Correcting the Blow Counts

[kxa]

Do we always need to correct the blow counts (N) for overburden pressure before determining the bearing capacity and settlement? I have seen clac's done both ways. I am designing shallow foundations (spread and wall footings)slightly above groundwater table and in some locations 1' below water table. Have a 3' min. frost depth.
Thanks

 

[Mccoy]

It depends, the recent formulas for the friction angle usually carry the correction. The old formulas do not, whereas the formulas for the moduli usually do not carry overburden corrections.
I use some older formulas without corrections because they have some desirable properties or give better results for certain soils.