Hi guys
I am a bit confused by N1, Na and Nf when defining the soil in order to design footings. I am working with the following situation: a structure that goes 4 meters below ground level; below 4 meters, a 1.5 m RC column below it is defined in Robot.
![arnauft_0-1620561939538.png arnauft_0-1620561939538.png](https://forums.autodesk.com/t5/image/serverpage/image-id/916878iBC6BA0DBBEC93F3F/image-size/medium?v=v2&px=400)
So, what values should I choose for N1 and Na? Are the ones in the screenshot below correct? Also, what is Nf?
![arnauft_2-1620562375184.png arnauft_2-1620562375184.png](https://forums.autodesk.com/t5/image/serverpage/image-id/916881i8DB2E01169096D7B/image-size/medium?v=v2&px=400)
Thank you