New opening in cmu wall
New opening in cmu wall
(OP)
Hello all,
If they are planning to make an opening in a cmu wall what is the retrofit design approach for this? Can anyone give me an idea on how I should approach this design? I am quite lost.
JO
If they are planning to make an opening in a cmu wall what is the retrofit design approach for this? Can anyone give me an idea on how I should approach this design? I am quite lost.
JO






RE: New opening in cmu wall
How tall is the wall?
Need a little more information here.
Just finished a retrofit today.
Mike McCann, PE, SE (WA)
RE: New opening in cmu wall
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
Mike McCann, PE, SE (WA)
RE: New opening in cmu wall
The channel above the opening is to take care of the gravity loads correct, essentially a lintel? is that all i need? how about to analyze this wall as a shear wall?
Thank You
JO
RE: New opening in cmu wall
RE: New opening in cmu wall
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
Mike McCann, PE, SE (WA)
RE: New opening in cmu wall
JO
RE: New opening in cmu wall
Basically you need to make sure the wall works for all the loads it will see.... Dead, live, snow, wind and seismic.... If something doesn't work you need to reinforce it so it does.
RE: New opening in cmu wall
JO
RE: New opening in cmu wall
What are you fastening the channels with?
Thanks
RE: New opening in cmu wall
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
Where are you getting design values for thru bolts?
Pre-deflected channels - yea, that's gonna happen.
RE: New opening in cmu wall
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
Also check gravity and out of plane? This will be taken by the steel frame?
Also, what are wind columns mentioned above?
JO
RE: New opening in cmu wall
Definitely check gravity loads and out of plane lateral loads. If those loads can be handled by the existing masonry, then utilizing the existing masonry will be your cheapest alternative. If the masonry can't handle it, then the steel frame will need to do the job.
Wind columns are simply columns that support the girts / horizontally spanning walls that collect the wind/seismic load and deliver it to those columns. Again, they can be the masonry if the masonry works. Otherwise, they might be steel columns installed behind or within the masonry walls.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
RE: New opening in cmu wall
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
Where did you get this information? I recently did a project where I wanted to use thru bolts but could not find any source anywhere that provided any information for thru bolt capacities in hollow CMU.
I ended up using HY70 epoxy. The contractor was not happy.
FWIW, if you are going to do it this way, you need to specify that they use rotation only mode if they use a hammerdrill. Otherwise, the back of the face shell gets blown out and reduces the bearing area.
RE: New opening in cmu wall
The rotation only mode stuff is a fine suggestion. I'll roll it into my next spec.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: New opening in cmu wall
RE: New opening in cmu wall
RE: New opening in cmu wall
RE: New opening in cmu wall