Non-Darcy Flow Model For Water-Inrush In Mine And Its Initial Application

Waer-inrush is one of the major disasters to the mine safety production.Generally,the high-speed non-Darcy flow and the unity of dynamic flow field are the two principal properties of the water-inrush in mines.In this paper,a non-Darcy flow model for water inrush in mines has been established based on the conservation of mass and the pressure equilibrium principle.The corresponding model has a coupled relation of Darcy equation,Forchheimer equation and Navier-Stokes equation,which builds the connection of water source in aquifer,water-inrush channel and the exit of tunnel in a uniform flow field.Furthermore,a numerical method which combines the finite-element and finite-volume has been presented.Based on the software of Finite Element Program Generator(FEPG),the FORTRAN source program is compiled and used for simulating the complete flowing process of water inrush.The main research works and conclusions are summed up as followed.Based on the assumption that nomatter in situ or accumulation of fractured rock mass,when water-inrush occurs the channel of water-inrush has been formed and the permeability coefficient of ractured rock mass is several orders of magnitude than surrounding rock.The corresponding model has a coupled relation of Darcy equation,Forchheimer equation and Navier-Stokes equation,which builds the connection of water source in aquifer,water-inrush channel and the exit of tunnel in a uniform flow field.Furthermore,based on the software of FEPG a numerical method which combines the finite-element and finite-volume has been presented.Seepage mechanism of water-inrush in mines has been studied,the study found that is not realistic with linear theory predicts the amount of water size and analyzes the potential degree of disaster for water inrush,.Taking the case of water-inrush on 704 working face of Yi An,then the non-Darcy flow model of Yi An for water inrush in mines has been established.By comparison of the two different calculation results for Darcy and non-Darcy flow model,the necessary of adopting non-Darcy model for water-inrush in mines is explained.It is also found that the fractured rock mass is the channel that connects the confined aquifer and tunnel,and the inertia effect of the high-speed flow in the channel is the main cause that leads to the water-inrush through the fractured rock mass,but the roadway turbulence phenomenon is the spatial response of inertia force dominant,ignoring the inertia of the fluid will cause a big deviation.