STAAD Foundation Uplift Pressure

Hi,

In my SFA, please refer to "Preliminary Design - Isolated" job. I have set that the minimum contact area for both service and ultimate load cases should be 100%. However, for Isolated Footing 1, I noticed that there is still negative pressures underneath the footing (see photo). Why is it that there are negative pressures but the table (see photo) shows that there is no loss of contact?

1641.[CE 196] - Isolated.sfa

  • I see that you are using Net Bearing Capacity inputs. When you are using the net bearing capacity option, you are ignoring the contribution of footing selfweight. I would suggest you to change the Bearing Capacity input to "Gross Bearing Capacity Input" and enter the gross bearing capacity values in the job, you should get positive corner pressures. 

    Answer Verified By: Louis Flores