permeability coefficient is considered to be the key factor affecting the change of groundwater inflow.(7)For the study of mine water inrush accidents that may be caused by mining,this paper uses the method of water inrush coefficient to carry out the early warning and prediction of water inrush accidents.The results show that: in Dahai coal mine,water inrush accidents are prone to occur when the water pressure is greater than 3.96 MPa,and vice versa;For Nalinhe No.2 Coal Mine,when the water pressure is greater than 3.47 MPa,water inrush accident is likely to occur,and vice versa.