Clarification on Using AWS D1.1 5.26.5 to Repair and Redrill Misaligned Holes 1

[MegaStructures]

From AISC.org

"Generally, mislocated fastener holes are not detrimental to the strength of a member if the remaining effective net section is adequate for the loads. As such, they may be left open or filled with bolts. If required, mislocated holes can be structurally repaired in accordance with Clause 5.26.5 of AWS D1.1. Attention should be paid to the Commentary to Clause 5.26.5, as it describes a rather involved process that can be used for such repairs. The process involves considerable gouging and welding, and therefore considerable heat input. As with all repairs, the benefits of the repair should be carefully weighed against the potential problems that the repair itself could cause. Plug welding of mislocated holes is not an acceptable structural repair. If a bolt hole is mislocated by a small amount—say, less than a bolt diameter—it is often possible to adjust the connection material to accommodate the error."

I have holes that are misaligned by ~0.5D that I would like to repair and re-drill. My understanding from this excerpt is that this is allowed per AWS D1.1 Sec 5.26.5 if the correct welding procedure is used and a typical plug weld is not the correct welding procedure.

Also AWS D1.1 calls out that the soundness of the restored base metal should be verified by the NDT methods specified in the contract document for examination of tension groove welds as approved by engineer. I am not requiring NDT of groove welds throughout the project, so does that lift the requirement on NDT for this repaired base metal? Do other recommend an NDT examination on these anyway?

Otherwise I can revise my current bolted-bolted double angle to a bolted-welded double angle. Then my question is what do I do with the remaining holes that were originally misaligned? I would prefer to plug weld them and not worry about the reduced section modulus, but per the above recommendation I don't think I am allowed by AISC to consider the full section with plug weld repairs only.

Edit: Steel is not quenched or tempered. Standard A36 rolled steel

 

[r13]

To where the misaligned holes occurred - column/beam web/flange, connection plate..? How many holes? Vertical offset or horizontal offset?

 

[HTURKAK]

IMO, the plug welding is not acceptable for the connection of misaligned bolt location but, filling the misaligned hole with plug welding and redrilling at correct position should be allowed and this is common practice.

However, plug welded connections are not permitted on some steel types but not for Standard A36 rolled steel.

If the amount of misalignment small , the common practice reaming of the hole with reamer diameter equal to hole size. But this process eventually slotting the both clamped plates.

 

[r13]

If the amount of misalignment small , the common practice reaming of the hole with reamer diameter equal to hole size. But this process eventually slotting the both clamped plates.

Weld a stopper bar maybe work.

 

[MegaStructures]

HTURKAK I want to make sure I understand your opinion.

IMO, the plug welding is not acceptable for the connection of misaligned bolt location but, filling the misaligned hole with plug welding and redrilling at correct position should be allowed and this is common practice.

How I interpreted.. Plug welding is not allowed to connect the two elements i.e. filling the hole of the double angle with weld instead of a bolt, but plug welding the hole and then redrilling is acceptable.

My addtional $0.02 - Per AISC plug welding should still not be accepted, but the approved procedure shown in AWS D1.1 should be used

You went on to say

However, plug welded connections are not permitted on some steel types but not for Standard A36 rolled steel.

A36 steel is not heat treated, or tempered, so plug welding is permitted.

“Any idiot can build a bridge that stands, but it takes an engineer to build a bridge that barely stands.”

 

[HTURKAK]

Dear MegaStructures ;

I looked AWS D1.1 and specially to Clause 5.26.5 .. moreover I copied and pasted below;

Yes ..you understand my opinion .. I have used the term PLUG WELDING may lead to misunderstanding ..I just want to say depositing /filling with weld material with welding operation of the wrong drilled hole .

I am more familiar with Eurocodes.. This morning looked to web and found the following document which is more stringent than simple snug tight connections.

Pls look to the item rectification of misaligned holes..

https://www.steelconstruction.info/images/1/16/GN_5-08.pdf