HYSTERESIS OF FLUX‐GRADIENT RELATIONS FOR SATURATED FLOW OF WATER THROUGH CLAY MATERIALS

Abstract

The relation between flow velocity (v) and hydraulic gradient (7) was studied for two porous materials. The volume of the sample was allowed to change during experiment. For the kaolinite, the relation between v and I is non‐linear, the hydraulic conductivity k becomes dependent on time and varies for both increasing and decreasing 7. After some time, k tends to some constant value. For bentonite, k remains constant as 7 increases. However, when I starts to decrease, k decreases accordingly. Hysteresis in the relationship between v and 7 remains unchanged with time. The observed deviations from Darcy's law may be due to deformation of the voids.