Soils at points N1 and R2 have the same current stress, and so would be at the
same depth in the ground, but they have very different stiffnesses related to λ and κ
respectively. Similarly, soils at points R2 and N2 have nearly the same specific volume
and water content but, again, they have very different stiffnesses. Soils at pointsN1 and
N2 are both normally consolidated; they will have different stiffnesses for loading and
for unloading. This means that soil stiffness is not directly related either to the water
content or to the current stress (or depth in the ground) and the overconsolidation
ratio is an important factor in determining soil behaviour.