Adding Load to Existing footing
Adding Load to Existing footing
(OP)
Help.
I have some experience with under pinning footings but not with adding 100 kips to an existing footing. See attached PDF. They want to add a crane column to an existing footing. Can I just dowel into the existing footing and add footing size and check the dowels for shear and bending? Or do I need to underpin?
It is complicated.
I have some experience with under pinning footings but not with adding 100 kips to an existing footing. See attached PDF. They want to add a crane column to an existing footing. Can I just dowel into the existing footing and add footing size and check the dowels for shear and bending? Or do I need to underpin?
It is complicated.






RE: Adding Load to Existing footing
RE: Adding Load to Existing footing
Your section shows a footing that is 2'-10" thick (3'-6" - 8") are you sure it's that thick? I usually shy away from "adding to the footing size" because it's hard to increase the punching shear or fluexural capacity of an existing footing. Not to mention in your scenario you might need top reinforcing in the footing.
RE: Adding Load to Existing footing
RE: Adding Load to Existing footing
RE: Adding Load to Existing footing
2) I don't see how underpinning would help you here unless:
2a) There's a kick as bearing stratum not too far below the existing footing or;
2b) Pouring an entirely new footing under the existing one would somehow be more cost effective.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Adding Load to Existing footing
RE: Adding Load to Existing footing
Do you mean footing under existing?
BA
RE: Adding Load to Existing footing