ABSTRACT
In dynamic centrifuge modelling, to resolve conflicts in scaling of time between dynamic and diffusion events, viscous fluids are used to reduce a model’s permeability. In this study, permeability of Toyoura sand is measured with constant head permeability tests by varying the fluid viscosity, paying attention to transient changes in its permeability. Types of fluids used in the tests are purified water and methylcellulose (MC) solution. Results show that the permeability of sand with MC solution continuously decreased with the fluid passing, whereas it remained constant for purified water. It is found that the reduction rate of the permeability has two phases indicating possible clogging of MC fibres. By modelling of models of liquefaction model, the effect of permeability reduction is confirmed to be relatively minor. However, care should be taken if the duration of the diffusion process or settlements after liquefaction is of particular interest in testing a model with MC solutions.
