Inward turned channel connection

[Ipetu]

For the landing header channels in a stair construction I am always used to the having the channel web flush against the supporting wall and bolting through with Hilti anchor bolts.

However, in a current project the architect wants the channel flanges turned toward the supporting wall. Bolting in this fashion puts the bolts into bending and shear. I am not so sure this is a good situation. Please see Section 1-1 on the attached sketch.

Any ideas on how this connection can be successfully carried out?

 

[hokie66]

Box in the section of channel to receive the bolts with a plate between the flanges.

 

[Ron]

I'm curious as to why you use a header channel. We generally weld a flat plate on the end of the stringers or a vertical angle clip and bolt through the plate or the angle clip.

Outside that, I agree with hokie66...box the channel to put the bolts in shear only.

If you are close on the bending + shear, you might upsize the bolts enough to handle it. Usually the vertical shear on a stair section at the top of the stringer is low because of the angle of the stair. It pushes against the header, more than it tries to slide down from it.

 

[MintJulep]

I was also thinking of a box section - but with big holes on the side away from the wall to allow you to tighten the fasteners on the inner face of the side against the wall.

The stand-off configuration in your sketch will not be buildable in the field - the stand off will all be different lengths.

 

[dvd]

Use a piece of hot-rolled bar (or burn some plate) that matches the channel dimensions. The material will cost more, but there won't be much time in it other than boring some holes.

 

[hokie66]

dvd,

That's a mechanical engineer's solution. A structural engineer would never get away with that. On the other hand, MJ thinks like us.

 

[dvd]

I think that everyone would agree that the real solution would be to educate the architect.