The Purpose of Compaction of Soil Testing

Posted by TERRATEST GmbH on August 8th, 2017

The process of soil compaction at all sites is driven mainly by the need to offer more stability to the structure.  Other factors contribute to soil compaction, such as improvement in load bearing capacity, reduction in seepage and settling of soil. Soil compaction is mandatory at most sites where the soil is not of the required density or loosely compacted. Here is a deep look at the purpose of soil compacting testing. 

#1 - The underlying principle of compacting soil is to reduce the consequent settlement under working loads. During construction important engineering features of soil such as the sheer strength, compressibility and permeability have to be taken into consideration. Soil compaction is intended to increase the shear strength and to decrease the compressibility and permeability. 

#2 - Additionally, compaction reduces the soil void ratio thus making it more difficult for water to flow through soil. This is an important feature of the soil, as it is being used to retain water and it is most appropriate for constructing earth dams. 

#3 - Soil compaction can prevent the building up of massive water pressure, that leads the soil to give way during earthquakes. Soil compaction can be acknowledged as the formula for mechanically increasing the soil density. Poor compaction of soil can lead to undesirable results in future. 

# 4 - Soil compaction is an important aspect of construction activity. Compacted soil provides greater support for structural entities such as foundations of the buildings, roadways and other earth retaining structures. Soil compaction helps to safeguard the construction structure against deterioration during different conditions. 

# 5 - The compaction process not only increases the soil density but also brings about subtle changes in the soil structure. On a comparative scale, the compacted soil has smaller pores than soil that is not compacted. This is the reason why soil compacting is a mandatory procedure followed at every construction site. 

Soil density testing

Soil density testing helps to determine if the compaction will result in meeting the specifications as necessary for the construction. This test also helps engineers to ascertain the effect of moisture on the density of the soil. This also helps in identifying the optimum moisture of the soil, which will help during further stages of the construction. 

Different compaction methods for different soil types

The conditions prevailing at the site, the nature of the soil and the activity determine the type of compaction methods necessary to achieve the ideal compaction specifications. With the different classification of soils such as granular and cohesive, it becomes necessary to choose equipment that is more suited for the task. Wherever the soil involves a combination of different types, the preferred option is to factor in the larger percentage of the soil type in the combination. Different machines are used to compact different types of soil, such as rammers, vibratory plates, reverse vibratory plates, rollers, walk behind etc. With the right equipment and processes, it is possible to compact the soil to the desired specifications to improve structural reliability. 

About the Author

TERRATEST GmbH is a German manufacturer of light weight deflectometers for dynamic load bearing capacity test. This test is done to evaluate the compaction in road constructions, track laying, earthworks, infrastructure works, etc.