A modified permeameter for determination of unsaturated coefficient of permeability

The design details of a modified permeameter used for determining the unsaturated coefficient of permeability of tailings are presented in this Paper. This permeameter can accommodate a large tailings specimen, 200 × 200 × 400 mm high, and uses the Instantaneous Profile Method (IPM) to determine the variation of unsaturated coefficient of permeability with respect to soil suction using a single specimen. The soil-water characteristic curve data can also be simultaneously determined from the modified permeameter. The key design features in comparison to a conventional permeameter include the provision of adjustable sensors that move along with the tailings as it settles due to desaturation during the testing period. The advantages of using a modified permeameter in the determination of the coefficient of permeability of unsaturated tailings are also discussed in this paper. Tests were carried out by providing suction using hanging column technique in the suction range of 0–10 kPa. Such an apparatus can easily be modified to accommodate higher suction values.