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RE: Upgrade Fatigue?

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I feel your pain with transitioning to the new wind provisions.  I did a 
project in a jurisdiction in west Texas that has already adopted IBC 2012 / 
 ASCE 7-10.  The questions I got were from the curtain wall designer, who 
was having a hard time figuring out how he was going to make his system 
work with 120 mph wind (I know -- no big deal in Florida).  He had done all 
 kinds of projects in that area with 90 mph wind, and was sure that my 
documents were wrong.  I had a hard time trying to explain to him that the 
new 120 mph wind was the same as the old 90 mph wind.  In fact, because of 
the reshuffling of load factors, gust factors, importance factors, etc., 
the new 120 mph might actually result in a LOWER design pressure by a few 
percent.  I wanted to tell him, "Just do what you would normally do, and 
it'll all be fine."  But, of course, they need to follow the provisions of 
the current code, as well.  I don't know if their engineer took the plunge 
and got up to speed with ASCE 7-10, or if he just decided to leave that 
effort for another day.

-- Joel Adair
    SHW Group
    Plano, TX

-----Original Message-----
From: seaint-seaosc(--nospam--at)mail-list.com [mailto:seaint-seaosc(--nospam--at)mail-list.com] On 
Behalf Of Carl W. Jenne, P.E. Sent: Wednesday, April 10, 2013 4:03 PM
To: seaint-seaosc(--nospam--at)mail-list.com
Subject: RE: [SEAINT-SEAOSC] Upgrade Fatigue?

In Florida we've already adopted ASCE 7-10.  The revised wind provisions 
with its different wind speeds have been a real hassle to explain to 
architects.

Architect:  "What's the wind speed in that location?"  Us:  "It depends.
The wind blows harder on a hospital than it does on an office building."

In order to save us the trouble of multiplying by 1.15 they increased the 
physical size of the code and opened a can of worms.  Ever try to explain 
mean recurrence intervals to an architect?

Having said that, it's not within our power to refuse to go along.  All we 
can do is kvetch.

Though Florida doesn't have seismic problems (by legislative fiat) we also 
design in other locations.  Here's a dramatically oversimplified 
illustration of a AISC 341 catch-22:

In an ordinary concentric braced frame, you’re (theoretically) allowed to 
 use K-braces.  In order to make sure you don’t have buckling in the

Truncated 3415 characters in the previous message to save energy.

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