is it acceptable to join two beams for material lenght usage? 2

[C. Hirata]

Hello, first time here, we have this project and a supervisor told our people that a beam, HSS 14X6X1/2, should be continuous, without any welded tie, this would result in large material waste, and as far as I know, there is no code that avoid this welded tie, but I'm dubious, is there any code or specification about his issue? (Fyi. I read the client drawings and it doesn't specify against this condition)

best regards

 

[phamENG]

From your post I understand that you're dealing with a beam, it's made of steel, somebody wants to weld something and somebody else doesn't.

That's really not a lot to go on.

 

[HTURKAK]

Dear C. Hirata ,

As far as i understand, the question is for welded splice of HSS beam. I do not know the applicable code in your region. Welded splice could be an option but the splice location should be around L/4 . 8 far from max. shear and moment..)

When the splice is for tension elements ( chord of truss, bracing etc..) the requirements are more stringent .

Check your code for the inspection requirements of butt welded joints.

 

[C. Hirata]

I understand it is posible to join two HSS beams, using a butt welded joint or maybe another prequalified welded procedure, but there is a code against it? I mean in the AISC or local code you may know, where it could say that "under X condition you should not join two beams"

 

[rb1957]

Where are you, so we have a chance to understand which code is applicable to you ?

It wouldn't matter (would it ?) if the code in some other region disallowed this if the code in your region allows it.

another day in paradise, or is paradise one day closer ?

 

[C. Hirata]

building is located in Texas

 

[dik]

It's common to weld members to make them longer or to reduce waste. You need a CJP weld that is nicely done. The matter isn't the code, but some specifications specifically exclude welded joints unless approved by the EOR... you have to check. Unless a visibility issue, there should be no concerns. I should clarify that a bit... I don't know of any codes that exclude splicing.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[C. Hirata]

yes, I thought it was an odd comment from the checker, since I hadn't hear against this practice, I have to say I'm not even in the US, but as far as I know if the process is on paper and qualified, and the welding itself pass through any applicable test, beam continuity is ensured, visually is a questionable issue since it won't be a visible beam, but that would be a matter far from structural, as I understand.

 

[skewl]

If you needed a complete penetration weld for the continuity, I am not sure how you can achieve that in a HSS beam? My knowledge is that you need to weld from both sides or it is not really a "complete" penetration (i.e. with a bevel groove weld the tip of the bevel would be damaged during welding and you won't get a complete penetration weld).

 

[jayrod12]

You put a backer plate on one side of the HSS on the inside, and then bevel the second piece. There's ways to provide a CJP weld from one side only.

 

[Brad805]

We have millions of miles of underground pipelines that suggest a full pen is possible. With proper prep, you lay a weld as you burn thru that bevel. It takes skill. I watched my father do it a ton and every weld is tested or it was in his era. It is not how we structural guys do it.

 

[skewl]

jayrod12/Brad805,

I suppose I was just grasping at straws to find a reason why the checking engineer was advising against a welded splice. I was designing a plate box girder (for a bridge) recently and we had to go through a significant effort to find ways to allow welding from both sides. I think a backer plate was out of the question for us here due to fatigue reasons.

 

[KootK]

1) I agree that there's no code prohibition on field splicing members with welds.

2) In most building applications, I'd think that you'd be better off with fillet welded flange and web plates. Quality control on full penetration welds made in the field can be problematic for folks who don't do that kind of thing on a regular basis.

 

[dik]

So, who's inside the pipe? and how does he get out?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[ThomasH]

Hi

I wouls say that there a several acceptable ways to weld two beam parts together. I am not in the USA but I have seen it done in several countries, including the USA. The only apparent issue I can think of is if there is fatigue loading involved. That can limit the available options for the detailing but it should still be possible.

Thomas

 

[BridgeSmith]

I agree with the other posters that it is possible, and that it must be detailed carefully, especially if fatigue is an issue.

However, it may not be worth it - steel is cheap and getting skilled and certified welding done is expensive. On bridge girders, we would only consider a welded splice if it saved more than 5000 lbs of steel, since that is about the break-even point when the cost of welding and inspection of the weld are considered.

Rod Smith, P.E., The artist formerly known as HotRod10