gas station canopy
gas station canopy
(OP)
An architect is wanting me to design a drive thru that has only 2 posts, similar to the structures they install over gas pumps. Has anyone ever designed one of these? Are the columns designed as a cantilevered column to resist lateral loads? It seem this is a very unstable structure. I've noticed that alot of the new canopies have 4 columns and the ones that have 2 columns have alot bigger columns than the older ones.






RE: gas station canopy
The columns are designed as cantilevers to resist lateral loads as well as unbalanced snow load on the roof. The foundation must be able to resist these eccentricities. Roof beams must be connected to the top of each column with a moment connection adequate to resist unbalanced wind uplift and snow load.
Structures like this are fun to design. Do not skimp on the column size and enjoy the experience!
Best regards,
BA
RE: gas station canopy
It has been my experience (thus far), wind uplift and overturning always controls the size of the foundation.
RE: gas station canopy
If you "heard" it on the internet, it's guilty until proven innocent. - DCS
http://www.eng-tips.com/supportus.cfm
RE: gas station canopy
RE: gas station canopy
I bet that wasn't factored into the original design.
rmw
RE: gas station canopy
RE: gas station canopy
RE: gas station canopy
These things (along with pre-engineered buildings) are the first structures you see on the Weather Channel floating away during a windstorm. It says to me that we don't use the same factors of safety for these as we do for other structures. I don't know that ASCE 7 properly covers them.
RE: gas station canopy
Otherwise, design as a cantilever and ensure that the foundation has capcity to resist overturning. You may be able to use outriggers to tie the columns together in the out-of-plane direction.
RE: gas station canopy
The use of these words varies somewhat with geographic location, but an awning is usually attached to a larger structure. In the OP, I think canopy is appropriate.
RE: gas station canopy
RE: gas station canopy
RE: gas station canopy
Thanks in advance.
RE: gas station canopy
RE: gas station canopy
Is that true? Are they designed to do that? I almost couldn't believe it. If it was moving that much in a 30 or 40 mph wind, what would it do in the 90 mph wind that it was designed for?
RE: gas station canopy
RE: gas station canopy
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RE: gas station canopy
That's classic.
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RE: gas station canopy
If it is feet, then my only advice would be RUN!!!!!
RE: gas station canopy
RE: gas station canopy
I checked one of these one time where it was not really stable - sort of a teeter-totter in one direction. The designer inadvertantly was relying on load-symmetry to "balance" things out. Otherwise they might have seen the deflections you are describing.
RE: gas station canopy