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?)