Numerical Simulation of the Consolidation in the Presence of Sand Lenses with Time-Dependent Drainage Boundaries

Abstract

Sand lenses in clay layers may have various shapes and sizes. In many geotechnical studies, their effects are not considered carefully since detection of their positions and characteristics is difficult. In the simulation of the consolidation in clay layers with imbedded sand lenses, the problem can hardly be taken as a one-dimensional problem, and the phenomenon should be considered as a two- or three-dimensional problem. In the present study, the effect of the existence of sand lenses is investigated in terms of their positions and drainage characteristics in two-dimensional space. All drainage boundary conditions, including the boundary of lenses, are considered to be time dependent due to their variable thicknesses and permeability coefficients. A least squares based mesh free technique is used to solve the governing equations. In this method, radial basis functions are applied in function approximation. The results show the significant effect of the lenses and their characteristics in the process of dissipation of excess pore water pressure.