Studies on the use of hydraulic gradient similitude method for determining permeability of soils

The objective of the present study is to use the hydraulic gradient similitude method for assessing the permeability of soils with varying fines content and unit weights in the laboratory. For this purpose, a custom-designed hydraulic gradient similitude (HGS) test set-up was developed and used. In order to induce varying hydraulic head conditions, the Mariotte tube concept was adopted. This paper also discusses relevant scaling laws pertinent to the determination of permeability using HGS method. The developed HGS test setup was calibrated for varying pressure levels and instrumented using pore water pressure transducers. The model scaling laws implied by the hydraulic gradient similitude method are verified using modelling of models technique with experimental results. Three types of soils, namely, fine sand, fine sand with 10% fines, fine sand with 20% fines were adopted in the present study. The developed HGS test setup enables determination of the permeability of soils of equivalent thicknesses in the field.