Any time you exceed a listed gross axle / gross vehicle weight rating you put yourself in a " Unsafe Operation " and will be subject to fine and placed out of service if a Federal Motor Carrier inspection is performed on you.
As far as legal weight that can be carried by your truck and trailer depends on some different factors.
Namely, length and axle spacing.
In Alabama, weights differ between interstate and secondary roads. Alabama allows 10% more weight on secondary roads.
If you do a Google search for federal highway weight limits you should be able to find the chart that breaks down the weights according to length and axle spacing for interstate highways.
That weight will apply on any Federal Interstate in the country.
By looking at the chart, one would assume a 5 axle combination 16 ft long gets 58,000# total gross weight with 20,000# per single axle and 34,000# for tandem axles. I do believe in your case, you have a triaxle trailer which should get 42,000#.
The longer the combo the more weight you get.
So, it looks like as long as you do not exceed any of those numbers you would be good on weight but...........
If you get inspected and exceed any of the manufactures ratings then that would put you in a unsafe operation and you could be fined and placed out of service.
If you load your combo up to the numbers above YOU WILL BE IN A UNSAFE OPERATION !!!!!