Knowing how to compact the soil is very important in planning and construction. This article provides detailed instructions on how to do this.
Soil compaction is the application of mechanical compaction forces to compact soil. This reduces the volume of the soil and the soil particles are closer together, reducing the proportion of pores. When particles are compressed to reduce the distance between them, compaction occurs.
By reducing the volume of soil, its weight per unit area increases. Furthermore, maximum dry density can be achieved in the compaction process with optimum moisture content.
Soil compaction is most common in the construction industry. This allows us to maintain more stable soils. In the construction of roads, runways, parking lots, skyscrapers, foundations, etc., soil compaction is carried out in accordance with the respective requirements.
Therefore, it is important to know how the soil is compacted to the required level and what procedure is used.
Purpose of soil compaction
The bearing capacity and stiffness of in situ or chemically modified soils can be increased through soil compaction. Compaction tends to increase the shear strength of the soil.
By making the soil stiffer and reducing voids, potential soil settlement can be minimized. Eliminating voids reduces the likelihood of soil settlement, shrinkage or swelling, and water infiltration, all of which can adversely affect the soil's ability to shrink and swell.
Furthermore, parameters associated with soil settlement are also improved to reduce settlement.
On the other hand, if we have loose soil or soil replacement and carry out the work without any compaction, serious problems will arise such as foundation failure, differential settlement, excessive settlement, etc.
Therefore, it is important to know the importance of soil compaction and how soil is compacted.
Factors affecting soil compaction
There can be many factors or variables that affect soil compaction. The most important of them are discussed in the article.
- Soil type
- soil moisture
- Compaction Machine
- Soil layer thickness
- Compression speed
- Number of passes
The effects of soil on the soil compaction method are discussed in the article Factors Affecting Soil Compaction .
Available Soil Compaction Method
There are numerous techniques for compacting the soil. Static forces physically and constantly compact the soil by applying weight pressure. The soil can be manipulated, such as: B. kneading or shearing the soil in alternating directions to compact it more deeply.
A vibrating device can also be used to apply dynamic force in addition to pressure and manipulation. Vibratory compaction techniques apply force in alternating directions using different amplitudes and frequencies, usually through the use of a rotating weight to apply rapid blows to the surface.
Let's discuss different soil compaction methods. The most commonly known methods are:
- Vibratory compaction
This method involves vibrating the soil to obtain the necessary compaction. This method is particularly suitable for soils with low cohesion.
- Dynamic soil compaction
This method is very specific and is not used frequently. Dynamic compaction is only carried out on special occasions and when it is necessary to compact large areas.
To achieve compaction, a weight is placed on the soil. The weight, the distance between each compaction point and the number of blows per point are determined depending on the degree of compaction to be achieved. Compressed soil test data can also be used to finalize requirements.
The article on Soil Improvement Methods For more information, see this page.
- Conventionally used mechanical compaction methods
Compaction classification is based on the compaction machine used. Depending on the type of structure and the degree of compaction, the expected compaction method can be determined.
Some of the machines used for compaction are as follows.
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- Light compaction equipment (compactors/plate compactors)
- Smooth Wheel Rollers
- Sheep's foot rolls
- Rubber Wheel Rollers
- Vibratory rollers
- grid rollers
How to Test Soil Compaction
Knowing how to test compaction is as important as knowing how to compact the soil.
The degree of compaction can be assessed using various compaction test methods. To understand the initial conditions at the project site, preliminary on-site testing is necessary.
The following test can be used to check soil compaction.
- Proctor Compression Test
- Nuclear test
- Sand Cone Test
- Balloon Density Test
According to your needs, the testing method can be selected. Proctor compaction tests and sand cone tests are common in road construction work.
The degree of compaction is measured during construction. We can determine the maximum soil density for ideal moisture content. This is compared with the density of the soil obtained in the field.
It is usually maintained at 95%. If we build on soil with 95% compaction, we assume we have a good platform. This does not mean that the underlying layer has no influence on the settlement of the foundation. It must also be in good condition to support compacted fill.
