Wind load on canopies

[mlzahn]

Does anyone know of any literature that addresses wind load on canopies? I have been designing canopies for eave loading, but I honestly don't think eave loading is appropriate. Eave loading involves continuous air flow on top with little airflow below. This would certainly require significant overall upward pressure due to Bernoulli's principle. But I don't see that affect happening at canopies. In fact, for low canopies on tall buildings, I don't see why airflow would be any different between above and below the canopy.

 

[JedClampett]

I would consider any loading that would prevent me from underdesigning the canopy. You have all kinds of shielding, wind tunnel effects and strange gusting. And if you mess up, the canopy will take off and land in the middle of the freeway.
Be conservative, be very conservative.
For a recent lesson, see the link about the Cowboy's practice facility, below.

 

[MikeHalloran]

Google >broward county airport canopy< for a limit case.

The canopies were beautiful and effective when new.
Hurricane Wilma stripped off all the fabric but left the sturdy cables.
Repairs still not quite complete.





Mike Halloran
Pembroke Pines, FL, USA

 

[Ron]

mlzahn...I've designed hundreds of canopies in high wind areas. I've typically treated them as open structures under ASCE 7 (assuming you are in the US). In some instances, they have to be designed as overhangs, if they are hanging from a building wall. If they are free-standing, they are open structures. Coefficients are based on monoslope roofs (Cf).

 

[jonathanpye]

British codes give clear guidance on canopy wind loads
Check out CP3 and BS6399
Both give clear guidance, and allow you to calculate wind loads depending on whether the canopy is fully open below, is blocked below, or partially open

Failing that, and for simple small canopies only, I have sometimes calculated the wind pressure as if it were a roof, and then factored by 2.

UK based Chartered Civil and Structural Engineer

 

[mlzahn]

Thank you to all who resonded.