Almost each of the pile was done in deviation from the original design location I'd designed, about 2% to 20%
Do you know a kind of rectification for this kind of installation errors, or just to execute some other ones?
Harold mentioned DFI. I didn't see anyone mention ACI 117, which contains Tolerances for concrete work including bored pile foundations. I think it's pretty complete.
As far as rectifying the problem, here in the states, "the contractor proposes and the engineer (as representative for the owner) disposes." In other words it's not for you to come up with remedial methods, it's for the contractor to propose them and you are responsible for acceptance.
The contractor SHOULD have enough money in the bank to hire his own engineer if he needs help with that, FWIW.