Hi,
There are some equations that have the relationship between SPT-N values and settlement.
(Meyerhof)
Se=4*q/N for B<=4 ft
Se=6*q/N*((B/(B+1))^2 for B>4 ft
q: intensity of applied load, kip/ft^2
B: width of footing, ft
Se: settlement, in
(Bowles)
Se=2.5*q/N for B<=4 ft
Se=4*q/N*((B/(B+1))^2...