Wind Corner Zones on Walls Theory
Wind Corner Zones on Walls Theory
(OP)
ASCE is clear that the corner zone width 'a' is "10 percent of the least horizontal dimension or 0.4h, whichever is smaller, but not less than either 4% of least horizontal dimension or 3 ft." Working for a curtainwall company, I have to use this rule on a regular basis. But, I was asked WHY the least building width influences ALL of the corner zone dimensions, and I can't come up with a legitimate reason other than "the code says so." Does anyone know how ASCE arrived at this rule or have an intelligent theory on it? Thanks for the help.






RE: Wind Corner Zones on Walls Theory
Read the commentary for Chapter 30 to get a feel for where all these came from. That's my guess anyway.
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RE: Wind Corner Zones on Walls Theory
Mike McCann, PE, SE (WA)
RE: Wind Corner Zones on Walls Theory
The wind load depends on the total height of the building
SO if you a high building the wind load is higher also for the lower bottom parts of the building
for example...designing the entrance facade at ground floor
two buildings... different wind load for the entrance facade because one of the buildings is much higher than the other one
somehow not logical.... or ?
best regards
Klaus
RE: Wind Corner Zones on Walls Theory
RE: Wind Corner Zones on Walls Theory
Here is an example to better illustrate my confusion: Let's say you have a 100'x30' building and a 100'x90' building. Assuming the 'h' is large enough and the same for both buildings, the corner zones will be 3' and 9' respectively, correct? It is hard to imagine WHY there would be a different corner zone width for the 100' faces of the two buildings when they are the exact same face. In my line of work, the corner zone may require additional reinforcing, fasteners, weld, etc. so this dimension is pretty important.
RE: Wind Corner Zones on Walls Theory
These typically would be modeled building shapes of various sizes and configurations and from those tests I speculated that the size of the building may have revealed a relationship between the higher peak corner pressures, their extent away from the corner, and the dimensions of the modeled building.
The fact that you can't "picture" this between a 30 ft. wide and 90 ft. wide building is reasonable - but my "guess" is that wind pressure behavior at corners is quite complex and not as intuitive as may be supposed.
You might try contacting Texas Tech university, or perhaps Dr. Kishor Mehta or his firm (here: http://www.depts.ttu.edu/ceweb/faculty/faculty.php...) as they/he does a lot of wind research.
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RE: Wind Corner Zones on Walls Theory
Klaus...the leeward side of the building experiences the affects of wind blockage mentioned above...this affect(suction), I would assume is approximated by using the full height of the building...if for example, the first floor was totally open, then,IMO, one may be able to use the varying press according to hz for the leeward side....
RE: Wind Corner Zones on Walls Theory