Study on potential hydraulic connection of pit water and mine water in subsidence area of Tangshan Mine

In order to study the potential hydraulic connection between Nanhu coal mining subsidence pit water, mine water and Ordovician limestone water in Tang shan, water chemistry and isotope method were used to analyze the water samples that were collected at different locations in the research area, the water level chang es of each aquifer were contrasted by the method of water level dynamic analysis.The results showed that: the total hardness and ion content of collapse pit water, min e water and Ordovician limestone water were different greatly, the total hardness of collapse pit water was between 138.1 and 304.2 mg/L, the total hardness of mine W ater was about 600 mg/L, and Ordovician limestone water total hardness was only 30.52 mg/L; arsenic content in collapse pit water was between 0.002 and 0.004 mg/L, but the mine water and Ordovician limestone water were less than 0.001 mg/L; the hydrochemical types of collapse pit water, mine water and Ordovician limestone wate 「was different obviously; different laws were showed for milligram ( mg) equivalent percentage line chart, clustering analysis pedigree chart and Isotopic characteristics of collapse pit water, mine water and Ordovician limestone water; there was no obvious correlation of water level dynamic change between subsidence pit water and ea ch aquifer in Tangshan mining area.lt come to the conclusion that there is no direct hydraulic connection between collapse pit water, mine water and Ordovician limesto ne water. The construction of Nanhu Wetland Park has no direct influence on the exploitation of Tangshan Mine.