Does ASCE have any language about a building shielding itself or another very near buildin from wind

[engreg]

A Tall (>60') building is built in almost an 'S" shape. I am trying to determine the Cladding Wind load for a large garage door built inside one of the alcoves of the 'S' shape. Does anyone know of any language in the Code about allowable distance from a parellel wall that can reduce or eliminate wind loading. This could also be helpful for shear transfer. I'd think in a city application this is solved by allowing for Exposure B, my building is Exposure C however. Any information on the matter is appreciated. Thank You

 

[phamENG]

No, there is no such language about a building shielding itself. If you want to take advantage of unique building shapes, you either have to a) get a wind tunnel test or b) use your judgement and take ownership of the decision. (Not saying you wouldn't, but stepping outside of the primary guidance to do your own thing has risks.)

It does have language about shielding from another building...and it is that you cannot count on it. After all, if that building was poorly designed and/or constructed, do you really want to tie the fate of your building and its occupants to that?

 

[engreg]

Thank you for the input, another building could also be demolished in the future, so that makes sense.

 

[WARose]

They've always been fairly explicit in ASCE 7 that you can't count on shielding. It makes sense when you think about it: even if something is directly in front of another....that may only eliminate direct pressure vs. other types of pressures that can develop. (Suction and so on.)

 

[phamENG]

You may want to review post disaster damage assessment reports and photos. ASCE has some webinars, and FEMA has reports. You can get a better idea of how wind interacts with real buildings. There are a few that surprised me with how the corner zones "regenerated" pretty quickly in stepped front buildings. While the MWFRS loading is pretty easy to justify "self shielding" in some of those cases, the C&C loading is pretty wild. You can get some local failures in areas you may not normally expect.

 

[slickdeals]

Like others have said, no shielding effects unless you do a wind tunnel test (see Chapter C31 commentary for some good info).
See 27.1.3 and 30.1.4 of ASCE 7-16 pertaining to shielding.