Interior CMU Partition Wall
Interior CMU Partition Wall
(OP)
Hi All,
I am currently designing CMU partition walls (non-load bearing) that are 16' high, for an existing building in Puerto Rico. The architect has proposed a steel support frame for behind the walls to provide bracing at mid-height and the top of the walls, see attached image. The length of the long wall is 30' and the short wall length is 6'. The only loads that I anticipate for these walls are their own selfweight, a live load of 5 psf and their seismic loads (SDC = D). Due to the walls being installed in an existing building, I would like to reduce the amount of loads induced on the existing structure as much as I can. Therefore, I would like to avoid attaching the walls to the roof and to consider the connection at the bottom of the wall as pinned. I am planning on using either 8" or 10" block.
My question is, would I be able to eliminate the steel frame and be able to use just bond beams at the top of the wall and mid-height to provide enough stability for the wall? I.E. for in-plane loads, design the wall as a two story shear wall with the bond beams acting as the chords to distribute the shear force into the wall, and for out-of-plane loads, consider the bond beams as simple supports for the walls.
I hope I explained myself clear enough. However, if you have any questions or need more clarification feel free to ask. Any and all suggestions will be welcomed. I am a little green when it comes to designing w/ masonry.
Thank you for your time,
Mike
I am currently designing CMU partition walls (non-load bearing) that are 16' high, for an existing building in Puerto Rico. The architect has proposed a steel support frame for behind the walls to provide bracing at mid-height and the top of the walls, see attached image. The length of the long wall is 30' and the short wall length is 6'. The only loads that I anticipate for these walls are their own selfweight, a live load of 5 psf and their seismic loads (SDC = D). Due to the walls being installed in an existing building, I would like to reduce the amount of loads induced on the existing structure as much as I can. Therefore, I would like to avoid attaching the walls to the roof and to consider the connection at the bottom of the wall as pinned. I am planning on using either 8" or 10" block.
My question is, would I be able to eliminate the steel frame and be able to use just bond beams at the top of the wall and mid-height to provide enough stability for the wall? I.E. for in-plane loads, design the wall as a two story shear wall with the bond beams acting as the chords to distribute the shear force into the wall, and for out-of-plane loads, consider the bond beams as simple supports for the walls.
I hope I explained myself clear enough. However, if you have any questions or need more clarification feel free to ask. Any and all suggestions will be welcomed. I am a little green when it comes to designing w/ masonry.
Thank you for your time,
Mike






RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
1. cantilever design (pilasters possibly) if foundation feasible
2. bond beams supported at ends via a connection to the existing. 30' seems problematic for a normal bond beam.
3. steel frame to support simple masonry design
Each has pros and cons that I would judge based on trade availability.
RE: Interior CMU Partition Wall
Brad805, when you say a connection at the end of the bond beams, what exactly did you have in mind?
RE: Interior CMU Partition Wall
If you need to close off the space between rooms for sound or air flow reasons then provide drywall between the top of the masonry wall and the structure above.
RE: Interior CMU Partition Wall
The steel frame is an easy solution, but it is not without its own little problems. That top beam will need to be connected as well unless you have a moment base connection. I suspect the all masonry solution will be an easier option to detail and avoid steel shops, but either options work.
RE: Interior CMU Partition Wall
Mike McCann, PE, SE (WA)
RE: Interior CMU Partition Wall
Jike, that's a great point you bring up about the "required" height of the wall. If I am able to reduce down that height, it will definitely make things easier on me. The roof is made up of prestressed double tee beams, so I want to try and avoid inducing any unnecessary forces on them.
Msquared, I like your idea with the 10" wall and steel struts to brace the beams. If I do find that the bond beam is insufficient and needs additional capacity, would you suggest that I use a C-Channel turned on its side to "straddle" the wall?
RE: Interior CMU Partition Wall
1) Double tees are heavy and will generate large seismic diaphragm loads on their own. The extra load that your wall will add won't affect the system much.
2) If your support frames will be attached near the tops of your columns, as shown in your sketch, the lateral loads on the wall are going to wind up in your roof diaphragm no matter what. And adding transverse seismic loads to columns is generally undesirable.
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: Interior CMU Partition 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: Interior CMU Partition Wall
Yes. A channel could work well, depending on the connection used for any horizontal struts.
Mike McCann, PE, SE (WA)
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
Mike McCann, PE, SE (WA)
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
Mike McCann, PE, SE (WA)
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
Sorry for any confusion.
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall
RE: Interior CMU Partition Wall