Numerical Simulation Of Seepage Failure Based On Particle Flow Code

The piping and concentrated flow erosioncan cause some big damage tothe most common dam.Study on piping development cannot do without the research on soil micro structure. However, The analysis of seepage failure mainly in the piping, through the view of macro laboratory experiment, many researchers focus on physical properties of materials and stress state of piping starting and developing. Also the study on the mechanism of piping in meso-scale is based on the indirect speculations based on the results of the experiments. At home and abroad, the existing research results of the fracture concentrated seepage erosion are mostly combined with the engineering cases, in view of a kind of or limited several kind of counter filter material and the core wall soil material to carry out the indoor tests, thus carries on the analysis to the design and the effect of the crack filter healing, and about the cracks are concentrated seepage erosion numerical simulation research is relatively small. In view of this, makingthe piping and concentrated flow erosion as the research object, using particle discrete element theory based on the principle of discrete element(PFC^3D), from the point of view of mesoscopic numerical simulation, both thepiping and concentrated flow erosion meso-mechanism has been studied in this research. Through the numerical simulation of conventional three-axis model reconstruction of four kinds of fine content under the condition of the piping meso-structure relationship between the osmotic stability and fine particle content, and analyze the two aspects of qualitative and quantitative indicators based on relevant parameters, get the content of fine particles is mainly realized by changing the particle stress transfer mode of structure cohesionless soil permeability stability at the same time, from the microscopic view, by numerical reconstruction experiments show that the probability density function of particles normalized contact force P（f） and the volume weighted coordination number N_Cvol can be used for the inviscid soil seepage stability criterion, and obtained preliminary criteria: Ncvol_SV>4⁵ or Ncvol_BV>12¹4. Corresponding to the seepage stability of particle system. By simulating three different internal friction coefficient conditions. Study the boundary of crack scour process, with erosion rate and other parameters change, taking out suggestions to make hydraulic shear stress as the crack scour criterion, and the combination of granular materials in friction angle and flow velocity of crack scour development forecast cohesive soil crack scour start-up. The numerical simulation shows that it is feasible to use solid liquid coupled discrete element method to realize the concentrated seepage erosion simulation of the dam settlement crack or the non coordinated deformation joints in different zones.