Offset HSS Header Connection Detail

[Galambos]

Im looking to improve my offset header connection details, and wondered if anyone had one for a condition where the curtain wall remains continuous past a column (hss or wf).

by offset, i mean the centerline of the hss header (lintel) is set a distance away from the exterior column line.

thoughts?

 

[rscassar]

If the connection is hidden above the ceiling then I would provide flat plate or angle cleats.

 

[BAretired]

Galambos,

It might help if you posted a sketch of your current detail. Then we could suggest improvements.

BA

 

[Galambos]

I have uploaded the detail. Please note that i have to keep the area below the HSS clear for storefront that bypasses the columns.

I'd appreciate your input.

 

[ToadJones]

I have done this same thing mainly two ways many times on industrial buildings in order to support wind columns that were over top large door headers.

1). moment endplate connected outrigger with the header siting on top of the outrigger with a small tie back atop the header. Wind column would be somewhere near midspan sitting on the header

2)moment endplate connected outrigger with the header spanning between the outriggers simple span. Wind column would be somewhere near midspan sitting on the header

For your situation, option 2 here is probably more suited.
I like the endplate moment connection better than your detail.

 

[Galambos]

Toad, thanks for the response. im trying to picture a moment endplate connected outrigger. it sounds as if the outrigger and the hss are one shop assembly. can you elaborate?

 

[msquared48]

I understand the purpose of the angle 2X2 at the top of the tube section - to resist the induced torsion - but I would feel better with an angled gusset there. Seems flimsey to me by my gut reaction.

Mike McCann
MMC Engineering

 

[ToadJones]

Worst sketch on Eng-Tips for 2011

 

[ToadJones]

Sketch is just one way I have done it.
Other way is with the header spanning (into page) b/t outriggers on columns on either side of opening.
Also, I didn't show the tie-back on top of the header, which I use to resist torsion caused by wind loading on wind columns that rest on the header

 

[msquared48]

Toad:

OP said he can't have anything below the HSS section. Did you intend the section detail as upside down?

Mike McCann
MMC Engineering

 

[Teguci]

Bolt or field welded options. Just some thoughts to keep the complicated stuff in the fab shop.

 

[ToadJones]

M^2
Yea, I guess you could "hang" it.
But, if the header spans between outriggers than you could make it so that nothing is below the outrigger.

 

[Galambos]

ive been trying to justify the load on the side of the hss wall using my detail. im thinking it's a similar limit state to K1.5 and i should be fine.

I have cases ranging from vertical Vuy=2k for an HSS6x6 to 18k for an HSS20x8x3/8. I also have Vux=1.5 to 8k.

Hmmmm....

 

[BAretired]

I think I prefer an HSS stub projecting out of the offset header. The stub would have an end plate bolted to the flange of the column. The header, stub and endplate would all be shopwelded together as one assembly.

If my description is not clear, I could provide a sketch.

BA

 

[hokie66]

Agree with BA about shop welding the outrigger to the header. But I would assume that there are headers each side of the column. Using his suggestion, you could cantilever the header past to pick up the next one.

My solution would be just to project a plate out from the column, and use end plates on both headers, bolted to the projected plate. All that site welding could be avoided.

 

[ToadJones]

BA-
I think you are more or less describing the same thing that I am only mine was all bolted.
You're idea is probably better.
In the end, it's still an endplate moment connected outrigger.

 

[BAretired]

Agree with hokie. If the column spacing is not too great, you could use two or three span headers with cantilevers to pick up the next ones.

Sorry Toad, I missed your concept.

BA

 

[Galambos]

hokie, you are correct. there are two headers framing into column.

i like your idea of the endplate and bolting together, however, the two headers frame into the same outrigger and i think that would cause erection problems where the bolts are shared.

BA - good idea, however, hss lengths have already been ordered.

i also have conditions at the corners where the hss needs to continue past the column to cantilever a short distance to the building corner.

right now, i think i will use a W shape outrigger with a welded single angle conn with flange plate top and bottom to restrain the hss. im thinking that i can get away with a 1/4"-3/8" plate on the bottom.

 

[ToadJones]

Well, the erection problem of Hokie's idea can be deal with using offset hole patterns in the connections.
This is done often for clip angle beam connections in a shared column web.

 

[Galambos]

Well, for what it's worth, this is what i ended up with.

the bottom tie back could probably be done a little better to allow for fitup.

Missing a few callouts and welds on this prelim version, but you get the point.