Splice of combination section

By swnorris (****)

Date 02-21-2008 12:04

I'm not sure I understand your description without looking at a sketch, but it doesn't sound familiar to me. Is this on a fabrication drawing, or is this something that the fabricator would need documented approval from the EOR to do this? If it's on a fabrication drawing, it should be able to be referenced to a section on a design drawing. Maybe you could look at that and see what the design intention is. I've sometimes found that what the design drawing shows and what the fabrication drawing shows are two different things. I know there's more than one way to do things and still get the same effect strengthwise, but sometimes the detailer grossly misinterprets the design intentions, or the fabricator just decides that something is too costly and opts to take an unapproved shortcut.

By Duke

Date 02-21-2008 13:35 Edited 02-21-2008 13:40

Sorry for the pathetic rendition, no this splice is not detailed on the design drawings, fabricator is going rogue on this. They may not have begun fab yet, this is just what I hear from the foreman.
I'm trying to head problems off, told them they need approval, I think they are after forgiveness, and I doubt that the EOR is going to buy it.

By swnorris (****)

Date 02-21-2008 14:16

Now, that section looks familiar. It sounds a bit unorthodox though. They'll have to submit a very detailed splice detail to the EOR for approval. Rogue fabricators usually go hand in hand with forgiveness. I wouldn't trust 'em as far as I could throw an elephant left handed.

By hogan

Date 02-21-2008 15:09

i have seen this design before. as far as ndt it can be RT'd or UT'd from face a and b both sides of the weld.

By eekpod

Date 02-21-2008 16:52

They are going to have to include rat holes so that the flanges can be full pen'ed with either a backing bar, or backgouged. We had to do something similer onetime. In your case, we cut the channels back about an additional 1/4-3.8" back from the bevels of the flanges. This way we new the flanges were welded 100% without and problems, then we used the new weld and filled in the gap between the faces of the channels. Granted the root opening from channel to channel was bigger than normal but I'd rather have a excellent weld in the flanges and then worry about buttering up the channels until they were within tolerences. I would also add that this is not a normal situation. Chris

By JA

Date 02-23-2008 12:52

why can't you just put the beam back together in the field without the channel , then add the channel afterwords.......if you have to cut the channel in half also to ship it , put a nice bevel on it , splice the beam,,, splice the channel,,,,,,add the channel, ,seam weld it on,,,,,,,,,done........and alot cleaner.........

By 803056

Date 02-23-2008 20:42 Edited 02-23-2008 20:49

This should be referred to the engineer of record for review. Many engineers will not permit main members to be "spliced" in the shop or the field without approval.

This type of built up member is often used for beams that support the rails of bridge cranes. If that is the application, they are subject to cyclic loading and they would have to be designed as such and inspected as such. It is typical practice to remove the backing used in CJP welds that are subject to cyclic loads. In this case, that is not possible. The faying surface between the top channel and the wide flange beam will act as a stress riser and can initiate a crack. That is never a good thing.

I would not be surprised to see the EOR required volumetric NDT of the welds. A difficult operation given the joint details you have provided.

Best regards - Al

By Duke

Date 02-26-2008 23:20 Edited 02-26-2008 23:22

I called the EOR who said he will accept cjp flange splice/ bolted web splice on the W, and he really doesn't care about the channel being spliced, and he'd send an approved detail. I really thought they were going to get their tail in a crack on this one....
and yes everything over 5/16" gets UT