The Effect on Seepage through Embankment Dams by the Nonlinear and Anisotropic Characteristics of Permeability

Abstract

In order to take the nonlinear and anisotropic characteristics of permeability into account, technique of fictitious coefficient of permeability was utilized. 36 calculations on miscellaneous conditions were made by FEM. These calculations used relationships between hydraulic gradient and discharge velocity by experiments. The relationships between hydraulic gradient and discharge velocity showed the non?linearity (that is, non-Darcy relationship) and the anisotropy.
Except for the isotropic, non-Darcy and low hydraulic gradient flow condition in which the hydraulic gradient-vertical discharge velocity relationship by an experiment was used for calculation in both of horizontal direction and vertical one, those calculations gave reasonable results. In the exceptional condition, the calculation could not give appreciable result because the hydraulic gradient-discharge velocity relationship provided very low velocity but high threshold gradient.