5.4 - Compaction and consolidation

Question 1

Compression

Answer 1

The application of a load to a soil

Question 2

Compressibility

Answer 2

a property of a soil relating to its susceptibility to decrease in volume.

Question 3

Compaction

Answer 3

The densification of a soil by means of mechanical manipulation or, more specifically, the expulsion of pore air by mechanical means

Question 4

Consolidation

Answer 4

The process of squeezing water out of saturated soil under the effect of loads (compression)

Question 5

Settlement

Answer 5

The gradual downward movement of an engineering structure caused by compression of the soil below the foundation.

Question 6

What types of methods are used to achieve ideal conditions (i.e., types of soil, types of technique, factors impacting consolidation)

Question 7

Explain Terzaghi’s principle using spring analogy

Answer 7

The stiffer the spring the less it will compress. Therefore a stiff soil will undergo less compression than a soft soil.

Question 8

Normally consolidated vs over consolidated sediments

Answer 8

Normally consolidated soils:
present effective stress = preconsolidation pressure
Over consolidated soils:
present effective stress < preconsolidation pressure

Question 9

Major types of field compaction

Answer 9

Static - All types of soils
Kneading - Fine grained soils
Vibratory - Granular soils
Dynamic - Loose deposits of sand and silt