Study On Seepage And Diffusion Of Rough Rock Fracture Based On Fractal Theory

There are a large number of rough and irregular fissures in the rock mass,and these fissures constitute underground seepage channels,which threaten the safety of construction and operation.The rock fissure structure has rough and irregular characteristics,and the percolation channel is composed of a single rock fissure with complex features such as cross-scale,disorder distribution,non-uniformity and anisotropy.Therefore,it is of great significance to study the rough and complex joint plane of a single fracture channel and the theoretical study of the seepage and diffusion motion of fluid in a single rough rock fissure channel.Aiming at the problem of seepage and diffusion of fluid grouting in a single fracture channel,this paper establishes a fracture channel model based on fractal theory,and conducts experimental research and numerical simulation analysis of seepage diffusion movement.The main research results are as follows:(1)A rock single fracture channel model was established.According to the fractal theory,the rock joint rough joint surface features are evaluated.The WeierstrassMandelbrot fractal function is used to establish the rock rough surface.The rock fissure channel model is constructed by the translation method.At the same time,the physical model of the single fissure channel is obtained by 3D printing technology.The influence of different tortuous joints of fractal dimension control on the cubic law is analyzed.A correction method considering the influence of fractal dimension on the cubic law of fracture is proposed.(2)The influencing factors of fluid flow state and single width flow in rough crack channel are studied through experiments.The 3D printed transparent single rock fissure channel was used to observe the diffusion motion of the fluid in the crack channel by using a constant pressure output device.The effects of pressure,gap width and fractal dimension on the single-wide flow of the rough crack channel were analyzed..(3)Consider the numerical simulation analysis of the fractal tortuous roughness of the fracture channel.The Weierstrass-Mandelbrot fractal function is used to construct the parametric surface.The convective diffusion equation is used to construct the local representation of the cubic law on the rough surface.The velocity distribution of the fluid in the fracture channel,the rough surface area of the fracture channel and the equivalent actual gap width are analyzed.The effect of features on the single wide flow of the fracture channel.By calculating the relationship between the single-wide flow and the fractal dimension,the fitted curve is obtained as a function of the cracked cubic law using the fractal dimension D correction factor.