RAM SS Shearwall On Top of Steel Beam

[tj89]

Hey guys, new here! Been a long time lurker and finally diving in and getting involved... My question relates to modeling a wood building on a steel podium in RAM SS. Essentially I'm trying to get the overturning forces from the walls above into the supporting beams below, these beams aren't necessarily my LFRS but just transfer beams. The issue I'm having is if I have a 3 story, 30ft tall wall with 1 kip at each level, the over turning force at the base is 60k-ft... Will the supporting beam below see the 60k-ft? If I resolve the shear wall into it's T&C components of 3.33kips at each end and apply those as point loads the difference in forces is almost 10x lower than the overturning of the wall, about 3 kip-ft in the beam below. If I make the wall 1/12" thick and reduce the E way down I get about 30k-ft in the beam from the wall above.

I'm not convinced that either are 100% true, I feel the T&C components is false due to this wall isn't infinitely stiff spanning between it's end conditions, however I don't believe the 30kip-ft is realistic either.

Has anyone else performed this design in RAM SS before? If so, how did you go about laying out the structure?

Thanks!

 

[SethGuthrie]

It's kind of tricky to models walls on top of beams. If the walls are modeled as lateral members then they stiffen the beam. If they are modeled as gravity walls then you can't easily apply the lateral forces. For some tips check out these posts on Bentley Communities:

https://communities.bentley.com/pro...alysis_and_design__wiki/ram-ss-walls-faq.aspx

https://communities.bentley.com/pro..._and_design__wiki/10202.modeling-podium-slabs