I have problems to understand how to model elastic surface foundations. Where do I enter my foundation modulus? And what is the meaning of the other surface elastic foundation parameters?
On the one hand, there are three subgrade moduli in the respective directions related to the local surface axes (Cu,x, Cu,y and Cu,z).
On the other hand, the parameters for considering foundation shear capacity (Cv,xz and Cv,yz) are relevant.
You can assign the nonlinearity to the define elastic surface foundation by defining the failure criterion, for example 'under tension'.
The parameter Cu,z is practically equal to the Winkler foundation coefficient and can be found in a soil expertise.
The parameters Cu,x and Cu,y are friction factors indicating the foundation resistance against horizontal displacement in the respective directions. Thus, you can enter the foundation modulus, for example for the foundation support, in the Cu,z text box as the support is to be acting perpendicularly to the surface.