New openings in a CMU wall
New openings in a CMU wall
(OP)
I have a client with a 2 story commercial building constructed of CMU walls with wood floor and wood roof trusses. The overall dimensions are roughly 40' by 60'. Currently the windows along the front are very narrow and tall and spaced out nicely. It works great for a night club but they would like to turn it into retail space and open up the windows. I am seismic design category D.
I am comfortable with addressing the vertical loads as well as determining the viability of the lateral resistance (it will either work or it won't).
What I am trying to get my mind around is the reinforcement around the new openings. I don't necessarily like the idea of plates and angles because I'm not sure that bolts are the best way to transfer loads intended to produce ductility. Has anyone used the high strength metal weave that is epoxy applied to the wall? Would both sides be necessary?
Any ideas or advice is welcome.
I am comfortable with addressing the vertical loads as well as determining the viability of the lateral resistance (it will either work or it won't).
What I am trying to get my mind around is the reinforcement around the new openings. I don't necessarily like the idea of plates and angles because I'm not sure that bolts are the best way to transfer loads intended to produce ductility. Has anyone used the high strength metal weave that is epoxy applied to the wall? Would both sides be necessary?
Any ideas or advice is welcome.






RE: New openings in a CMU wall
So essentially the initial removal looks like this.
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We feel that if the block is removed in this fashion, then all the block load from above can be transmitted to the sides and the pinch beam can be removed.
Then we make them put a bond beam at the top the opening of the opening and replace the removed block above once the bond beam is secure.
Clear as mud???
RE: New openings in a CMU wall
Is that the entire length of the opening? That wouldn't work well with a 25' opening, would it? You would need 12.5' of wall above the opening, right?
Why not try needle beam shoring.
As far the end product, why not have a WF lintel above the opening and grout and reinforce the end cells of the wall jambs as required.
RE: New openings in a CMU wall
Yes, it the entire length of the opening. I see your point, but we have never had an architect who wanted an opening that large on a load-bearing wall.
Can you explain this needle beam shoring?
RE: New openings in a CMU wall
RE: New openings in a CMU wall
Mike McCann
MMC Engineering
RE: New openings in a CMU wall
The architect has yet to send me plans, and for now, my mind is set for the worst, it may not be that bad. During the initial site visit I made it abundantly clear that modification of the CMU walls was going to be a challenge. I always tell them that it is like a scratch lottery ticket and I have the quarter. Their proposal will either work or it won't.
The greatest problem I still see is the vertical reinforcement that may not be present at the edge of their proposed opening and what can I put in there to provide the necessary ductility. I appreciate your thoughts on this...
RE: New openings in a CMU wall
RE: New openings in a CMU wall
RE: New openings in a CMU wall
RE: New openings in a CMU wall
You should be careful, I've noticed how well thought out your posts are and I'd have to say that when you speak people listen... If you go off suggesting "bong" beams, then who knows were we'll find ourselves. All in good fun, thanks everyone for your thoughts.