How to model two columns that share a pad foundation in building design

[nkosana.ndlovu]

Hello,

I modelled a building in Revit and exported it to RSA. I have expansion joints where two close columns share a pad foundation in Revit. In RSA these were modelled as separate bases. I get a separate structure error message when I run the analysis. How can I connect the two columns to a common base in the building design module?

Am I to use rigid links? If so, how do I select which node will be the master and which will be the slave?

Or is the correct approach to model the separate sections individually and then manually combine the support reactions outside RSA? This seems a bit tedious, especially when there are many load combinations.

Please advise

[Simau]

Hi @nkosana.ndlovu 

Am I to use rigid links? If so, how do I select which node will be the master and which will be the slave?

Yes, it's a good approch.

Create an extra node between the 2 supports and set it as master node.

[okapawal]

Hi @nkosana.ndlovu 

But if you want to connect supported bottom nodes, you will get calculation error.  It is not allowed to apply supported nodes as secondary in rigid link.

Actually, why do you get separate structure.  I guess there is a beam or slab connecting these columns.  Share a screenshot at least.

[nkosana.ndlovu]

The columns are only connected at the base. How do I model this in Robot Structural Analysis?

[Simau · Accepted solution]

@nkosana.ndlovu 

[nkosana.ndlovu]

Thank you, Let me try this approach.

[nkosana.ndlovu]

Thank you so much. This is the solution!