Foundation slab after seismic design

[Anonymous]

Hi,
Does Anybody have idea how to LOAD EASY a foundation slab modeled with springs and uplift with reactions from seismic loadcases (modal analysis and CQC combination directional combination)?

I have a building that is loaded with vertical and seismic load and with rigid supports in the columns. Now i want to calculate it with the foundation slab.

I have tried with pseudo static forces created for prefered mode (most current mass % for direction) and direction but sum of rections are not equal?
Any other idea or recomendation ?

[Artur.Kosakowski]

My understanding is that you want to convert values of reactions from the rigid supports that stand for columns to loads. The possible way is to export the table of reactions to Excel and then modify the values multiplying them by -1. After adding the columns with nodal force load definition and list of nodes you can then copy them back to Robot as loads.

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[Anonymous]

Hi Artur, thanks for the fast reply.

Actualy that was not exactly what i was searching. I'm searching for a way to convert dynamic seismic forces in to static, and then to create a foundation sab and calculate the model again.

[Artur.Kosakowski]

Try to convertthe pseudo staticforcesfromeachofthemode into separate static load cases andthendefine ofaquadraticcombinationofsuchcreatedsimpleloadcases.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.