regarding concrete basement floor and adding wall/supports to reduce sag

Question

I have a basement slab, and a triple 2x10 backbone supported by steel columns. I've got a little sag in one which combined with other issues above, results in less than desired sag in the second floor (maybe a half inch).

Focusing on this part of the puzzle, the beam isn't sagging all that much, but i can see where it's bearing on the steel column it's smushed a bit at the bearing.

the basement is unfinished but would like to slowly finish it here and there, the first part being partition walls. it makes sense to put walls up along the underside of this beam.

Finally, the question: putting up such partition walls under the beam, what do i need to know about jacking the beam to give load to the partition walls to reduce the sag of the main beam? I understand the steel columns are on thick footings, but what's the word on spreading some load on the rest of the floor?

Bonus question: would it make sense to "sister" the steel column, putting a support just next to it so it's still on the footing to effectively add bearing(remember the smush?)

thanks!

Answer 1

I would add a steel plate to the top of the column to spread the load on the 2 X 10 s. Plate about 1/4 " thick or more , This will also compensate for the crush that has already happened. I have been able to find miscellaneous pieces of steel at a local weld shop at reasonable price. There should be some foundation under the concrete floor to support the steel column ; The floor itself can be very thin, I once found a 1 / 4 " thick spot in a basement floor concrete. So you can't just put a new column anywhere.