Large Agricultural Structure
Large Agricultural Structure
(OP)
I would greatly appreciate some opinions as to what would be the best possible options for lateral support for an enclosed agricultural structure. The structure will house chickens. Eave height of 20 feet. 140 mph Florida. Clear span of 70 feet. No interior walls. I have looked at using knee braces to the wood trusses at 4 feet oc like they used to use on these type of structures and anticipate providing the wood truss engineer with the compression and tension loading (approx 4k)at the points of connection of the knee braces. Another option is to use a vertical steel cantilever at some spacing oc. Another option would be to price out a steel building with moment frames. The major problem with the steel is the corrosion factor from the chickens. Any thoughts would be greatly appreciated.






RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
I don't know if it's kosher to point you to the site of another member here but Mr. Slideruleera has some guidance on that topic on his site. Look for the publication that mentions pole barns, see link:
http://www.slideruleera.net/miscellaneous.html
I will be watching to see if that proves to be applicable to your situation since I know of some structures with pinned bases and knee braces and the topic somewhat interests me. Good luck.
RE: Large Agricultural Structure
If you cannot use interior knee braces for the columns, perhaps you could use exterior ones.
Mike McCann
MMC Engineering
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
Propped in the middle it would be economical and strong.
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
RE: Large Agricultural Structure
Looking back I would probably use a double post configuration, at the end of each truss, where either the inner or outer post was canted to serve as a brace for lateral loads. I am skeptical that a single cantilever post will work for 20' eaves and 140mph wind even if completely open. One consideration is that you will have no control over the amount of exterior walls/hording/screens that will be installed once the structure is completed. These things may end up being partially enclosed at some point in the future with no consideration for the additional loads on the transverse frames.