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Re: Lintels and their design

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I would look at either trying to take the torsion 'out' of the beam in
some fashion or use a beam that is more resistant to torsion such at a HSS
(tube) section or creating a boxed section out of the wide flange.

Taking the torsion 'out' could be done by using kickers that brace the
bottom of the beam that prevent the beam from "twisting" by resisting the
torsion by creating a couple (the brace at the bottom and slab [or
something else] at the top of the beam).  It could also be taken 'out' by
detailing the wall such that there is an applied moment at the base
(torque on the beam) that counter acts the torsion due to the
eccentricity.  This is probably more difficult to accomplish but could be
done in theory.

The easiest solution would be to use a closed section.  If an appropriate
size is available, then a HSS (tube) section could be used.  If the span
is too great and there is a depth restriction such that a HSS can't be
used, then you could put side plates on the wide flange to create a box
section that resist the torsion.

HTH,

Scott
Ypsilanti, MI


On Tue, 13 Aug 2002, seaosc seasoc wrote:

> The problem that i am having a headache over is  
> a wide flange beam 20 feet long, simply supported carrying 300 pounds per foot, 4 inches  
> eccentric to center line of beam.
> 
> what guideline can you give me concerning torsion
> thanks
> ----- Original Message -----
> From: Haan, Scott M.
> Sent: Tuesday, August 13, 2002 9:01 PM
> To: 'seaint(--nospam--at)seaint.org'
> Subject: RE: Lintels and their design
> 
> Do you mean to handle torsion from a side loading?  If the framing hung off the side is simply supported most people would ignore the torsion.  There are not code provisions for torsion in the 97 UBC or the 99 ACI 530. If the framing is cantilevered off the side of a lintel, I missed that day in masonry design.   
> 
> If you mean unbalanced loading on different spans - it is required by 97 UBC 1612.1 "...The most critical effect can occur when one or more contributing loads are not acting..." and  by 2000 IBC 1607.10 "... the minimum applied loads shall be the full dead loads on all spans in combination with the reduced floor live load or the full live loads on adjacent spans and on alternate spans."
> 
>  -----Original Message-----
> From: seaosc seasoc [mailto:mjs7737449861(--nospam--at)msn.com]
> Sent: Tuesday, August 13, 2002 3:46 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Lintels and their design
> 
> 
> Dear Sirs
> I would like to know the current philosophy on the design of masonry lintels carrying an unbalanced load...
> 
> Is there a good reference for this problem
> thank you
> 
> -----  
> 
> 
> 
> Get more from the Web. FREE MSN Explorer download : http://explorer.msn.comGet more from the Web.  FREE MSN Explorer download : http://explorer.msn.com
> 


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