Compaction of Soil

Compaction is defined as ______________________

• the mechanical process to increase soil density, to increase void and reduce permeability

• the mechanical process to increase soil density, to reduce void and reduce permeability

• the mechanical process to decrease soil density, to reduce void and reduce permeability

• the mechanical process to decrease soil density, to increase void and reduce permeability

Select ALL of the objectives of compaction.

• To reduce the void ratio

• To increase the shear strength

• To decrease the bearing capacity

• To avoid future settlement

Factor controlling the effectiveness of the compaction

• The type of soil

• The water content

• The maximum amount of compaction

• The type of compaction effort being used

Which soil can be compacted to higher density?

• Poorly graded sand

• Well graded very gravelly SAND

• Uniform silty soil

• Clay of high plasticity

What are the parameters to determine the characteristic of soil compaction

• Maximum bulk density

• Minimum moisture content

• Maximum dry density

• Optimum water content

What are the effects of water content in the compaction of soil?

• As moisture content increase, the air void content decreases, and the soil approaches the Av=0

• Adding water at low moisture contents makes it easier for particles to move during compaction and attain a lower void ratio.

• The soil reaches a maximum dry density at the lower moisture content

• The soil reaches a maximum dry density at optimum moisture content.

Calculate the dry density of the soil, if the bulk density is 2.0 Mg/m3 and Water content is 20%.

• 0.09 Mg/m3

• 2.4 Mg/m3

• 0.6 Mg.m3

• 1.67 Mg/m3

Determine the moisture content of the soil. Given the mass of the wet soil = 450 g, the mass of dry soil = 353 g.

• 78 %

• 22 %

• 27 %

• 12%

Which method is suitable to obtain the field density for silt & clay

• Sand replacement method

• Core cutter method

• Field compaction using grid roller

• Field compaction using the smooth wheeled roller

The maximum dry density achieved from the laboratory is 1.87 Mg/m3. The dry density obtained from the field test is 1.75 Mg/m3. Determine the relative compaction (%) of the soil.