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Re: Steel lintel beam

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I would use a shotcrete beam on both sides of the existing wall- about 4
ft. or more deep and about 6" or 8" wide, with about 1.25" dia.
throughbolts and then remove the section after about two weeks of curing.
Are you sure the remaining wall will carry the lateral loads?

Stan Scholl, P.E.
Laguna Beach, CA

On Tue, 22 May 2001 08:42:16 +1000 Gil Brock <gil(--nospam--at)raptsoftware.com>
writes:
> Several points,
> 
> 1       Pre Camber is no use if cracking of the brickwork is the 
> reason for 
> the limit. The brickwork will still undergo the same deflection, 
> only the 
> final beam deflection from the horizontal will be reduced.
> 
> 2       I would not think that lintels of this span were being 
> considered 
> when the .3" limit was created. For a wall without intermediate 
> control 
> joints along its length (at maximum 20' centers and also at the ends 
> of the 
> beam), the deflection should be limited to L/1000. If the joints are 
> 
> provided at these spacings then L/500 should be ok.
> 
> 3       To remove the roof load from the lintel, add another beam at 
> the 
> roof level. You probably have one to provide horizontal support for 
> the top 
> of the wall anyway.
> 
> At 04:02 PM 21/05/01 -0500, you wrote:
> >Mr. Turk: Good points!
> >
> >Ed:
> >
> >Also, I'd suggest providing thru wall control joints at the
> >Lintel bearings to eliminate negative moment issues and account for 
> the end
> >rotation of the lintel.
> >
> >
> >Getting a wall to have a net deflection of 0.3" is going to be next 
> to
> >impossible without cambering the lintel.
> >
> >The amount of camber you're going to need will be relatively large 
> and
> >difficult to control/produce in the shop for a 50'-0" beam.
> >
> >I'd also suggest additional control joints spaced along the span to 
> allow
> >for the sequential loading of the wall
> >And supported roof and give some tolerance for offsetting the 
> camber of the
> >lintel.
> >
> >
> >Good Luck,
> >
> >
> >David L. Fisher, SE, PE
> >Senior Principal
> >Fisher+Horos Structural Engineers
> >372 West Ontario
> >Chicago, IL 60610
> >USA
> >
> >312.573.1701
> >312.720.0505 mobile
> >
> >www.fplushse.com
> >
> >-----Original Message-----
> >From: Roger Turk [mailto:73527.1356(--nospam--at)compuserve.com]
> >Sent: Monday, May 21, 2001 4:48 PM
> >To: seaint(--nospam--at)seaint.org
> >Subject: Steel lintel beam
> >
> >Ed,
> >
> >50 ft *clear span*????
> >
> >Deflection limits:  L/600 per UBC 2106.2.9; L/600 but not more than 
> 0.3" per
> >ACI 530.  I go along with the ACI limits.
> >
> >With only 8 feet of wall above the lintel, you will not be able to 
> take
> >advantage of arching if the span *is* 50 ft, therefore all the wall 
> directly
> >above the lintel should be considered as loading.  My criteria to 
> take
> >advantage of arching is that the wall has to be 1/2 the span "plus 
> a little
> >bit" above the lintel. (The "little bit" is to provide a 
> compression area
> >for
> >the arch.)  Windows and any wall penetrations will also limit when 
> you can
> >take advantage of arching.  (Remember that windows and doors are 
> frequently
> >filled in when remodeling, so don't be too precise on reducing your 
> dead
> >load
> >based on openings.  I neglect all openings when considering wall 
> loads.)
> >
> >Cracking will be the result of deflection, not negative moments.  
> You can
> >frequently see triangular cracks in masonry walls above lintels.
> >
> >Dead load from the roof joists will be dead load to the lintel.  
> Why would
> >you want to consider it live load?  It's there all the time, isn't 
> it?  It
> >isn't moving or movable.
> >
> >HTH
> >
> >A. Roger Turk, P.E.(Structural)
> >Tucson, Arizona
> >
> >Ed Jonson wrote:
> >
> >. > I have a question about using a wide flanged steel beam for 
> supporting
> >an
> >. > opening in a masonry wall.  The opening is 50 feet, with 8 feet 
> of
> >masonry
> >. > wall above.  I'm planning on using a steel beam, designed as 
> simply
> >. > supported.
> >
> >. > I have two questions.
> >
> >. > 1. What deflection limits should I use for the steel beam?  
> Also, should
> >. > the dead load from the roof joists be considered as live load?
> >
> >. > 2.  If I design the steel beam as simply supported, is there a 
> potential
> >. > problem with cracking in the masonry wall due to negative 
> bending
> >. > stresses? I have a low roof that frames in to the side of the 
> masonry
> >. > wall at the same level as the steel beam that will lateral 
> support the
> >. > steel beam.
> >
> >. > Thank you for any guidance.
> >
> >. > Ed Jonson
> >
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> Regards  Gil Brock
> Prestressed Concrete Design Consultants Pty. Ltd.
> 5 Cameron Street Beenleigh Qld 4207 Australia
> Ph +61 7 3807 8022              Fax +61 7 3807 8422
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> 
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