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Re: Wide Shallow Beams

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I am going to disagree here.

The codes tend to lag behind what is done in the field due to two primary
factors in my opinion: 1) you cannot just put a provision in the code for
the hell of it...you need to have some sort of justification or research
to "prove" its effective use.  Most provisions in the code are a result of
first verifying how the behavior of the "thing" is in research.  This
research takes time to do and then disseminate the information.  I am sure
that there are a lot of things that have "worked fine in practice" but
were latter determined to not be so great after some closer looks were
taken.  And you can even have situations where a subject is throughly
researched and still later find out that itis not all the great (take for
example what we have recently learned on the "traditional" steel moment
connections).  2) It takes time to process something through the code
process.  The code process does not tend to move to rapidly.  This is
partly because of the fact that most material and load codes (ACI 318,
ASCE 7, MSJC, etc) are done in a consensus process.  This basically means
that a provision must go through several steps and must essentially (not
quite true, but I will leave it fuzzy for the moment so that I don't bore
you with a dissertation) be agreed upon by everyone.

I also disagree that "...they just keep doing what they were doing."  A
lot of code language is confusing first an foremost because some of the
topics are not that straight forward, yet codes are "supposed" to be
"cookie cutter" stuff.  ACI 318 gets this knock because reinforced
concrete is a much more difficult "thing" to get one's hand around (sorry
Charlie).  Since steel is a much more homogenous material, it is easier to
create more simplified "stuff".  R/C has more "variables" to deal with so
the "descriptions"/"methods" get slightly more complex.  This is not to
say the steel code guys have it too much easier...they just have different
issues to deal with.

Additionally, keep in mind that the people writting these code provisions
are human.  They make "mistakes".  I would suggest that you try writting
some code provisions in mandatory language and see how unambiguous you can
make them.  It ain't so easy.  Keep in mind that a code provisions must be
written in mandatory language...this means that you cannot "suggest",
"recommend", etc how to do it...the provisions must explictly say do it
this way...no "ands", "ifs", or "buts".

And while it is primarily the committee's responsibility to write the
clear, concise code provisions, there is some responsibility that falls on
the shoulders of the code using engineers.  Even consensus based code
(i.e. ACI 318, MSJC, ASCE 7, etc) must have a public comment period.  This
is a time for the public (i.e. working stiff engineers) to comment on the
proposed code revisions.  This is the time for you to point out things
that don't make sense in the proposed changes or things that you just
don't agree with.  The committee then must take those comments under
consideration.  How many on this list have supplied some sort of comment
on a proposed code revision?  I know for example, that even though I
posted the fact that the MSJC (masonry code) was open for public comment
on this list, ACI/TMS/ASCE still only recieved about 3 or 4 total comments
on the proposed changes.  Factor in that this was also announced in ASCE
puclications, ACI publications, and TMS publications and I consider that
rather pathetic.  I suggest that practicing engineers avail themself of
the system.  I admit that there are some within the various organizations
that like the fewer responses and as a result don't advertise the public
comment as widely as they could.  This is because more comments make more
work and can bog the system down (i.e. potentially make it take longer to
change code provisions).  I personally think this is a mistake...I think
that everyone should be aware of the public comment periods and strongly
encouraged to participate.  That was one reason why I pushed to get
announcements of ACI public comment periods in magazines like CE News and
Structural Engineer while I was working for ACI.  To a certain degree
though, it becomes a moot point...regardless of how much it is annouced,
there a many who just "don't have the time to send in a comment".

And I can even say that the committee's would be more than glad to hear
about areas that you find confusing or unclear.  I know that ACI is
working on trying to make the 318 more "user friendly".  But that becomes
a rather difficult process if they don't have feedback.  So, I would
suggest offering any constructive comments to ACI, TMS, AISC, or ASCE.  I
would be careful about comments that can be percieved as
"attacking"...after all, how would you respond if someone commented that
your structural drawings that you produce don't make any sense but you
just keep doing what you are doing?  I know that I would not like it too
much.

Regarding the individuals on the committees...I will agree that many who
do get involved in writing code provisions do come from an academic
background, which can mean that they may not (or may) have too much
"practical" experience.  However, keep in mind that in order to write the
code provisions (i.e. the "cookie cutter" stuff), one needs to have a very
good understanding of the theory and details of what is happening.  If
every one understood all things structural, then the need for codes would
be greatly diminished.

I also know for example (since I know personally know the incoming chair)
that there is an honest attempt on the ACI 318 committee to get a well
balanced committee.  That is, they attempt to get practicing engineers,
researchers/educators, contractors, and even building code officials.
Sometimes this is not an easy process to accomplish.

I guess I will just close with the suggestion that if you don't like
something in the codes, then get involved.  And than does not just mean
"get on the committee".  Since it can be rather difficult to get on some
of these commmittees (depends on each organization...it is actually very
easy to get on an ASCE code committee, but that creates some problems that
they then have to deal with), getting involved can mean just reviewing the
public comment period information and sending in some comments or just
forwarding some constructive comments to one of the organizations.

OK, I will get off the soap box now...

HTH,

Scott
Ypsilanti, MI


On Mon, 18 Mar 2002 GSKWY(--nospam--at)aol.com wrote:

>
> There is no code reference for sizing wide shallow beams for either
> post-tensioned or conventially reinforced construction.  In general, the
> codes tend to lag far behind the industry when it comes to post-tensioning.
> Much of what is considered common practice is not covered in the codes.  What
> does get into the codes is often written in such a way that noone understands
> it anyways so they just keep on doing what they were doing.
>
> The codes,  ACI 318 in particular,  are often written by people who, although
> they may have a great deal of education and even experience in a given area,
> are typically not in a position where they ever have to apply what they have
> written.
>


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