Diaphragm to CFS Shearwall Transfer

[Struct_EIT]

I am trying to design a steel framed building with moment frames in one direction, and cold-formed steel (CFS) shear walls in the other direction. The building has a tall parapet that wraps around the entire building. This is a single-story building. I am wanting the CFS shear walls to bypass the steel framing to create the parapets. My question is how does the shear forces from the diaphragm get transferred into the CFS shear walls? I have attached a sketch to show what I am talking about.

Will the detail simply involve CFS blocking between the studs at the diaphragm elevation, and then the blocking fastened to the edge angle of the roof?

What would be the height of the shear wall? Would it be the full height from the slab to the top of the parapet, or from the slab to roof elevation (where the force is applied).

I feel like this is a pretty common scenario, any documentation regarding this scenario would be appreciated.

 

[phamENG]

The issue here is that, to make that work efficiently, you're going to turn it into a bearing wall. That beam will serve no purpose. Typically you'd have a deflection clip from the beam to the wall so the beam can deflect without loading the wall studs. The issue is that most of those don't transfer shear very well. Transferring shear without axial load is doable, but usually dubious and I'd still design the studs to take a good chunk of what you think the beam is taking.

 

[Struct_EIT]

@phamENG, thank you. I was curious about that as well. The bar joists do not bear on that beam (they run parallel to these shear walls, and bear on the perpendicular moment frames) and leaving the load on that beam minimal. Thank you for your input.

Is there a better option of framing the walls than using bypass? Would it be more efficient to frame the studs to the bottom of the beam? if I did that, then the parapet will require bracing back to the roof structure because it gets up to about 6.5ft tall.

 

[phamENG]

That's an option. 6.5' is a lot...can your 6" stud handle that on its own anyway? You may not have a lot of axial load, but a tall, slender stud with a tall cantilever parapet doesn't need much axial load to buckle it.

I've also done an angle fastened to the side of the load bearing studs with clips to catch the deck as it comes over.