Effects of hydraulic gradient on the internal erosion by suffusion of glacial till dam cores

The research consists on an experimental investigation of the effects of hydraulic loading on the initiation of internal erosion by suffusion in glacial till dam cores. The main experimental variable is the hydraulic gradient, which is applied both as a constant load and as an incremental load. Other variables included in the study are the soil density and its particle size distribution. The boundary test condition defined by the open size of the filter is also included. The definition of all mentioned parameters intents to simulate potential in-situ conditions in Swedish dams.

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 are to compiled in an approach that could be applied in the safety assessment of dams with glacial till core.




Om projektet


juli 2018 - juli 2020