Towards migration of fines inside embankment dam cores

Migration of fine soil particles is a slow erosion process in earth and rockfill dams. The phenomenon is more pronounced for old Swedish embankment dams which are exposed to this problem for a long time, around 50 years. Migration of fine soil particles leads to changes in soil grain size distribution, portal, and permeability and these changes can possibly lead to sinkholes and finally dam failure.

This study will be carried out mainly through laboratory experiments, particle-based numerical modelling, and field observations. The existing permeameter will be further developed to visualise migration of fine soil and the soil grain skeleton. The permeability experiments will be performed on dense soils. Models at different scales will be constructed in the laboratories at LTU and at the Älvkarleby Laboratory. The results can help to understand how the mechanical and hydraulic properties of the soil change as a result of internal erosion processes in ageing dams. The results will also contribute to new knowledge for conducting particle-numerical modelling of the mechanical behaviour of embankment dams under realistic conditions. Measures such as grouting will also be taken into account in the modelling.