Dynamic Calculation Method And Application Of Mine Water Inflow Based On Hydrogeological Parameter Evolution

In the process of coal mining,in order to prevent the occurrence of water inrush disasters,it is particularly important to carry out water inrush prediction,especially the accurate prediction of mine water inflow.In this thesis,the analytical method(also known as ’Virtual Large Diameter Well Method’)which is widely used in the prediction of mine water inflow is taken as an example,and the relevant results accumulated in the previous period of our research group was further excavated,and comprehensively analyze the errors and defects of the traditional ’Virtual Large Diameter Well Method’in predicting water inflow,then carry out the exploration research and application verification of the dynamic calculation method of mine water inflow based on the evolution of hydrogeological parameters.The main research results obtained in this thesis are as follows:(1)The hydrogeological effect and the dynamic evolution law of parameters in the process of mining panel are revealed.On the basis of the related research work of the typical mining areas in the eastern and western regions carried out by our research group in recent years,and through deep mining and comprehensive research,the hydrogeological effect and water inflow characteristics induced by mining failure of roof strata in the process of mining panel are clarified,and the dynamic evolution law of key hydrogeological parameters such as permeability coefficient,influence radius and water level drawdown and its influence on roof water inflow are revealed.(2)Based on the evolution of hydrogeological parameters,the principle and method of dynamic calculation of mine water inflow by ’Dynamic Virtual Large Diameter Well Method’ are proposed.The theoretical model of the parameters such as the center position and the influence radius of the ’dynamic virtual large diameter well’are constructed.The determination methods of the key hydrogeological parameters such as the radius of the horizontal well,the drawdown of the vertical stage and the permeability coefficient of the disturbance range in the calculation of the ’Dynamic Virtual Large Diameter Well Method’ are proposed.The dynamic calculation formulas of the disturbed flow field under different stages of the dynamic evolution process are preliminarily deduced.The numerical model for the dynamic calculation of mine water inflow based on the evolution of hydrogeological parameters is constructed.The simulation demonstrates and confirms the continuous dynamic evolution process of the center position,influence radius and groundwater flow field of the ’dynamic virtual large diameter well’ with different advancing distances of the mining panel.(3)The reliability evaluation and error analysis of the dynamic calculation results of mine water inflow under different variable parameters in typical mining areas are carried out.The theoretical calculation and reliability verification of mine water inflow under different variable parameters in the process of typical mining areas in the east and west are carried out.The verification results show that the calculation accuracy of the ’Dynamic Virtual Large Diameter Well Method’ is obviously better than that of the traditional ’Virtual Large Diameter Well Method’,especially under the condition of double parameter variation,the relative error of the settlement results of the ’Dynamic Virtual Large Diameter Well Method’ can be reduced by 243 % and 92.4 % respectively compared with the calculation results of the traditional ’Virtual Large Diameter Well Method’ in the eastern and western typical mining areas,and the minimum relative error can reach 9.1 % compared with the measured water inflow.The exploratory research results of this thesis can lay a certain method foundation for the dynamic and accurate calculation of mine water inflow and the deduction of interference flow field evolution in the long-term mining process.There are 44 figures,12 tables and 121 references in this thesis.