Wall pressures for open buildings in ASCE7-05??? 3

[sponcyv]

I am designing an outdoor ampitheatre. All four sides of the ampitheatre are open > 80%. There are two towers on either side of the stage. The roof structure is tied to these towers.

ASCE7-05 doesn't appear to give wind loading for walls of open building structures. Do I neglect any wind load on the walls of the towers? I've considered applying the facia load to the towers, but this seems pretty conservative.

I have attached a pdf for reference.

 

[rscassar]

Definatley need to consider wind loading on the towers, I would distribute force as per an enclosed building.

 

[msquared48]

I agree - be conservative here.

Mike McCann
MMC Engineering

 

[JedClampett]

I would go one step further and use partially enclosed pressures on the walls. Note that this only changes C and C pressures.
For something this unusual and hard to analyze, you might want to consider a wind tunnel analysis. I've never requested one and I don't know what they cost, but there's got to be a price point where the material saving is worth the cost.

 

[Ron]

sponcyv...I would start the analysis with the towers. The roof is a supplementary canopy designed as an open structure. Analysis of the towers will depend on whether it meets the definition for an enclosed or partially enclosed structure.

I see quite a few structures that were analyzed as "enclosed" when they should have been analyzed as "partially enclosed".

Also check the provision in ASCE 7 for "Other Structures", particularly flexible structures.

 

[sponcyv]

Jed,

The towers themselves do not meet the requirements to be considered partially enclosed. Also, the budget and timeline on the design will not permit a wind tunnel analysis.

Ron,

I will look in to the "other structures" and compare with the enclosed wind forces.

Thanks