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Up Topic Welding Industry / Technical Discussions / AWS D1.1 2004 clarification
- - By thcqci (***) Date 04-09-2004 18:50
Just got my copy of D1.1 2004. Looking through it to see changes and refresh my memory of some verbiage that I have not visited in a while. Of course I usually spend the greatest time in the Sections 3 through 7. Have not spent a great deal of time in Section 2. Always viewed this as mainly addressed to engineers and those responsible to send me fabrication drawings to follow.

Came across an interesting paragraph that I had not read before. Paragraph 2.6.2.1 seems to say that if we have an non-detailed column splice to perform in the shop (which we always get SER approval for), we may prep the joint to bear, as one would do for a base plate for instance, and a PJP is acceptable as long as SER approves and requirements of Tables 3.4 and 5.8 are followed. Do I interpret that correctly? I went back to research when this change went into affect and I find this change came into affect in D1.1 2002. We have always just prepped and performed CJP (as referenced in 2.6.2.2) including UT when this occurs and this could definitely be a saving in time and inspection level. Have others taken advantage of this paragraph?

As I read my new code, I may come across other clarifications or interpretations to inquire about.
Parent - By CHGuilford (****) Date 04-09-2004 20:05
That's an interesting question. I never had occasion to notice 2.6.2.1 before you asked about it.

My thought is that it has to do with the column field splice requirements as described in the AISC Manual of Steel Construction LRFD version, on page 14-11 and at M2.6 and M4.4 (page 16.1-84). Usually those conditions apply to heavy columns and depend on a solid contact between the sections to resist axial compression. Normally, there is no appreciable sideways force on those columns and it is stiffened pretty good by the rest of the structure, so a CJP isn't always needed or desired. If there were, I would think a drilled field splice would be used.

Maybe someone can shed more light on the weld requirements.

Chet Guilford
Parent - - By swnorris (****) Date 04-12-2004 13:28
It's a good idea to become familiar with Section 2, because some detailers show things on shop drawings that do not correspond with the requirements of this section. One example that comes to mind is where one detailer used a 1" @ 12" intermittent fillet weld, when 2.3.2.4 states that the minimum segments of an intermittent weld fillet shall be 1-1/2". If we as fabricators become familiar with Section 2, we should be able to catch things shown on the shop drawings or even the design drawings that are not in accordance with the requirements of Section 2, and bring them to the responsible parties attention. I am a production manager and have the opportunity to review contract documents and design drawings for pre-detailing meetings. I also look over approval drawings and drawings prior to issuing them to the shop, so I have an opportunity to change some things before they become problems.
In answer to your question, unless you're preparing the splice for field welded tier columns, I don't think the non-detailed column shop splice you're referrring to applies to 2.6.2.1. It sounds to me like you're welding two shafts together and then shipping to the field, in which case the joint should probably be CJP. To me the key words in paragraph 2.6.2.1 are "finished to bear", which indicates to me a tiered column situation and not a shop welded splice. I will say that I think PJP's (as opposed to CJP's) could be used more often than what I am seeing. I have found that some detailers simply choose to show CJP's rather than going through the time and trouble to calculate weld sizes and groove depths for PJP's.
Parent - - By thcqci (***) Date 04-12-2004 15:04
I agree with your last statement. That is one reason I was interested in PJP as opposed to CJP. You are probably correct that the main intentention of this paragraph was for tiered columns. But there could be applications other than that.

I was thinking of the occasional shop splices that are required due to pieces cut too short (I know all of you are shocked that that actually happens in other shops also!) or because a longer column was required than the current stock, but by combining 2 pieces of current stock, you could remove those pieces from inventory instead of having to buy a new piece. Of course, all those splices would be SER approved anyway and if he does not like it, it doesn't much matter.

Unfortunately, we get drawing precisely 23 minutes before the pieces are due on the jobsite so there is not really too much time for previewing drawings. And also unfortunately, we don't always have those pre- meetings as I believe we should. That will be changing in the near future as we are implementing new procedures related to AISC certification. Tightening everyone's belt a little!!!

Since I have a few slower days, I plan to spend some time reading this "most interesting" book very thoroughly. That is why I happened across it. I am sure I will find a few more factoids that I didn't realize were there.
Parent - - By jwright650 (*****) Date 04-13-2004 11:17
Hi Doug,
Columns can also be short by reasons other than saw operator error too. I have had detailers that figured the wrong bottom of base plate elevations, or was given the wrong elevations by the engineer, that caused us to splice many columns that were, in turn, detailed too short.

Do you get the shop to splice a piece on that is least a foot or more to make it easier to UT the joint, when the splice only needs to be a couple inches (particularly when the splice is at the base plate end of the shaft)?
John Wright
Parent - - By thcqci (***) Date 04-13-2004 12:37
Yes. Typically the SER specifies where to put the splice. If holes are already drilled at the drill-line, then of course that helps dictate where a splice is (easily) practical. Don't get me wrong, this does not happen often (couple times a year perhaps). Last time it happened was when an inattentive saw operator cut a column out of a 50' section when a 60' section was required.
Parent - - By jwright650 (*****) Date 04-13-2004 12:47
I wish I could say it only happened a couple times a year, congrats to your shop. I see more of these than I care to discuss in a year's time. If it's a mistake at the saw, normally it is a foot that gets cut short. They use the one foot mark instead of using the hook on the end of the tapeline and then I guess you can see how the mistake will happen if they aren't keeping their minds on what they are doing.
John Wright
Parent - - By CHGuilford (****) Date 04-13-2004 13:10
Just a side note on this. We too run into problems with holding one foot and forgetting to deduct the difference. What I try to coach people on now is to make a mark at 12" and line up the one foot mark with that, then clamp the tape.
We aren't 100% by any means (hard to teach old dogs new tricks) but there has been a reduction in errors. But I use that method myself because there's nothing more embarassing than QC making the classic "one foot mistake".
Chet

Parent - - By swnorris (****) Date 04-13-2004 13:50
The first thing our saw operators do after they look at the length on the cutting list is to write the cut length on the beam along with the piece mark, then they measure and mark it for the cut. This seems to help the cut length "stick" in their minds. Mistakes will happen, but the guys rarely cut anything wrong. Our saw operators are issued 30', 50' and 100' tapes. The 30' tape works for over half of the cut lengths, however the hooks on the 50' and 100' tapes can cause problems with an accurate length, so when they use either of these two tapes to measure and mark cut lengths, they just hook the 30' tape on the end of the beam, and mark a two inch line. Then they clamp the two inch mark on the 50' or 100' to the two inch mark on the beam, then measure and mark it for cutting. We don't hold a foot on anything because then you leave yourself wide open for someone to forget to deduct.
Parent - By jwright650 (*****) Date 04-13-2004 14:32
Hi swnorris,
I agree with using the 2" or the 12" mark to help avoid that, as Chet said, "embarrassing mistake". Which ever increment you use, the numbers get worn out in short order. So maybe alternate where you mark and align the tape and clamp?
John Wright
Parent - - By jwright650 (*****) Date 04-13-2004 13:51
Hi Chet,
Our fitters and shop inspectors use the very method you described and they have a better success record of avoiding the "one foot mistake".
John Wright
Parent - - By TimGary (****) Date 04-13-2004 14:49
Just yesterday, we cut a beam twice and it was still too short...
Go figure...

:) Tim
Parent - - By thcqci (***) Date 04-13-2004 15:59
In our shop, fitters can't take all the credit for the high success rate of cutting beams, girders and columns to length correctly since we have a Peddinghaus drill/beam line that cuts the majority of them. Unless the data is entered into the computer wrong (which has happened), an 1/8" variance is the most we normally see.

The last couple of times we had a problem was from saw operator error in choosing material length. One time he trimmed ±3" off a 50' raw length column that was supposed to be a just a bit under 50' and did not have enough at the other end when it came through to trim the other end. Stuff like that is far more the problem than cutting-a-foot problems. Normally there is supposed to be someone, other than the fitter, double check something before it is flame cut to length if it is anything of a major piece.
Parent - By vonash (**) Date 04-14-2004 21:46
Column slices may be made with PJP welds as specified. Slices in other structural steel members, either primary or secondary, require full penetration welds. Of course the responsible engineer/owner may designate otherwise. If they do, all procedures, techniques and personnel must be qualified in accordance with AWS D1.1.
Up Topic Welding Industry / Technical Discussions / AWS D1.1 2004 clarification

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