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RE: Plan Check (was Re: Rigid Wood Diaphragm?)

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Dennis,

A lot of what you point out is very true.  I would just say that software
programmers don't necessarily understand the intent or wording of the code
better because the look any more closer or have more insight.  Instead, it
is to some degree a function of lots of people looking over their
shoulder.  Even though they absolve themselves of responsibility and
liability, they do have a vested interest in making sure it is right (who
would buy a program that does things the wrong way...but then we all buy
Microsoft stuff, so go figure).  Thus, they do things like alpha and beta
testing.  They will also misinterpret the code on occasion and have it
pointed out to them, at which point they will create a "bug" fix.  I will
certainly admit that they likely spend a lot more time making sure that
they have a solid rationale for their interpretation.  But, then they
usually don't quite have the same pressure in terms of deadlines that
engineering working on construction projects do (their deadlines are more
self-imposed...take RISA...they considered it much more important to get
it right than hit a date, thus they only just released RISA-3D with
concrete support recently even though they intended to get it out earlier
this summer).

Regardless, use of _ANY_ computer program software requires care.  Whether
or not the computer programmer understands the code or not does not really
matter...the individual engineer sealing the drawings is the one required
to understand the code and takes on the potential liability and
responsibility in that regard.  Thus, those that assume that the
programmer got the code interpretation stuff right makes a you know what
of themself.  Thus, a software company can test their product till hell
freezes over, but the plain simple fact is that THEY don't lose their
license if something is wrong...I do.  So, even though they might
potentially have better access to information and may even have a better
chance at interpreting the code that one individual engineer, it is still
that one individual engineer that must be confortable with the results
that get put on paper since it is that individuals tushie on the line.

Regards,

Scott
Ypsilanti, MI


On Fri, 17 Oct 2003, Dennis Wish wrote:

> Scott,
> This is true and I have made errors (only one that I know of) in the
> first spreadsheet that I wrote for seismic retrofit of unreinforced
> masonry. This was also an error in the interpretation of the code.
> With that said, the point I was trying to make relates well to Multi-Lat
> - the freeware spreadsheet on the Structuralist.Net website. Multi-Lat
> required probably close to a thousand hours writing and releasing with
> known limitations. However, to accomplish this I was able to draw upon
> the knowledge of those I knew who were closest to the SEAOC Seismology
> Committee as well as the sample problems in the ICBO Seismic Design
> Manual Volume II. I was even on the review committee for the cold-form
> problem in the manual and as such had documentation (drafts) that were
> given to reviewers that also allowed me to question and debate changes
> from previous codes. I didn't simply accept that Doug Thompson or Bill
> Nelson's problems that were published in the Wood Frame (Light-frame)
> section of this design manual were correct - if I couldn't trace the
> numbers I was compelled to contact them and ask. Furthermore, the use of
> spreadsheets like this made it easier for others to questions those
> issues in the code that SEAOC has backed down from and would make it
> easier for future code writers.
> The point here is that when I walked away from the finished product, I
> felt that I had a much more in-depth understanding of the code. Whether
> or not I agree with it won't be resolved anytime soon. However, those
> that use the spreadsheet probably won't have as deep an understanding of
> the code or the spreadsheets working as those who are willing to open
> the program up and study it - questioning those issues they don't
> understand.
>
> We need to do this with the code and I don't think many of us do. Most
> assume intent of the code writer and leave it at that. If they debate
> the issue with the plan reviewer then it is a question of who is more
> convincing. To this day SEA has never published an Erratum on the code
> that tracks back to the original ideas that led to the publication of
> the code section for light-framing. We have a good idea, especially with
> the help of ACI, PCA, AISC, MIA and other material groups how to design
> using the materials and historically the methodology to resist lateral
> loading for seismic and wind has been pretty good. Yet the same is not
> true of light-framing and there is no record of the step taken to arrive
> at the current code.
>
> Look, my opinion of the code for wood structures is well known. My point
> is that those who write computer programs may have errors - but most of
> the errors are probably logic errors and not interpretation of the code
> unless the code is "unfinished" with it is published. The example I used
> was the use of RGA 1-91 for the retrofit of unreinforced masonry back in
> the 80's as we were learning and SEAOSC was "tweaking" out the code
> based on the originally published ABK Method done around 1980 (give or
> take a few years). I'm sure Nels Roselund has more specific information
> on ABK as he worked for the "K" - John Kariotis back then.
>
> I think this was an exception to the rule, but the results have held up
> to this date that the methods are valid but detailing has changed and
> probably will continue to evolve.
>
> Dennis
>
> -----Original Message-----
> From: Scott Maxwell [mailto:smaxwell(--nospam--at)engin.umich.edu]
> Sent: Thursday, October 16, 2003 10:41 PM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Plan Check (was Re: Rigid Wood Diaphragm?)
>
> Dennis,
>
> Ah, be careful my friend.  Those that program/make structural software a
> just as prone to misinterpreting the intent and wording of the codes.
> That is why they include a nice little disclaimer that (attempts to)
> absolve of all liability/responsbility.  Thus, I am _ALWAYS_ careful
> when
> using structural software, especially design software that makes use of
> code provisions.
>
> Regards,
>
> Scott
> Ypsilanti, MI
>
>
> On Thu, 16 Oct 2003, Dennis Wish wrote:
>
> >
> > Outside of writing computer software (the ultimate in an engineers
> > evolution to understanding fully what the code writer intended and to
> > find mistakes in the logic of the intention at the same time) the plan
> > checker offers the great majority of us who are in SOHO or small
> offices
> > that don't have the time or the employees to provide peer review an
> > opportunity to find even one mistake or misinterpretation of the code
> > that we might have that can save a life.
> >
>
>
>
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