Relationship between Porosity and Density of Soil

After reading this article you will learn about the relationship between porosity and density of soil.

% soil space = bulk density/particle density

Since, % pore space + % soil space = 100

or % pore space 100 – % solid space

or

% pore space = 100 – bulk density/particle density × 100

% pore space = 100 (1 – bulk density/particle density)

For example, a soil having bulk density of 1.5 and particle density of 2.65. Calculate the porosity of the soil.

% pore space = 100 (1-1.5/2.65)

= 43.40

Therefore, porosity of the soil is 43.40%.

Problem:

A soil core was taken for the determination of bulk density. The measurements were:

Cylinder volume — 73.6 c.c.

Dry soil weight — 87.8 gm.

Particle density — 2.65 gm./c.c.

Calculate the percentage pore space of the soil.

Solution: