LATERAL FORCE @ EXPANSION JOINT FRAME

[LOKSTR]

I have one rectangulat steel building frame( single storey) with one full width expansion joint that divides the building into lengths "L1" & "L2".

My 3 nos. braced/moment frames are located at each end(frame 1,3) of building and at expansion joint(frame 2).

My concern is :

How the lateral wind/seismic(parallel to expansion joint) will be distributed at the expansion joint frame(frame 2)?
Will it take lateral force contribution from length "L1" only and nothing from length "L2"?

In other words will the frame-3 at end will have to take all the lateral force contributed by "L2" and frame 1 & 2 will take lateral force from "L1" only?

There is only single column at expansion grid with sliding beam connection.

Thanks

 

[AggieYank]

It isn't a true expansion joint as you have explained it.

A three frame long building with an expansion joint right next to the middle frame. That doesn't work. You'll have to add an additional frame next to your middle frame such that you'll have two buildings, with a frame at each end. To be a true expansion joint, the buildings have to be completely separate. Basically, if one building was completely taken apart and removed, the other building would still stand and be structurally sound.

I'm just guessing, but usually if a building only needs three frames, maybe it doesn't need an expansion joint at all. 200-300 feet is a decent standard, depending on the materials, and your experience.

 

[LOKSTR]

AggieYank,

The building is 700' long, so an exp. joint( approx. 8" wide) is reqd. So, I should take 2 frames on each side of exp. joint and then treat it as 2 separate buildings on each side of exp. joint. Is this what you are trying to say?

Thanks,

 

[AggieYank]

That is correct LOKSTR. The architect should show some sort of flashing or expansion joint cover, but structurally, treat them as separate buildings.