Wind load on irregular building plan

[DTS419]

Buildings aren't always rectangular or square as depicted in the wind load provisions of ASCE 7. For example, in the attached plan sketch, how would you zone this building? Would you consider corner A or corner B to be the end of the wall when the wind is applied to that side of the building?

 

[phamENG]

For MWFRS? B is the corner. C&C? Both of them.

 

[jjl317]

Figure C30.3-2 of the commentary of ACSE 7-16 includes more information on how to address non-rectangular buildings (including information similar to your sketch).

Hope this helps

 

[Eng16080]

In cases like this, where there's a gray area in the code, I typically use the most conservative interpretation, meaning that which results in the greatest loading on the structure. Now, based on your sketch, I would expect the wind loading on this particular geometry to be very close to that of a rectangle. If the indent was greater, then I would expect that to be less the case.

My general approach for wind loading on irregular structures is:
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[li]Use a very conservative wind load. In my case, that might mean 30 psf or 35 psf. If using this load doesn't result in a structure outside the norm, then there's no need to refine the loading further. This might be the case for a building with minimal exterior openings and/or in a geographic location with a lower design wind speed.[/li]
[li]If the more conservative loads are problematic, then use a more refined analysis. I'm guessing that you're using ASCE 7, Chapter 28 (Envelope Procedure) which is a simplified method. Using the Directional Procedure of Chapter 27 is more geared towards irregular structures. There's a publication title "Guide to the Wind Load Provisions of ASCE 7-16" which is really helpful. It includes several examples with irregular shaped structures.[/li]
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