Influence Analysis of Discrete Element Model Parameters in Seepage Erosion Simulation

Abstract

[Objective] Due to the hidden nature of seepage erosion occurring in engineering and the complexity of its development, discrete element simulation has become an important tool for scholars to carry out research on seepage erosion mechanisms.The parametric construction of the solid model influences the transport and loss of particles under water flow by controlling the filling and distribution of particles within the model, and is a key component in carrying out discrete elemental simulations of seepage erosion. [Methods] The current research on discrete element model parameters is mainly a single-parameter discussion. In this paper, from the three dimensions of soil pore space, soil particles and wall sidewalls, six sets of soil models are constructed by considering the changes of porosity, particle overlap ratio and wall modulus, and upward seepage calculations are carried out to record the internal particle loss process, the structural change of the force chain, and the change of the porosity process, in order to evaluate the influence of the three parameters on the model. The influence mechanism of the discrete element model parameters on the seepage and erosion process was also analyzed from a fine-grained point of view. [Results] Discrete element model parameters affect the stage of particle loss under water flow by influencing the composition of particles and force chains within the model. Initial porosity controls the number of particles filling the interior of the model; wall modulus and particle overlap ratio affect the number of contacts within the model. Models with a high number of particles and contacts have internal particles that tend to move as clusters of particles; conversely, free fine particles that do not form contacts undergo longitudinal migration as single particles within the model, and the porosity profile shows fluctuating changes. [Conclusion] In this study, the effect of parameters on the model is described from a fine-grained point of view, with a view to providing a theoretical reference for the use of discrete element simulation methods based on the fluid-structure coupling theory.

Keywords

• seepage erosion
• discrete element simulation
• intermittent graded soil
• loss of fine particles