How to design a 26m long column
How to design a 26m long column
(OP)
Hi there,
I'm designing the wall of a stadium and, due to the design of the roof, I need to implement free standing columns that are 26m tall. The columns can be restrained in one direction (let's say x), but not the other (y), since the space in the 'y' direction must be free. The columns will form the structural support for the cladding formation of an outer wall for the stadium.
Does anybody have any tips for how I could go about designing this, or know of any case studies I can refer to for the implementation of columns at such a length?
Many thanks.
I'm designing the wall of a stadium and, due to the design of the roof, I need to implement free standing columns that are 26m tall. The columns can be restrained in one direction (let's say x), but not the other (y), since the space in the 'y' direction must be free. The columns will form the structural support for the cladding formation of an outer wall for the stadium.
Does anybody have any tips for how I could go about designing this, or know of any case studies I can refer to for the implementation of columns at such a length?
Many thanks.






RE: How to design a 26m long column
RE: How to design a 26m long column
Would I have to design a composite column to be able to develop stability and resistance to buckling?
RE: How to design a 26m long column
RE: How to design a 26m long column
The columns / wall will be mostly hidden, it is the roof that will form the aesthetics of this structure.
RE: How to design a 26m long column
1) KL = 2 x 26 m = 170'. That's far. Real far.
2) Given what you've told us about the loads on the wall it may most closely resemble a column with distributed axial load. That's a bit more favorable of a condition than a tip loaded column. Timoshenko's book on elastic stability deals with this.
3) Given the ratio of wind load to axial load here, your column may really be a beam primarily.
4) If this is a steel column, it may well be a built up section. I'd consider a box section to increase lateral torsional stability. A precast column of some sort might do the trick. In either case, at that height, something trussed resembling a buttress might be ideal if there's space for that.
5) Steel or precast concrete, a splice or two may be required. That should be pretty standard stuff though (splice plates, CJP welds etc). If you have specific questions in this regard, let us know.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: How to design a 26m long column
There will be a lightweight roof supported at the end of the column (well, at the end of various columns surrounding three of the four edges of the structure). This roof, by fault of design, will impose an outward horizontal force to the columns, which I maintain will be counteracted by tying the opposing columns to one another.
1) I'm not sure, given the restraints on the columns, that a k value of 2.0 is appropriate? Even if not, yes, very far.
3) I don't have exact loading from the roof yet, but I gather there will be sufficient loading for the 'column' to be considered a column. However, if not, that may be true.
4) Interesting, I haven't yet encountered a trussed column in design (still a relatively fresh graduate). We are trying to maintain a structure that is as light as possible, so perhaps a trussed steel member would be best.
What do you mean by the trussed column resembling a buttress?
Many thanks for your post, it has given me some good ideas to start with!
RE: How to design a 26m long column
RE: How to design a 26m long column
RE: How to design a 26m long column
Sounds more like K=1.0 now that I understand it better.
See the first pic below. Imagine some more webbing in there. This would be more suitable for the cantilever that I had envisioned. See the second pic below for something closer to your situation. There are really oodles of options for a built of column of course.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.