Regardless if the bend was "natural" due to inadequate frame, or something/someone participated in it, I think what matter at this time is how to fix it.
I am a welder when I need it and as I mentioned- probably the best fix is add welded plate on the side of I-beam.
Question is how to get the beam straight, or preferable bend other way for the time of the welding?
Will the center of the beam sag, when you jack up the ends?
In the past I was using 2x8 C-channels as ramps for equipment loading.
But one of those 10,000lb backhoes bend the chanel.
My reinforcement was adding welded rebar on the tips of C. But I did not have 10k press to straight it before reinforcement.
What I did was weld one end of the bar to the channel, than with torch warm up the bar in the range of 600F and then quickly weld the other end of the bar to the chanel.
Than I did 3" welds every foot.
Rebar when cooling down, shrank and pulled the chanel straight.
Obviously having trailer on the top of the chanel makes using torch a danger job, but similar effects can be done with cooling.
