Why would you want to deliberately over load a trailer? Most have a maximum weight rating. You can legally permit a 5 axle truck and trailer for 92,000 pounds in most states, as I recall. That is 2 axles on the trailer and 3 on the tractor.
Just ask the guy I spoke to around 15 tears ago whose friends truck broke down, at the shipper so he told them to put his load (also) on his trailer. He was caught on an scale in ca. grossed out at 160,000 lbs. thrown in jail and fined $150,000. He spent ten years paying the ticket off, and he had the newspaper article and a copy of the ticket to prove it. I also believe the story was it the truckers paper, and I thought I had a story to tell about blowing thru the mojave at 122 mph leaving barstow with a load of produce,at 3am., and he said; you ain't gonna believe this ----.
I never want to over load my equipment. My trailer is rated for up to 100,000 pounds, but there is NO way that I would attempt to put that much weight on my trailer. There are some steel haulers who used to take 2 loads at the same time so that they can get twice the pay rate. Not only is it dangerous, it could cost you dearly should you become involved in an accident. I don't over load my equipment. If I can't make money on something without having to over load my equipment, I figure it is too cheap and that I don't need to haul it.