What Is Compaction of soil?
It is a ground improvement technique in which soil is densified through the external effort.
As we all know that a soil in loose form has air entrapped between its particles when we do the compaction by external effort we are actually reducing the air voids in the soil by reducing the air voids some changes occur in soil which are really good for our project construction.
Why we do compaction?
Compaction measurement:
Compaction is measured in terms of dry density. Dry density is weight of soil solid per unit of total volume of the soil mass
Test use for compaction measurement:
It is a ground improvement technique in which soil is densified through the external effort.
As we all know that a soil in loose form has air entrapped between its particles when we do the compaction by external effort we are actually reducing the air voids in the soil by reducing the air voids some changes occur in soil which are really good for our project construction.
Factors affecting degree of compaction:
- Soil type
- Compaction effort
- Moisture content
- Layer thickness
- Speed of roller
- No of roller passes
- Contact pressure
Effect of Moisture Content, Soil type and Compaction effort on compaction of soil:
Compaction equipments:
- At low water content, the soil is stiff and offers more resistance to compaction. As the water content is increased, the soil particles get lubricated The water act as a lubricant. The soil mass becomes more workable and the particles have closer packing.The dry density of the soil increases with an increase in the water content till the optimum water content in reached. At that stage, the air voids attain approximately a constant volume. With further increase in water content, the air voids do not decrease, but the total voids (air plus water) increase and the dry density decreases it is because the water takes the place of soil particles.
- The compaction of soil depends upon the type of soil.For example Cohesive soils have high air voids. These soils attain a relatively lower maximum dry density as compared with the cohesionless soils. Because Such soils require more water than cohesionless soils and therefore the optimum water content is high. Heavy clays of very high plasticity have very low dry density and a very high optimum water content.
- The compaction of soil increases with the increase in amount of compaction effort. With increase in compactive effort, the optimum water content required for compaction also decreases. At a water content less than the optimum, the effect of increased compaction is more predominant.
The following equipments are mainly used for compaction of soil:
- Smooth Wheeled Rollers:
- Sheepsfoot Rollers: Sheepsfoot rollers also known as a tamping roller. ...
- Pneumatic Roller:
- Vibratory Roller:
- Rammers: ...
- Vibratory Plate Compactor
Why we do compaction?
we do compaction because by doing compaction we achive the following 3 physical advantanges:
- Soil get strength
Bearing capacity Of soil increases
Due to compacting Slope stability increases
- volume changes decreases
settlement decreases by compacting the soil
swell potentianl decreases by compacting the soli
- Hydraulic conductivity decreases
Compaction is measured in terms of dry density. Dry density is weight of soil solid per unit of total volume of the soil mass
- Standard proctor test
Procedure of Standard proctor test
- Modified proctor test
Comments
Post a Comment