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Adding On To Mislocated Column

Adding On To Mislocated Column

Adding On To Mislocated Column

(OP)
I have a few concrete columns that were poured from 3" to 10" off from their specified location at their lowest level (footing also off by same amount) due to some issues with the surveyor. They are only off in the x direction.

The contractor does not want to chop and replace. As an alternate to removal they would like to add on to what is there. Any issues with this?

My initial thoughts:
- I don't want to add a few inches, so I'm thinking of a 12" min. width that is reinforced and tied like an independent column. In addition to the closed ties I will drill into the existing column to brace 12" to full column.
- I need to drill and develop the new bars into the footing.
- There are interior and 'short' columns, no appreciable unbalanced moment.
- I will end up with original size/reinforcing + a scab that is 12" x column height so much more overall area and reinforcing.
- I do not see the two as needing to act compositely

You'd end up with the column above sitting say 80% on the 1st placement column below and 20% on the new 12" column that is braced to the 1st column.

Any issues?

RE: Adding On To Mislocated Column

Probably OK for the column, but the footing is still an issue. My preference would be to bend over the column bars, hook a mobile crane up to them, and lift the whole thing out. Done it in the past without objection from the contractor who had screwed up.

RE: Adding On To Mislocated Column

Can that bay just be a bit bigger and smaller architecturally?

RE: Adding On To Mislocated Column

(OP)
hokie - I can't do that here. These are buttresses that are built integral with basement wall. They are columns above but because of geometry are close enough to the wall that they are integrated as buttress of the wall. It would have to be cut off from the wall and new column joined back in. They are interior columns though - the basement is set in, i.e. not at extent of building above.

RE: Adding On To Mislocated Column

(OP)
and in terms of footing eccentricity I'm not that worried. They are huge footings and the actual misplacement relative to the overall buttress size only shifts the centroid a very small amount.

RE: Adding On To Mislocated Column

Fair enough. I had assumed isolated pad footings. In your case, adding on to the columns should work fine.

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