Geotechnical engineering is the method of utilizing scientific thinking to design and engineer applications for raw, earthy materials, like soil and rocks. Its main area of focus is ensuring that the earth, overall, is more habitable and suitable for humans. Amongst the many geotechnical engineering principles, soil compaction stands out as one of the major applications of geotechnical science. In simple terms, the process of soil compaction is mainly about mechanically putting enough pressure on soil particles to make them closer and compact enough to be used in numerous activities. The properties of soil particles are altered by soil compaction to suit the engineering needs of a certain project. To make things easier for you, we’ve compiled a guide that contains the basic procedures you should follow for proper soil compaction.
Compaction Forces and Equipment
Soil compaction requires industrial machinery to be done right. The type of machinery may vary according to the soil’s structure as well as the nature of the project. If you glance at any job site in the world where soil compaction is taking place, you’ll find tamping rammers, jacks, vibratory compactors, rollers, and other heavy machinery. There are two distinct types of forces that are used during soil compaction.
- Vibrator: This type of force uses the vibrations from the engine-driven machines to create a downward force that pushes the soil to become more compact, not to mention the static weight of the machines that’s also adding to the downward force.
- Static: There is no work done on the soil to push it downward, except that of the static force produced from the weight of the machines on top of the soil. It utilizes gravity to push the weight of the machine downward to bring soil particles closer.
With vibratory-based machines, the force used in soil compaction is identified accurately according to the frequency and amplitude produced by the machine. Vibrations are measured per minute, and they represent the frequency of the machine as it pumps to produce a downward force. The amplitude of the machine is the maximum distance allowed for it to move away or towards the soil. The higher the amplitude, the more force is created by the vibrations of the machine.
Types of Soil Compaction
The type of compaction used for soil or asphalt varies according to the desired outcome. It’s important to settle on the type of force used, whether it’s vibratory or static, and stick to it. The main types of compaction are classified into 4 categories.
- Pressure: Providing continuous physical downward force on the soil ensures that the buried materials are placing enough force.
- Impact: Force produced through the contact of two different solid objects.
- Kneading: Movement alternated between different locations to produce a high amount of sheer force.
- Vibration: The vibration of the particles as the weight alternates in two opposite directions on the same axis along the center of equilibrium.
Testing Phase
The testing phase is essential to the soil compaction procedure. It involves continuously measuring the density of the soil to monitor the fluctuations as the air is driven out. Testing strips are a basic and a sure-fire way to determine the best method of compaction. Every layer of sound may have different percentages of density on a proctor curve. It is possible to meet some problems when you’re trying to find the right parts for filters and air compressors as this equipment can break down faster under load. Besides testing the soil, the distributors of construction machinery and equipment at Ablesales believe that getting a one-year warranty with a full-time mechanic and workshop is the best way to ensure that your work or project never stops. Since the machinery used in soil compaction is often on the pricey side, investing in high-quality equipment will help you in the long run.
Preparation of Soil
Before you begin the process of soil compaction, it’s imperative to find out whether the soil is actually prepared for undergoing the procedure. The percentage of wetness and dryness of the soil needs to be balanced at 50% for both. There is no need for sophisticated machinery to know whether the soil is overly wet or dry. Simply pick up a good bit of soil with your hands and then squeeze it. If it’s too powdery, that means that the soil isn’t ready for compaction because it’s too dry. The perfect soil for compaction should stay in one piece after you squeeze it and drop it on the ground.
Variables of Soil Compaction
There are a lot of factors that can affect the quality of soil compaction; ignoring them can sometimes ruin the whole project or even create hazards. Here are the most important factors that are taken into consideration before the process of soil compaction takes place.
Water Content
The drier the soil, the more resistant to soil compaction it will be. This is why increasing the water content of the soil is a common measure taken to make the soil more accommodating for the compression process. Optimum moisture content (OMC) is the content of water that balances the maximum dry density of the soil.
Degree of Compaction
Increasing the compaction force will eventually increase the dry density of the soil if it has low water content. The dry density is the pure density of the solid mass in the soil. It’s the main metric that controls the success of the soil compaction process.
Soil Type
Since soil is a mixture of solids, liquids, and gasses, it’s not uncommon to stumble upon different kinds of soil that require tailoring the procedure of soil compaction. To be able to achieve the best dry density of the soil, you’ll need to make sure that you’re using the right method of compaction.
It’s almost impossible to build earth dams, canals, roads, runways, and a plethora of other essential structures without using the geotechnical process of soil compaction. Since every project requires different levels of soil compaction, optimizing the procedure to meet your demands can often be difficult if it’s not approached as a unique problem with its own metrics and properties.
