STEEL BEAM ATTACHMENT THRU EXPANSION JOINT TO STEEL COL

[RDMESH]

Hi all,

I ran into a situation where steel beam runs through the expansion joint at the end of exterior walls and frames into the steel column located beyond expansion joint. I do not see any guidelines or detailing options mentioned on AISC. Anyone ran into this situation? See attached sketch. I always two rows of columns on either side of joints but this is odd ball case I had to deal with. Any detailing suggestion is really appreciated.

Thank you,

RD

 

[KootK]

Your detail is about what I'd expect. A couple of minor points that you've probably already considered:

1) Make sure that something at or near the beam bearing is providing rotational restraint to the beam.

2) I'd be inclined to stiffen the seat. You don't want to see much deformation in something intended to allow movement.

 

[hokie66]

One potential problem with this type movement joint is noise, particularly if this is a residential or commercial building. When a sliding joint moves, the built up friction is released, often resulting in a sound like a rifle shot. If you do use a sliding joint, make sure the maximum travel is accommodated, and also that the supported member cannot move upward or sideways.

 

[JAE]

Typically with a teflon type bearing system - you would have something like the following:

Upper plate assembly
(top to bottom)
Steel plate bonded to
Teflon pad

Lower plate assembly
Teflon pad bonded to
Steel plate bonded to
Elastomeric pad set on
Bearing Seat Plate

The upper assembly is sized larger than the lower assembly so that when the beam moves back and forth the lower plate surface is never exposed to collect dust, debris, etc.
The elastomeric pad allows the beam to flex a bit and thus minimize gouging in the teflon pads along their edges.

Usually you see long slotted holes in the bottom flange of the beam to afix the beam to the bearing seat with loose bolts. (i.e. not quite snug tightened and fixed so nuts don't back off).

 

[KootK]

Sample detail of a similar vein to what JAE has thoughtfully described.

 

[msquared48]

Additionally, I would add a single knife plate welded to the column with horizontally slotted holes to help laterally fix the flange of the beam.

Mike McCann, PE, SE (WA, HI)

 

[RDMESH]

Thank you guys for your input. The movement on the beam will be both in plane and out of plane. With long slotted holes in angle in plane movement is achieved but for out of plane movement would you do horizontal slots in column to angle attachment as well? My big dilemma is how to allow out of plane movement in steel beam.Please let me know your thoughts.

Thank you!

RD

 

[JAE]

I think I've seen two-way teflon bearings before, but rarely do they work in my view.