Ke Value for Pole Barn
Ke Value for Pole Barn
(OP)
Hello,
I wanted some opinions on what the Ke value of a pole barn post would be. The post is imbedded in concrete and the free end is connected to steel truss spanning to another wood post.
For me it is something between a true flagpole situation (ke = 2.1) and is the most conservative approach and a Ke value of 1.2 (rotation fixed translation free).
I wanted some opinions on what the Ke value of a pole barn post would be. The post is imbedded in concrete and the free end is connected to steel truss spanning to another wood post.
For me it is something between a true flagpole situation (ke = 2.1) and is the most conservative approach and a Ke value of 1.2 (rotation fixed translation free).
RE: Ke Value for Pole Barn
RE: Ke Value for Pole Barn
With the 2.1 we can only go to about 10.5’ and using 1.65 (right in the middle of 1.2 and 2.1)
Actually I think the 2018 NDS code allows something greater than 50 for construction loading but could not find anything since they changed their book and you can’t download and search the whole thing. I do know the actual equation only needs unbraced length member size and the Ke value so not sure why loading would even matter.
Not disagreeing with you just a discussion point and using Ke values (or other constants) with custom amounts based on experience.
RE: Ke Value for Pole Barn
I guess the best advice would be to take advantage section 3.7.1.2 where it says ..."in accordance with engineering mechanics." and take a stab at calculating the effective length according to the actual members and detail. Time to sharpen the pencil?
When I find myself in similar situations I am tempted to just assume the preferable value (i.e. Ke = 1.6 seems to match what the customer wants, I will just use that since I have a feeling that the Ke would be right around there.
But I think the better approach is to resist that urge and endeavor to make your calculations and your approach more refined. If indeed your feeling is correct you can document it, if you find that you were wrong then you at least you will know where to draw the line.
Also worth noting that IBC, or locally adopted provisions might have specific regulations or exceptions for odd structures like pole barns.