Increase capacity of existing foundation 3

[mte12]

Can this be solved practically?

For an existing pad footing buried in the ground, supporting a column, where the load increases from say 1000kN to 2000kN (in compression), how could one or both of these problems be solved.
1. Crushing in base plate. Because base plate is relatively thin, compression load cannot be transferred to grout/concrete.
2. Bearing capacity of foundation.

Criteria is no vertical settlement of column, and load transfer to be guaranteed.

 

[TLHS]

The thing to do is (semi-anxiously) overthink to the point where you're able to confidently say "nobody else in my position would be worrying about this at all" and then try to dial it back 10%. One day I'll figure out the last bit

 

[mte12]

Thanks for additional comments, but again I think intention is not understood.

By no movement of column, this was for the temporary condition during installation.

I don't think it's fair to suggest that expectation was to have zero settlement. But again my fault for not presenting more clearly.

Understand KootK's proposal of preloading, by this I presume jacking upwards, which I have called up in the past but it hasn't been accepted. Perhaps jacking up column may be inevitable.

 

[phamENG]

By no movement of column, this was for the temporary condition during installation.

Oh. Right. Well that certainly changes things. Welding stiffeners onto the column base and expanding the footing by doweling in if it's deep enough to transfer moment. Otherwise, shore the column, weld on a new baseplate, and replace the footing.

 

[Once20036]

I agree with you for steps 2 and 3 pham, but I always start with something else first.
Basically, most of my base plates are over sized in order to get the geometry that I need for the anchor bolts.
For an existing condition like this, I`ll figure out the smallest base plate dimensions required to prevent crushing of the concrete, then figure out that thickness required for that base plate.
If I have that thickness, I`ll call it good.

Basically, if a 12x12x1/2" base plate is sufficient, would an 18x18x1/2 base plate really be a problem? The 18x18 plate would yield in bending, deflect, and the load under the base plate would approach a 12x12.