Open and free standing structure
Open and free standing structure
(OP)
I am designing a free standing one story commerical shade (flat roof and no walls): 30 PSF snow load, 20 PSF dead love and 90 MPH (exposure B) wind. Since there are no side walls (it is all open on sides), I assume there is no lateral load from wind, except there will be an uplift on roof. I know there will be a lateral force acting on the structure due to dead and live load. Does IBC specify anything in this situation? How much lateral force do I consider in design, the county is looking for a calculations for it.






RE: Open and free standing structure
You need to show something on paper, even if it is next to nothing.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Open and free standing structure
Thanks for the quick response. Do you know if there is a section in IBC that talks about this?
RE: Open and free standing structure
RE: Open and free standing structure
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Open and free standing structure
Aerodynamically, you get some wind drag even though there is no appreciable profile. I don't have a copy of ASCE but this was
discussed before.
You probably won't see this mentioned in IBC because so much has been referenced to ASCE.
RE: Open and free standing structure
If top and bottom surfaces are dead flat it may be prudent to consider a wind drag force of, say 5 psf of plan area.
BA
RE: Open and free standing structure
Long time ago, for an industrial structure open at both ends, my supervisor asked me to design horizontal wind bracing in plan at the roof level for 5 psf on the plan area of the roof. Of course, this load was in addition to the wind acting on the exposed roof truss members. I never questioned him the basis for his assumption but now I think it could be to account for the effect of the wind drag on the roof.
RE: Open and free standing structure
RE: Open and free standing structure
RE: Open and free standing structure
RE: Open and free standing structure
BA
RE: Open and free standing structure
Next time I work on an open structure, I will keep in mind BA retired's comments on wind drag.
RE: Open and free standing structure