Precast planks @ New WF BMs
Precast planks @ New WF BMs
(OP)
I am reviewing shops for a project designed by another engineer. The floor framing is precast planks sitting on support inside the web of the W30 bms (I hate always hated this detail). The precaster is asking if he can cut off about 4'-6" portion of half the top flange to slip in his planks and then he would weld flange back on. I can't see any other way for him to be able to install the planks but I am very nervous about how to approach this. If I give him the go ahead, I am going to ask: 1) The bm be shored until the work is done, 2) Cut the flange starting about a 1' from the end of the bm.
But how on earth is he going to restore a full pen weld when there is plank on one side of the flange? Has anyone run into this issue before.
Thanks,
But how on earth is he going to restore a full pen weld when there is plank on one side of the flange? Has anyone run into this issue before.
Thanks,
Kaiser






RE: Precast planks @ New WF BMs
I do not like the idea of messing with the flange though...
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Precast planks @ New WF BMs
Did this concern get raised before this system was chosen?
RE: Precast planks @ New WF BMs
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Precast planks @ New WF BMs
RE: Precast planks @ New WF BMs
I take it that you have already considered sliding them in from the ends.
RE: Precast planks @ New WF BMs
The method of installation also needs consideration. I seen alot of beams twist dangerously when only loaded on one side.
Kieran
RE: Precast planks @ New WF BMs
Hard to tell as you have not given any info on spans
RE: Precast planks @ New WF BMs
http://www.peikkousa.com/Default.aspx?id=536463
We welded a ledger plate to the bottom flange of the beams on one project, and I worried about that detail for a long time. It worked out fine, but I really hated the detail.
Brad
RE: Precast planks @ New WF BMs
RE: Precast planks @ New WF BMs
What fills the gap between the top of plank and top of beam? The W30 is fairly deep.....Is the top flange of the beam unbraced the entire length?
RE: Precast planks @ New WF BMs
Like I mentioned before, the orignal design was by an engr. who left the firm. I never like the idea of planks spanning into the side of the beam. The one good thing I see in the detail is that for plank bearing, an inverted steel angle welded to the beam is being used. So in essence I have two small tubes with in the beam, which makes me feel better for the any twist issues.
I am going to ask:
1) The beam be braced until the installation of planks and repair of the top flange is done.
2) Cut the flange starting 1' from the end of beam.
3) The precaster to provide a detail of how he is going to have the steel fabricator re-weld the flange and I'll suggest use of a pre-welded backer rod.
In response to some of the questions: The beam is braced by planks on each side. And no this was no my design, the kid engineer did not put a lot of thought in to who this was going to get built.
Kaiser
RE: Precast planks @ New WF BMs
If the panels are hollow core, you could grout the ends to form a composite section with the beam, using a smaller W beam so you can bear the panels on top of the WF (with headed studs of course).
Or a concrete girder, with L's cut out of each side at the top to form a ledge for the panels?
Yep, someone did not think this one out as we all can see....
RE: Precast planks @ New WF BMs
Kaiser