Study on optimization of mine water inflow calculation methods in different production periods

There were numerous methods to calculate the mine water inflow rate, and each method has its application limitation. In order to choose a reasonable and accurate calculation method of water inflow in different stages of mine service life,six coal mines which located in northern part of Datong coalfield including Tashan, Dongzhouyao, Majiliang, Yanzishan, Sitai and Tongxi mines are taken as research examples. The hydro-geological comparison method, correlation analysis method and analytical method with easy-to-collect parameters and easy-to-understand calculations were selected to calculate the water inflow from each mine. The research results show that: ①In the mine exploration stage, there is no measured water inflow data in the field,and hydro-geological parameters have not yet been determined. But using hydro-geological analogy method to make predictions by using water inflow data from adjacent mines in the same mining area can improve prediction accuracy;②During the mine design and infrastructure construction stage, the mine water inflow volume is calculated to serve the construction of the shaft and the roadway.Such as Majiliang Mine,the relative error of the analytical method to calculate the water inflow volume is only 19.77% and the relative error of the hydro-geological analogy method is 36.20%. Therefore, the calculation of water inflow at this stage is suitable to use the analytical method to predict the hydro-geological parameters found in the proposed well-bore and the first mining area;③Yanzishan Mine is a trial production mine, the relative error of the calculation method is 3.56%, and the relative error calculated by the analytical method reaches more than 28%. So the correlation analysis method, is more reliable to predict the mine water inflow.④Both Tashan Mine and Tongxin Mine have reached production. Through comparative analysis, the relative errors of mine water inflow volume calculated using the hydro-geological analogy method are within 20%. Therefore, in stable production stage, the hydro-geological analogy method using the water-rich coefficient per ton of coal is simple and clear, and the prediction accuracy is also high.