Results shows that, regardless of the density, the internal stability of well-graded till soils is not significantly affected by hydraulic gradients increased stepwise; thus this type of soil are unlikely to be susceptible to suffusion. Gap-graded soils instead can be affected by suffusion when poorly compacted and exposed to hydraulic gradients applied both as a constant load and as a load increased stepwise. Although a clear relation between the rates of increase of hydraulic gradient and its impact on the initiation of suffusion have not been found, it was noticed that the most significant sign of suffusion (variation of hydraulic conductivity) occurs during the first increments of hydraulic gradient.
Results
Results are to compiled in an approach that could be applied in the safety assessment of dams with glacial till core.
