If the selected element is a surface (slab, plate or wall), you’ll see the dialogue below:
Top part
In the top part of this dialogue, you see a graphic representation of the restricted degree(s) of freedom. The orientation of the representation changes with the orientation of the global coordinate system 
.
Middle part
Here you can restrict the various degrees of freedom directly. For each degree of freedom, using the pull-down menu, you can:
- set the degree of freedom fixed.
This can also be done by checking the check box before the degree of freedom. - enter a spring using a value.
Examples on how to calculate a translational spring, can be found here. - enter a function (more info).
- enter the soil layers to be used.
This article explains how to add soil layers to your model.
This article explains how Diamonds handles soil layers in the elastic analysis.
You can define non-linear supports (compression or tension only). For example, in the global Y-direction, this means that an upwards or downwards displacement of the structure is not hindered.
Bottom part
Finally you can define the supports relative to the orientation of the plate.
