Cyclic loading – future use and storage

In the future, an increased cyclical loading of embankment dams is expected due to new operating modes of hydropower plants as a result of the transition to a fossil-free energy system. This project investigates the effects on dams caused by cyclical loading, where the water surface is regulated faster than before.

Water level subsidence is not a new problem, but new modes of operation expose dams to a new load case, for which they are not designed. This project is expected to identify dam types where the new load case may be critical. During the project, different types of dams will be analysed, as the response is expected to be different depending on, for example, structure (zones) and height. The focus of the project is on water saturation, gate pressure, and trigger values to support work on risk management. During the project, laboratory tests are planned on materials from dams, to identify the properties of the materials in the dam. In the case of subsidence, there will be areas of residual gate pressure in the dam body, unsaturated conditions will prevail in certain zones, in order to describe this behaviour, knowledge of the retention capacity of the materials is needed. The focus will also be on cyclic triaxial tests, to obtain more information on how the dam materials react to faster fluctuating water levels. To evaluate future effects on the dam body, numerical modelling will be used. Conditions favourable for particle migration, for internal erosion to occur, can possibly be identified.