How do I hang a column

[carnahanad]

Hello,

I'm still pretty new at modeling things in RAM so I'm hoping that there is an easy solution to my issue. Does anyone know how to hang a column off of a beam in RAM?

Looking forward to the suggestions!
Alex

 

[Gumpmaster]

Are there any members that frame into the column at the bottom? If not, then I don't think RAM will let you.

You may be able to do it if there are beams at the bottom. I think you'll need to place your column, frame the beams into the column, and then set the releases so that the supporting beams above are fixed on both sides of the column. The beams below would then be simple.

I think this will have the effect your looking for, if RAM will let you do it. You'll need to check your results pretty carefully. I haven't ever done anything like this.

 

[strguy11]

You might be able to make them frame members and set the end fixities but have not tried it. Can you invert the stories? I have done this before with a mezz layer. I actually modeled it on top of the floor, but it was actually installed below. Still need to check the hanger columns separately, but the loads were on the support neam. This might work for you.

 

[rscassar]

Model as a column over and set the stiffness to 0.001 because a tension column will crack. Otherwise just model as a point support and apply the reactions when designing the transfer member.

 

[SteveGregory]

Check this reference from a Bentley forum,

http://communities.bentley.com/prod..._analysis___design/f/5932/p/48562/109971.aspx

 

[rscassar]

Just out of curiosity sir, I understand that hanging columns are frequently used in mezzanine construction, but what is the typical detail for fixing the hanging column to the supporting element above and the detail for the suspended floor which is to be fixed to the hanging column?

 

[carnahanad]

Thanks for the tips everyone! This was for a ramp in the middle of two bays. The ramp goes down to a sky walk that connects to an existing builidng. There would be a top beam which would be level with the floor and then there would be posts hangning off of this beam that would support the ramp as it declines out of the bay. What I have done is actually modeled it flat. I have all the weight accounted for in the model, I'll just have to run some hand calcs for the posts. Basically my model looks like a plan view of the ramp inside the bay. In an elevation view it would looke like there is only 1 floor with no ramp because the posts are not modeled. I thought about trying the dummy column but that sounded like to much work.

I do really appreiate all of the responses. I've gathered some good intel for when I do really need to model something this way.

 

[AllenAdams]

We (Bentley Systems/RAM) are currently in the process of implementing Hanging Columns. That feature will be available in the RAM Structural System in Spring 2011.