HSS Lintel CMU Wall Bearing/Reinf Detail

[bookowski]

I have short (in plan) cmu piers that are resisting lateral load, about 4ft long in plan. Openings are 12+ ft but carry only about a 3ft band of masonry, so little load. The contractor wants HSS lintels. Is it reasonable to have holes in the top/bottom of the HSS, have it dropped down over the end cell vertical reinforcing, and to show an internal form/blockout and the end grouted. If I don't do that then the effective wall size shrinks quite a bit relative to my overall size. They'd have to locate the holes based on the field placement of the bars which is a pain but doable.

 

[BSVBD]

Can you provide a detail of what you are talking about?

 

[KootK]

Sounds pretty finicky to me. If I understand correctly, these are 4' x 15' cantilevered shear walls. Do you really care if you loose a couple of cells at the 12' level? I wouldn't. Or are you trying to use the 3' band as a moment frame beam?

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.

 

[KootK]

Alternately, you'll probably have a bottom plate in the HSS. What if that ran over the CMU but the HSS itself did not? Throw a generous slot in the plate over the bearing and you should be good to go.

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.

 

[KootK]

I probably guessed the wall height wrong. More like 4' x 8' piers with 3' band above I imagine. Same answer still.

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.

 

[bookowski]

4' long piers in plan, few stories high with story heights from 10' to 12' - so yes cantilevered, although all shear walls are cantilevered at the end of the day. Window openings are 12ish feet and not trying to use the cmu as a moment frame - this idea really interests me but I've never had the guts to do it. If I assume I lose 8" each end for a cont bar then my wall effectively drops to 32" from 48".

I agree it's very finicky, although it's the type of job where they will deal with it if that's what I show. Or at least attempt to. Offset plate isn't bad, I could get 4" of bearing from hss onto plate and then say another 4" of plate with opening for bar pass through. The bearing stress is next to nil.

Anyone ever use these? Look pretty cool, kind of what I am attempting to diy.

 

[KootK]

I've never tried the Power Box things but I've been curious too. What's your width of wall and width of lintel here?



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.

 

[bookowski]

8" CMU, 8x8 tube lintel.

 

[KootK]

In that case, I love the DIY power box concept.

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.

 

[bookowski]

I'm going to give it a shot. I'll post a photo if it works. Might make the slot a slotted hole though to provide a positive engagement/axial path just for fun.