Abstract:
Provided that inter-particle flow remains laminar, hydraulic conductivity tests can be carried out
in a centrifuge to accelerate flow, allowing the hydraulic conductivity of relatively impervious
materials to be measured within a reasonable time. It is well documented that the inter-particle
flow velocity in the centrifuge increases linearly with acceleration, and a debate in the literature
deals with whether hydraulic conductivity also scales with acceleration or not. A number
of hydraulic conductivity tests were carried out using seepage columns in the geotechnical
centrifuge in which pore pressures were recorded within the samples during testing. When
hydraulic conductivity is calculated from the hydrostatic potentials measured during testing,
the hydraulic conductivity is found to be independent of the imposed acceleration. It is
therefore advocated that the hydrostatic potential is scaled in the centrifuge rather than the
hydraulic conductivity. It must therefore be recognised that the hydraulic gradient used in the
conductivity calculation does not remain constant, but changes with the imposed acceleration.
