Size distribution of free particles in soils: a geometric modelling approach

Suffusion is a typical form of internal erosion for gravel soils in which fine particles are detached by seepage and transport by water through pores. The prediction of erodible particles can improve the assessment of the development of suffusion. The current research on the composition of erodible particles is not sufficiently detailed. The content of erodible particles cannot be accurately determined for a particular gradation. In this paper, a geometric method of generating a particle packing model is proposed. The particles are classified as free or skeleton particles depending on their coordination numbers; thus, their particle size distributions are obtained. Soils with different gradations were analysed using the proposed method. The results indicated that if the grading curve of a soil can be expressed using a fractal relationship, the gradation of free particles also satisfies an exponential function. This is useful in promoting the research on establishing accurate internal erosion criteria, evaluating the performance of filter layers, and predicting the degree of seepage failure caused by internal erosion.

Automated summary

This study investigates suffusion as a typical form of internal erosion in gravel soils, proposing a geometric method for generating a particle packing model to accurately predict erodible particles. The research found that if a soil's gradation curve can be expressed using a fractal relationship, the gradation of free particles also satisfies an exponential function, providing insights for establishing accurate internal erosion criteria.