Isolated Footing Against Uplift in SAFE ??? 1

[TekEngr]

I am designing a isolated footing in SAFE but I am confused that how to check the footing against uplift?
Soil pressure are coming as mentioned below
Against dead load Max = -9.08 KN/m^2 and Min = -18 KN/m^2
Against wind load is Max = 53.83 KN/^m2 and Min = -38.74 Kn/m^2
footing is safe against uplift????
Footing is placed at just 200mm below FFL and tuff tile floor on the footing.

 

[hetgen]

Hi shahg123,
I'm assuming that you are using Winkler spring support to model the soil, If so, unless you providing tension anchors you need to change the support condition to compression only and resize the footing.

 

[TekEngr]

Thanks for your suggestions.
I am using the spring point support (PSPR), I am new user of this software you can explain me how we can check the footing in uplift through above values???
Thanks in advance

 

[Agent666]

In earlier versions than 12 there used to be a setting to ignore tension in the soil as a global analysis setting, its been a few years since I used SAFE but it might still be in there somewhere!

The CSI wiki seems to be suggesting you now need to use gap/hook elements to model tension/compression only situations by running a non-linear analysis.

Link

 

[EZBuilding]

You have to run a non-linear analysis that allows for uplift. Any time the program observes tension in the soil it will remove the spring at that location and re-iterate.

This video shows how this can be accomplished:

https://www.youtube.com/watch?v=fzqzjJaeQVg