Anchor Bolt to Base Plate Weld
Anchor Bolt to Base Plate Weld
(OP)
I have a situation where the contractor has set the anchor bolts for a base plate in a 9" by 9" grid vs the 13" that it was supposed to be. I have checked the anchor bolts and have determined that it can still work as long as we expand the base plate some to increase the moment arm (these base plates are resisting moment).
The issue is attaching the base plate to the anchor bolts. With the column being an HSS 10x10, the bolts will be directly underneath the column. Our idea is to cut the bolts so that they are beneath the top of the base plate and weld the anchors to the plate thus creating a flush top of plate. The question I have is, is this even possible to weld, and if so, what kind of capacity can I realistically expect to achieve? The other solution we have involves post installed anchors with a larger base plate. Our client has asked for us to look into less expensive methods of fixing this issue.
The issue is attaching the base plate to the anchor bolts. With the column being an HSS 10x10, the bolts will be directly underneath the column. Our idea is to cut the bolts so that they are beneath the top of the base plate and weld the anchors to the plate thus creating a flush top of plate. The question I have is, is this even possible to weld, and if so, what kind of capacity can I realistically expect to achieve? The other solution we have involves post installed anchors with a larger base plate. Our client has asked for us to look into less expensive methods of fixing this issue.






RE: Anchor Bolt to Base Plate Weld
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RE: Anchor Bolt to Base Plate Weld
RE: Anchor Bolt to Base Plate Weld
another option may be to set a standard base plate for the rods at 9", then have a spacer/jumper plate that attaches to a main base plate for the tube steel. the spacer/jumper is thick enough to allow for the nut, then the other plate is field welded to that assembly.
RE: Anchor Bolt to Base Plate Weld
Or have the contractor re-do the footing with the correct anchor layout.
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RE: Anchor Bolt to Base Plate Weld
If the anchor rods already in place, I don't see how the welder would be able to make that weld to the underside of the base plate. What sort of clearance would he have to get in there?
Why not just use post installed anchors at the correct location (13" grid) instead?
RE: Anchor Bolt to Base Plate Weld
RE: Anchor Bolt to Base Plate Weld
CBSE, that was one option I had considered, but I'm not sure you could fabricate a plate with a beveled hole. Our thought was to have the bolt extend halfway into the plate, square weld the anchor bolt on the side to the plate all around and then fill in above the anchor to the top of the plate with a puddle weld.
I agree that this is not the most ideal situation, and I could just tell them they have to use post-installed anchors and deal with the cost of it, however I feel like it is our responsibility as engineers to look at all the possible solutions and come up with an efficient and creative fix for the problems we encounter.
RE: Anchor Bolt to Base Plate Weld
RE: Anchor Bolt to Base Plate Weld
I'm envisioning something like a short section of HP sandwiched between two plates -- one to match the AB pattern, one to match the base plate pattern.
I also have concerns about the quality of any weld in the dirt, especially if you're talking about halfway down some sort of square hole.
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RE: Anchor Bolt to Base Plate Weld
Could you introduce a secondary plate which accepts the anchor rods at the 9" grids and also provides attachment points for a separate set of bolts at the 13" grid. Note that your moment due to eccentricity with this connection would be increased.