Enlarging an existing column footing
Enlarging an existing column footing
(OP)
Does anyone know of a calculation procedure for enlarging an existing column footing due to additional loading? At the interface of the new concrete where bars embed in to the existing footing, there should be a calculation to determine the bars size and spacing based on the new loading. I've never encountered this situation.






RE: Enlarging an existing column footing
Dik
RE: Enlarging an existing column footing
It might be better though if you could attach a beam or something to the bottom/edge of the column that would then spread the load into the current footing and new footing from the top. Then you don't necessarily have to connect the footings into one integral unit.
Just an idea. I've never done this, personally.
RE: Enlarging an existing column footing
dik
RE: Enlarging an existing column footing
If the original footing has shear capacity you will likely have to extend dowels far enough into the existing footing to resist the moment.
RE: Enlarging an existing column footing
Just thinking out loud -- never worked on something like that before...
RE: Enlarging an existing column footing
RE: Enlarging an existing column footing
RE: Enlarging an existing column footing
So do what dik and Hokie said instead.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Enlarging an existing column footing
Use TLHS's procedure. I normally add dowels top and bottom for an added comfort level. You will need to widen the footing by at least two feet so they have room to drill the holes for the dowels.