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Re: DL DEFLECTION

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AISC's educational program last year had a segment on that exact topic.
Contact
Bob Lorenz, Director of Education, AISC  at 312-670-2400.

Overall cambering the girders for the precomposite dead load is the most
efficient (but not exact) way of providing relatively flat floors.  Remember
to take into account some fixity at the girder to column  and beam to girder
connections (this will reduce the simple beam deflection and therefore
reduce your camber) How much fixity depends on what type of connection you
use and the stiff. of the members (design camber can vary from 0.6 to 0.95
of the calculated pre composite dead load deflection) and what you feel
comfortable with.  I recommend not cambering beams if the calculated camber
is less than 1/2" I also recommend specifying cambers in 1/4 in. increments.

-----Original Message-----
From: Eddie Gonzalez <Eagonzal(--nospam--at)ENG.CI.LA.CA.US>
To: seaoc(--nospam--at)seaoc.org <seaoc(--nospam--at)seaoc.org>
Date: Thursday, July 09, 1998 1:15 PM
Subject: DL DEFLECTION


>Please consider the following issue
>
>The October 1992 issue of Steel Tips notes the four available methods to
>control dl deflection while still designing relatively flat floors.  They
are
>1) Varying thickness slab 2) Overdesign Beam/Girder  3) Camber Beam/Girder
4)
>Shore Beams.  With a strong preference toward a combination of methods 1,2
for
>short spans and 1,2, and 3 for long spans, are there any guidelines &
>procedures that may help the designer as he/she seeks to juggle various
>variables such as additional concrete wt., economy, tolerances, and
>constructability.
>
>If anyone would like to share their approach/guidelines or can direct me to
>some insightful articles on this issue, I would appreciate it.  Thank you
in
>advance for you time.
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