Walls and Ceilings - Partition Wall under I-Beam

I'm in process of finishing my basement - in doing so, I'm building a partition wall directly under a steel load-bearing I-Beam that's 6" in width (Basement floor is concrete). In all other areas of the basement I can nail the top plate of all partition walls into the above floor joists, but in this case the whole wall is under the I-Beam and I'm not sure how to best secure the top plate to the I-Beam. Suggestions on how to best do this without compromising the structural integrity of the I-Beam (and passing code)?

Thanks!

If the surface of the beam is flush with the ceiling joists and the sheet rock is not a problem, you could cut a plywood sheet to span the adjacent joists and nail into that.

Alternatively, you could screw into the beam through the top plate with self-tapping metal screws.

Glue your top plate to the steel beam with PL400. Use treated material for your bottom plate, and stick frame your vertical members one at a time to a snug fit. After a couple days, that wall isn't going anywhere. Requires two people to get the job done right.

I recently framed a wall under an I beam. I drilled holes through my header & the I beam and secured the header to the I beam using bolts. Very solid. Plus the added reinforcement by your snug fitting studs makes worrying about compromising the structural integrity a non issue. It's actuall pretty easy to drill through the I beam as long as you have sharp drillbits & a little cutting fluid makes short work of it.