Hello all,

i have a question regarding to Sofistik.

Description of the model: a foundation slab is rested on a kopfbalken which supported by piles. the piles are defined as a linear sinkfeder with Stiffness 220000 kN/m per unit area.

nonlinear combinations were defined for the foundation slab deflection.

Sofistik shows logic results with the linear calculation regarding to the Feder deflection but when it comes to the nonlinear calculation, the deflection of the spring is much higher with less spring forces. as shown in the screenshot.

**the question here how would the spring be affected in the nonlinear calculation, is that correct?**

as shown also in the screenshot that with higher reaction force on the Feder (Linear Calc.) we got less deflection compared to the nonlinear Calc. which shows the opposite.