Modelling of physical phenomena at water-soil interface

In the construction of structures that are built into the sea bed knowledge about the stability of the surrounding soil is crucial. For being able to place foundations in the seabed, excavations are necessary, which involve under water slopes. This was the motivation for the on-going research project, in which the focus lies on the stability of slopes under the influence of waves, the tide or ground construction work. However, once the structures are established, new challenges arise, two of which will be handled in the new research proposal: due to the skeleton-like shape of the soil, a fluid flow can establish inside it. This can lead to internal erosion (suffusion), which causes stability issues. An important application in this context is the flow around a sheet pile which will be studied closely. The second matter concerns the stability of dams: in many cases a dam separates two areas with different water levels. Between the region of high and low see level, seepage flow can be observed, and the developing phreatic line is of great interest. In the proposed project this topic will be investigated through the example of a vertical dam. The main issue will be the depiction of the air-water surface within the soil, which will require an advanced modelling of the surface tension. A combination of experiments and numerical simulations will be used to first develop suitable models and then deduce general statements about the effect of fluid or fluid-air flow within soil structures and around non-porous objects, i.e. sheet piles. As the soil structure is, in comparison to the overall problem size, quite fine, a multi scale approach will be used. Thus, for the numerical modelling of the above described processes coupled CFD-DEM simulations are used.

No additional funding sources recorded.