Study On Dynamic Identification Model And Mixing Mechanism Of Mixed Gushing Water Source In Typical North China Coalfield

With the deep mining of north China type coal field,the pressure of coal floor is increasing,and the threat of mixed water gushing water source is becoming more serious,and water gushing accidents occur frequently.The hydrochemical environment of coalfield aquifer changes constantly due to coal mining,and the traditional water source identification model is difficult to accurately identify the mixed water source of coalmine.Dynamic identification of the mixed water source is a difficult problem,which needs to be solved urgently.In this paper,the typical north China type coal field,Pingdingshan coalfield as the research object,comprehensive using mathematical statistics method,numerical simulation technology,and the theory of the radioactive nuclide decay method for the hydrological geological conditions of coal mine,water chemistry,radium,radon radioactive isotope analysis,such as building a mixed coal mine water gushing water dynamic identification model of coal mixing water gushing water significantly increased recognition accuracy.The water chemical mixing process of shallow groundwater is simulated and the dynamic mixing process and mechanism of coal mine water source are analyzed.The main research results are as follows:（1）Piper trine method was used to select typical water samples from major inrush aquifers,fuzzy entropy weight method was used to calculate the constant weights of nine indexes of standard water samples(K⁺+Na⁺,Ca²⁺,Mg²⁺,Cl^-,SO₄^2-,HCO₃^-,TDS,the constant weight of total hardness and PH),and the variable weights of indexes of water samples to be judged were obtained based on the variable weight synthesis theory.Combined with the principle of membership degree,the dynamic identification model of mixed inrush water source is built to accurately identify all the water samples to be judged.（2）using Gibbs diagram to determine the control main controlling factors of shallow groundwater hydrochemistry,using typical ion ratio analysis by less water rock interaction of two groups of variables,and mixing ratio is calculated,based on the PHREEQE hybrid simulation quantitative interpretation mixing action and water rock interaction on the influence mechanism of shallow quaternary pore water chemistry.（3）Based on the decay law of radionuclides,the principle of water balance and the principle of mass conservation,the radioactive isotope distribution model of deep groundwater is constructed.The calculation results of the model show that the groundwater age of carboniferous and Cambrian limestone in coal mine is less than that of Permian sandstone groundwater.The variation mechanism and main controlling factors of radioisotope activity in main aquifers with groundwater age are explained.（4）Obtaining dynamic radium-radon nuclide data based on radioisotope distribution model.Taking groundwater age,temperature,radium,radon and other parameters as variables,combined with principal component analysis method and multiple mixing mass balance calculation method,a dynamic identification model of mixing proportion of multi-layer limestone in coal floor was constructed,and the variation of mixing proportion of water source with time and temperature and the main controlling factors were interpreted.The research results reveal the change law of dynamic mixing of upwelling water source in space and time,elaborate the mixing mechanism of coal mine water source,and put forward the high-precision dynamic identification model of coal mine mixed water source,which is of great significance to improve the safety production of coal mine.