ON THE CHARACTERIZATION OF PROPERTIES OF AN UNRIPE MARINE CLAY SOIL .2. A METHOD ON THE DETERMINATION OF HYDRAULIC-PROPERTIES

A method is proposed to determine both the moisture retention characteristic (MRC) and the unsaturated hydraulic conductivity-pressure head relation for an unripe marine clay soil. This method relies on the evaporation method but uses the shrinkage behavior of the soil to include the effect of changes in the moisture content on the soil matrix. Measurement results for the MRC of the soil at two different ripening stages are compared with the results obtained from the standard measurement technique and evaporation method. The hydraulic conductivity-pressure head data from the new method are compared with measurements obtained from the evaporation method and the one-step outflow method. The three methods for determining the MRC result in different curves when the moisture content is calculated on the original soil volume. Differences are the largest near saturation (PF 0-1.5). On the basis of actual soil volume, however, the differences are much smaller between the proposed and the standard method. The one-step outflow method results in lower hydraulic conductivity compared with the other two methods. Almost no difference is found between the proposed method and the evaporation method.