Peer-to-Peer Standards Exchange

A friend who is designing an elevated beach house asked me a question about the wind load underneath the house. He could not find provisions in ASCE 7. Should he consider wind load under the house? If no, why not?  If yes, how?

 

Thanks! 

 

 

#WindandWindLoads

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Huajie (Leo) Liu, PhD.,S.E., P.E., M.ASCE
Engineering Manager
LCRA
Austin TX
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Please refer to the new ASCE 7-22, it appears there has been some criteria added for elevated buildings.

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William Rosencutter P.E., M.ASCE
Engr
Meca Enterprises Inc
Broken Arrow OK
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There will of course be wind pressure (both suction and compression) on the first floor level.  The reality is, however, that this is never likely to control the design.  I doubt that designers of these buildings consider it (but don't know).  The live load design for the floor (40 psf), factored by 1.6 will greatly exceed any factored wind load suction pressure.  It would be difficult to get significant wind pressure pusing upward, but it would be a good idea to block the floor joists so that in the unlikely event this happens, the joists don't laterally torsionally buckle.

If the engineer wants to prove all this to himself, he could treat the floor as a "roof" and apply the associated pressure coefficients from ASCE 7

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Ronald Hamburger P.E., F.SEI
Principal
Simpson Gumpertz & Heger
Oakland CA
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Hi Huajie,
Have you considered section 29.4.2.3?  I recognize that a house is typically not a circular tank but perhaps you'd find some useful guidance.  The notion of interpolation based on the clearance is probably something you can adapt/apply.  There's also a 'bread crumb' in the commentary as to where you might find more (Australian reference), possibly even for non-circular objects(?).  I haven't' looked through 22 yet so naturally if there's something more suited there then you'd want to use that instead.  

I agree with Ron that it may have been often excluded and probably won't govern, except possibly with regard to overturning so I'd think it's worth a check.  

Hope this helps,
Keith

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Keith MacBain Ph.D., P.E., M.ASCE
Associate & Chief Analyst
Geiger Engineers, Campus 2
Suffern NY
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