I want to consider the soil-structure interaction using one of the nonlinear soil material models. Why is it not reasonable to calculate the individual load cases with this model?
In the Steel Design add-on, I have set the boundary conditions in such a way that the I-beam flange is restrained against the horizontal displacement. I then calculated the critical load factors using the Structure Stability add-on, but with no effect on the critical load factor value. What is the reason for this?