Discrimination of mine water-inflow sources based on the multivariate mixed model and fuzzy comprehensive evaluation

The accurate discrimination of the mine water-inflow sources is one of the main focuses of mine hydrogeological work and represents the basis of coal mine water hazard prevention. To accurately discriminate the water-inflow source in the – 700-m air return tunnel of the Longgu Coal Mine, firstly, according to the water-inflow conditions of the coal mine, three water sources were preliminarily estimated: the Ordovician limestone aquifer, the No. 3 limestone aquifer, and the sandstone aquifer in the roof and floor of No. 3 coal seam. A number of water samples were then selected from each of the three aquifers as the standard comparison water samples. A sample of water inflow from the tunnel of the coal mine and nearby locations was selected as the water sample to be tested. Six conventional hydrochemical indexes (Na + + K + , Ca 2+ , Mg 2+ , Cl − , SO 4 2− , and HCO 3 − ) in the water sample to be tested and standard water sample were tested and discriminated by the multivariate mixed model and fuzzy comprehensive evaluation. The results show that the water-inflow source in the –n700-m air return tunnel is the Ordovician limestone aquifer, and a hydraulic connection was observed between the No. 3 limestone aquifer and the Ordovician limestone aquifer. The findings provide data support for the management of the water-inflow process in the Longgu Coal Mine, and have practical guiding significance for the discriminating water sources in other coal mines affected by water hazards.