Effects of Soil Compaction

When soil is compacted, the density increases. Picture a bucket full of loose soil, its heavy but can be lifted easily. Now picture that same bucket of soil, but now you've stepped on the soil to compact it and more soil has to be added to fill the bucket to the top. The bucket with compacted soil is heavier and can't be lifted quite as easily.

The compacted soil takes up the same amount of physical space as the loose soil; however, its weight is much heavier. This means the compacted soil has a higher density than the loose soil.

Soil is compacted in order to increase its suitability to support a structure such as a building or road. The three most important effects achieved by compaction are that the soil can withstand larger shear forces, settlement (or building creep) is significantly decreased, and the soil is less susceptible to water saturation.

In general, the higher the level of compaction that can be achieved, the greater the benefits experienced by the three effects we just mentioned.

POINTS TO REMEMBER:

• compaction increases density and produces three important effects:
• - an increase in the soil's shear strength
• - a decrease in future settlement of the soil
• - a decrease in permeability
• these three effects are beneficial for various types of construction, such as highways, airfields, etc.
• general rule of thumb - the greater the compaction, the greater the benefits