Stacked W-columns in Portal Frame 1

[DurianNg]

I have a portal frame that is 85ft tall spanning 200ft (the spacing of the frames is 25ft). I have calculated that the column size needs to be W40x297. However, my client has already purchased W24x117s and he is asking if he can “stack” W24 with W16 to achieve the capacity required. I imagine there will be weld full length to get composite action. It is a configuration that I have never come across, has anyone had experience with something like this?

 

[Lomarandil]

Is it possible? Sure is (assuming the resulting composite moment of inertia is similar). You'll even get a beefy longitudinal web stiffener to boot. Can be welded or bolted slip critical.

Is it cost effective? Normally not in North America -- you won't be able to simply weld flange tip to flange tip and mill tolerances mean the flanges may not sit together nicely, so the additional fabrication cost usually costs more than scrapping the W24s and repurchasing the proper columns.

Side note: ធុរេនឆ្ងាញ់