Hefty columns

[formi]

Hello everyone!

I just want to find out your opinion about hefty columns in high-rise buildings or heavy-loaded structures: which type of column section is more economic - box column or jumbo section + cover plates? Any other pros and cons for each type of section?

 

[KootK]

I wish that I were more of an expert in this than I am. Put my advice in the "sketchy at best" category. Several of the highrise projects that I've seen go out of my office over the last few years have gone out with fabricated box columns. These big projects get value engineered every which way so I assume that's the more economic option. I'll ask around as to why.

In the literature that I've read, cruciform sections formed from a Wide flange and two WT's seem to get mentioned a lot. An advantage with that system is that you've got an accessible flange to bolt clip angles to on all four sides for girder connections. It seems to me that a cruciform cross section would have a relatively lousy torsional buckling resistance but that doesn't seem to be holding anybody back.

I can't wait to hear everyone else's answers!

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[SlideRuleEra]

One use of heavily loaded columns that I'm familiar with is the support of an electric generating station's boiler. A utility's boiler hangs from the top of the structural steel to allow thermal expansion to be downward. This is an advantage for operational reasons. Column loads, for their entire length, are extremely high since the high pressure steam vessel has thick steel walls. To my knowledge, without exception, jumbo columns, not box columns, are used.

Since the boiler and its structural steel are usually purchased by competitive bidding, economy is a major factor.

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[paddingtongreen]

I've also used, and seen used, only jumbos in the boiler rooms of power plants. Also, in watching the construction of One Liberty Place in Philadelphia, you should have seen the full pen welds on those things.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin