shelf angle lintel

huangyhg

shelf angle lintel
i have a situation where there is a lintel that forms a vertical peak, but also protrudes horizontally at about a 15 degree angle.  it's about a 8 foot opening with about 3 feet of brick above.  below is my attempt at a picture of it.
   
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would a single angle lintel work okay for this situation?  do i need to worry about torsional effects?  i'd like to keep it a shelf lintel because it is a wood framed building and there isn't a good place to put any steel columns or beams in this location.
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i would lag screw it back to the wood framing.  i foresee a lot of torsion on that lintel.
daveatkins
with the horizontal projection producing torsion, i would want it tied back to a diaphragm at the peak and to the wall framing at each bearing.
another possibility would be to put a horizontal tube in the wall at the elevation of the peak and frame that into tube columns at each side of the window. the angles could then span from the tube column up tot he horizontal tube at the peak.
i would definately look at putting some tube columns in the stud wall either side and cantilevering it from them. you could use a channel inside the brick with the angle lintel welded to it.
this lintel will not work unless it has been specifically designed as there as no capacity for arching action.
csd
csd72 - what do you mean by:
"this lintel will not work unless it has been specifically designed as there as no capacity for arching action."
are you concerned about the peak in it?  i have designed it to not include arching action.  
i would put steel columns in it if i could, but this lintel is about 35' off the ground so the columns would have to be that long...not very economical.  would lag bolting it back to a wood beam work just as well?
i think with the horizontal projection, the typical loose lintel concept will not work properly, or at least not be very easy to analyze and assure yourself that it will function properly...
that's why i think the comments above are good - that you should look at ways of suspending the brick off the structure as opposed to attempting to span with a stand-alone flexural element.
structuralnerd,
yes i agree my comment was a bit vague. i will explain.
at a typical straight opening, the brick has the ability to arch over, so even if you improperly size the lintel the brick over will most likely crack but otherwise bea alright. in other words there are alternate load paths.
in this case there are no alternate load paths so unless each and every part of your support system works correctly you run the risk of a local collapse of the brickwork. for this reason i suggest you look at it in detail.
the steel 'columns' mentioned are really more like mullions and would only need to go to the nearest floor above and below. you could take the vertical load out by bearing on the masonry either side of the opening.
csd