Column Deviation From its Position

Who made the mistake?

Would knowing make the answer to the question easier?

Yes. Please follow the link in Del's post #4

Contractor made mistake then need attention of consultant

"Contractor made mistake ..." - then it's the contractor's responsibility to fix it.

Rip it out and replace it.

It's a bit like this thread...
If all else fails, try doing it to the spec.
Del

Let it protrude 75 mm ( if its not in your neighbours land). adjust column section for added span of 75mm.

usual disclaimer applied.

You might begin by telling us how big the column is.

Does the 75mm represent 1% of the column dimension or 75% of the column dimension?

Column size is 500X500 and column was supposed to set up at the centerline of gridline .Now is out of position by the deviating of 75 mm.This is at Raft foundation level.What is the way forward to correct problrm like that.

Best regards.

Given the information provided so far:

- 75mm out of tolerance

- 500x500 post

- raft foundation

Can I assume the following:

- you have a +/-20mm positional tolerance in your spec for the position of columns

- the raft foundation has either shear rails or shear links and also has a local thickening at the post position to take the shear around the post

- it is a raft foundation and your post is probably designed as a simply supported post with no moment connection to the raft (unless you have done so specifically)

- your post is designed with probably about 3%-4% steel reinforcement (although it is the lowest post in the structure)

- a 500x500 post makes it sound like a 6 storey building (this is a hazardous guess but given that you have come to this forum, I assume that you are not talking of a very important building)

Advice is:

- it is the contractor's error and in your spec you have clauses that say that the contractor is to propose a solution for the consultant's approval

- the contractor should employ an engineer to show how he is going to rectify things so that they are the same as the architect originally intended

Practically this amounts to:

- reducing the size of the column (by about 50mm on one side out of the 500mm post) and perhaps installing some additional re-bar by drilling in chemically bonded re-bar e.g. resin anchors as deep as the raft allows

- decrease one dimension and increase the other so that it is now 450x550

- increasing the concrete strength for the post concerned from say RC40 to RC50

- getting calculations from the contractor which show that the proposed new set-up works