Open Buildings Designed with ASCE 7-10 1

[nategemb]

In ASCE 7-10, should Chapter 27 or Chapter 28 be used to determine wind loads on an open low-rise building? I would prefer to use Chapter 28, but the title for Part 1 of Chapter 28 only indicates that it should be used for enclosed and partially enclosed low-rise buildings, but the user note in 28.2 says that this part should be used for enclosed, partially-enclosed or open low-rise buildings. The user note is not technically part of the code, so I'm inclined to think that chapter 28 cannot be used for open buildings unless there is a good argument that the title to part 1 has a typo and should include open buildings as well.

 

[RFreund]

In the Guide to the Wind Load Provisions of ASCE 7-10 for the example open structure they say:
"Chapter 27, part 1 is used because the example building is an open building. Even though the building height is h<60' and qualifies as a low-rise building by definition, adaptation of chapter 28, part 1, is not appropriate for this example building. Therefore 27.4.1 is used."

I am thinking this means that chapter 27 should be used, especially becasue they have specific diagrams for open structures and consider blockage. What throws me off a little though is they say "is not appropriate for this example building. If they would have said "not appropriate for open buildings" I'd say case closed but either way it seems like they are saying you need to use chapter 27.

EIT

http://www.HowToEngineer.com

 

[wannabeSE]

RFreund,

I wonder why your reference states an open building meets the definition for a low-rise. The definition for a Low-rise does not include open buildings. In the chapter 26, ASCE 7-10 defines "Building, Low-rise: Enclosed or partially enclosed buildings . . ." To me, the user note nategemb mentions may be an oxymoron.

 

[nategemb]

The method used for determining MWFRS loads on an open building in ASCE 7-05 looks like it closely matches the method shown in Chapter 27 of ASCE 7-10, which would coincide with what both of you are suggesting. I think the user note in chapter 28 is incorrect and that chapter 27 ought to be used to determine MWFRS loads on an open building.

Thanks for your help.