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Re: Allowable Stress

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Yes ASD is the "wrong" code for the problem in question.  You will 
also note that I was discussing "code-based design".

I believe that attempting to make the letter of the code apply to 
every conceivable condition is an unnecessary and fruitless endeavor. 
Unlike some codewriters, I keep in mind that engineering involves 
"the application of scientific and mathematical principles" NOT the 
"application of codes".

I agree that a two-code system is less than perfect.  However, the 
fact that the ASD specification does not address this particular 
problem is not evidence of deficiency.

I agree that mixing codes in the design of various elements of the 
same material in a given structure is a bad idea.  Although this 
approach is used by some designers, it is prohibited by Section 2.1 
of ASCE 7-95.

As to your question:
> How does a common engineer solve that conundrum?
I believe the answer, while not popular, is simple: use LRFD.  For 
years AISC has stated that the Ninth Edition is the LAST edition of 
the ASD manual.  Recently, the specification committee voted with 
respect the the fate of ASD.  The UNANIMOUS decision was that ASD 
will not be revised.

We could engage in long arguments about which code is "better".  
However, I believe that the effort of practicing engineers is better 
spent getting comfortable with the code that is "alive".

-Mike

> From:          "Regis King" <steelfishes(--nospam--at)hotmail.com>
> Subject:       Re: Allowable Stress
> Date:          Fri, 19 Nov 1999 12:58:41 CST

> The "right" code, Mr. Valley?  So then ASD must be the "wrong" code?  This 
> clearly spotlights the dangers of a two code system, where one code is 
> allowed to be used, but is not updated or made more complete as deficiencies 
> and errors are found.  What's the standard of care in a situation like this? 
>   Use one code for some problems, and a different code for others, all 
> within the same structure?  Is it reasonable that code overlaps makes design 
> more difficult to check, and more error prone?  Certainly it wouldn't be 
> ethical to design every member in a building by whichever code produces a 
> more favorable result.  How does a common engineer solve that conundrum?  
> Now I need a legal degree, too?
> 
> 
> >From: "Michael Valley" <mtv(--nospam--at)skilling.com>
> >Reply-To: seaint(--nospam--at)seaint.org
> >To: seaint(--nospam--at)seaint.org
> >Subject: Re: Allowable Stress
> >Date: Fri, 19 Nov 1999 10:33:37 -0700
> >
> >Code-based design of such members is easy if you use the right code.
> >Section F1 of the LRFD Steel Manual indicates applicability to a
> >much wider range of problems and includes specific direction for
> >solid rectangular bars.
> >

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Michael Valley                                   E-mail: mtv(--nospam--at)skilling.com
Skilling Ward Magnusson Barkshire Inc.                  Tel:(206)292-1200
1301 Fifth Ave, #3200,  Seattle  WA 98101-2699          Fax:        -1201