There is a unique relationship, independent of time, between the void ratio and effective stress.

The shear strength of soil depends on many factors including the effective stress and the void ratio.

Void ratio is mathematically related to the porosity.

Depending on the initial void ratio, the soil material can respond to loading either strain-softening or strain-hardening.

The void ratio is the void area of the tire divided by the entire tread area.

The pre-consolidation pressure evolves as the void ratio () (and therefore the specific volume ) of the soil changes.

The rate of contraction is high if the confining pressure is large and the void ratio is large.

The tendency for a soil to dilate or contract depends primarily on the confining pressure and the void ratio of the soil.

The data is usually arranged on a semilog plot of the effective stress (frequently represented as σ') verses the void ratio.

If void ratio is high (loose soils) voids in a soil skeleton tend to minimize under loading - adjacent particles contract.

Contractive soils become denser as they shear, and their rate of contraction decreases until they reach a critical void ratio.

This is due to the non-linearity of the relationship between void ratio and effective stress, although for small stress increments assumption 7 is reasonable.

Mud and snow (M&S) tires are designed with higher void ratios to channel away rain and mud, while providing better gripping performance.

Void ratio, , is the ratio of the volume of voids to the volume of solids:

Using a load increment ratio of 1/2 provides a sufficient number of data points to describe the relationship between void ratio and effective stress for a soil.

Laboratory data is used to construct a plot of strain or void ratio versus effective stress where the effective stress axis is on a logarithmic scale.

The opposite situation, i.e. when void ratio is relatively small (dense soils), indicates that the volume of the soil is vulnerable to increase under loading - particles dilate.

Extend the "straight portion" of the recompression curve (high effective stress, low void ratio: almost vertical on the right of the graph) up to the bisector line in part 4.

High performance tires have small void ratios to provide more rubber in contact with the road for higher traction, but may be compounded with softer rubber that provides better traction, but wears quickly.