Frictional Angle (ϕ)˚
Relative Density
SPT-valued (Nspt)
Blow Numer/30 cm
Value
Description
27 - 30
0 - 0.15
very loose
0 - 4
30 - 32
0.15 - 0.35
loose
4 - 10
32 - 36
0.35 - 0.65
medium
10 - 30
36 - 40
0.65 - 0.85
dense
30 - 50
>40
>0.85
very dense
>50