Net allowable column load calculated by the Terzaghi’s bearing capacity equation
(Part c) is significantly higher than that calculated by the method based on N60 and
limting settlement value (Part b). In actual design of foundations, both bearing
capacity (based on shear strength) and settlement criteria need to be satisfied. It is
possible that the allowable column load calculated in Part (c) will change
(decrease) if a settlement limit is imposed. Considering the uncertainty in
sampling and testing of granular materials for the determination of shear strength,
the method based on N60 and settlement criteria may be preferable for these