Numerical method for consolidation analysis of lumpy clay fillings with meshless method

Abstract

A numerical method is developed for consolidation analysis of lumpy clay fillings by using the double porosity model and the meshless method. Lumpy clay fillings consist of inter-lump voids and a clay matrix, which further consists of soil frame and pores. When a load is applied to these fillings submerged in the water, pore water pressures are generated and dissipate in the inter-lump voids and matrix. The model accounts for the coupling between the deformation of the soil skeleton and the excess pore water pressures in both the matrix and inter-lump voids, and also the fluid exchange between the inter-lump voids and matrix. The meshless method based on the radial point interpolation method (radial PIM) is used for spatial discretizations of displacement and pore water pressures. The order of interpolation function for the displacement is one order higher than that for pore water pressure to improve the numerical problem. Time domain is discretized through the backward Euler algorithm. The developed method is verified through a benchmark problem and two centrifuge tests. Finally, the effects of variations of various key parameters on the consolidation process are numerically studied for one-dimensional and plane strain (two-dimensional) problems. It is found that the developed numerical approach can successfully simulate the consolidation behavior of lumpy clay fillings despite their complex behaviour.