What is open buildings in ASCE? 1

[tmgczb]

In ASCE, open buildings are defined as buildings with area of openings A₀ in each wall exceeding 80% of gross area of that wall.
Here, I guess a building is open or not depending on if this condition is satisfied for all walls, no matter in which direction the wind blows.
But the definition of A₀ is area of openings in the windward wall(receiving positive external pressure).
So my question is, how should we understand these definitions?
Should we consider wind in different directions separately? That is, under wind in direction X, the building is open but it is not an open building under wind in another direction?

 

[tmgczb]

Waiting for replies.

 

[WARose]

In ASCE 7-16 they've added a statement that if it meets both the definitions of open and partially enclosed, it should be considered open.

 

[tmgczb]

Thank you for your reply. This statement indeed made me less confused.
But for the definition of partially enclosed building,the first condition could only be satified by one of the walls at most. For example, area of openings in windward wall exceeds 1.1 times that of openings in other walls of the building. But if wind blows from another direction, should we still consider the same building as partially enclosed?

 

[WARose]

But for the definition of partially enclosed building,the first condition could only be satified by one of the walls at most. For example, openings in windward wall exceeds 1.1 times of openings in other walls of the building. But if wind blows from another direction, should we still consider the same building as partially enclosed?

Yes. (As far as I know.) You should think of the building as a whole. For example, for open buildings, it (ASCE 7) talks about a "building having each wall at least 80 percent open". In the partially enclosed definition, it talks about the "balance of the building" in comparing the degree of openness.

 

[tmgczb]

I think "windward wall" shall be "one of the walls" in the definition of partially enclosed building.

 

[WARose]

I've e-mailed ASCE on this.....will let you know what they say. (I was second guessing myself on this late yesterday.)

 

[tmgczb]

Thank you for your help. Oh，what is their email address？

 

[WARose]

Oh，what is their email address？

I filled out their contact form and got passed around to several different people. They said that sometimes it takes a while to get a answer from code committees (or their representatives).

 

[tmgczb]

Any reply or not？

 

[WARose]

Any reply or not？

nope. Nothing yet. Will post when I get it.

She did say it sometimes takes them a while to get back. Will ping them (maybe) in a few weeks.

 

[WARose]

Ok they got back to me today. Here is their reply:

[blue](ASCE)[/blue]

Thank you for your inquiry. The following is our response:

“The Enclosure Classification for a building or other structure is determined once and does not vary by wind direction. The amount of openings in the building enclosure can affect the internal pressure differently depending on the location of the openings with respect to the wind and the building plan dimensions.”

Thank you.