Can I "delete" an existing hole in a steel plate by filling it with a plug weld? 8

[Enginerdad]

I'm replacing an existing diaphragm on a bridge, connecting to the existing connection plate on the girder. The iron workers drilled new holes in the connection plate to align with the new diaphragm holes, but one of the holes is too close to the existing hole to meet minimum bolt spacing requirements. They're asking if they can fill the old hole with a plug weld to satisfy the minimum spacing requirements. Does AASHTO or AISC address this at all? See picture below.

 

[canwesteng]

If the hole is empty, then you can use edge distance and not hole c/c provisions.

 

[Huevo]

Guidelines for Resolution of Steel Bridge Fabrication Errors See page 6

 

[Enginerdad]

Thanks canwesteng. Unfortunately, AASHTO requires 2 bolt diameters clear space, which I definitely don't have here.

 

[Enginerdad]

Huevo,

That's exactly what I'm looking for. You're a hero!

 

[BridgeSmith]

I believe the AASHTO clear distance requirements for bearing on the edge of the hole would apply only along the line of the force. In a typical configuration, the force in this case would be close to horizontal. You may not have to do anything with the extra hole.

That said, if it's the contractor's screw-up, and being fixed on their dime, I tend to follow the philosophy of making it as painful for them as you reasonably can, so they don't do it again.

 

[XR250]

That said, if it's the contractor's screw-up, and being fixed on their dime, I tend to follow the philosophy of making it as painful for them as you reasonably can, so they don't do it again.

Hopefully, your customers won't treat you similarly!

 

[BridgeSmith]

As the 'owner's engineer', we end up always having to waste time figuring out solutions when the contractor screws something up. We've only been partially successful using that philosophy when it comes to them cutting into the girder flanges while removing concrete bridge decks. They still do it every once in a while.

 

[Greenalleycat]

Can you fillet weld an oversized plate around it (say 80x80mm) then plug weld to fill the void?

 

[human909]

Hopefully, your customers won't treat you similarly!

In some sectors half the transactions and contracts are done with a team of lawyers and contract administrators and it becomes a game of meeting the letter of your contract rather than doing a good job.

Personally I find it much more rewarding to work on projects where you all just want get a good job done efficiently. Sure there might be variations, but if that can be handled with a shake of a hand the it is far less stressful and much more efficient.

Further more the above approach can readily lead to open and flexible purchase orders. I just finished a little bit of bookkeeping. My invoice was a 2/3 of the initial estimate.

On the flipside the same client has just doubled my price on one item as he wants something else included. Final price TBA but I'm guessing I'll probably bring it down by 30% as well.

Trust goes a long way and gets you repeat business.

 

[BridgeSmith]

On a bridge girder, nearly every detail and every connection is subject to fatigue, and oftentimes an open hole is better than welding to plug it.

 

[jreit]

I second BridgeSmith's opinion. A plug weld is not the best detail to use in this situation.

Could you drill through and combine those two bolt holes into a slotted bolt hole?
Impacts on the design would need to be considered though.

Link