Numerical modelling of internal erosion process in gravel soils based on the percolation analytical method

Abstract

Internal erosion is a common form of damage in geomaterial structures that is caused by the migration of soil particles under a seepage flow. The geometrical characteristics of soil particles is regarded as the intrinsic factor for internal instability; thus, in this study, a network modelling technique is formulated for this purpose. The soil particles and pores are generalised into a network model according to their fractal gradations; thereafter, the percolation theory is applied to analyse this conceptual probabilistic model. The percolation and erosion backbones are simulated in the direct square bond percolation model through the extended Hoshen–Kopelman algorithm and direct electrifying algorithm. Monte Carlo experiments are conducted to analyse the internal erosion process in this network model. The extent of internal instability can be calculated quantitatively, and the deposition rate of transported particles in the mass conservation equation can be evaluated for further analysis. Compared with internal erosion tests, the percolation analytical method is in accordance with experimental results. This method provides fresh insights on the nature of internal erosion from a statistical perspective.