How to implement a sheet pile wall into the model?

I am working on a model which should show the difference between the groundwater situation right now and after installing sheet pile walls or a "Spundwand". It doesn't metter how it is called, the important part is how to implement a noflow boundary condition on an edge of an element. It could also be a low flow edge. Or do I have to create elements?

I hope some one can help.

Christian

I suggest two possibilities to represent the internal no-flow boundary condition. Both methods require a representation of the geometry in the FE-mesh.

[list]
[li]Inactive elements[/li]
[li]Low hydraulic conductivity[/li]
[/list]

If you use inactive elements, you assume the sheet pile wall is being completely impervious with respect to both fluid flow and heat transport.

If you are interested in a correct representation of the conductive heat driver within the sheet pile wall, then the better way is work with material properties. Use a very low hydraulic conductivity to introduce impervious conditions with regard to the fluid flow. Furthermore, use a heat conductivity and a heat capacity which corresponds to the thermal properties of the sheet pile wall.

Assure that you use at least two element rows to discretize the sheet pile wall to accurately account for its impervious nature. A smooth gradation between highly refined areas (the wall) and domains with a rather coarse resolution is also recommended.