Why is Soil Testing so Important in Construction?

Why is Soil Testing so Important in Construction?

It can be a dreadful experience if your newly constructed residential apartment project slowly starts sinking on one side or worse develops cracks with all the possibility of the building collapsing in due course of time. All your effort, time and money go in vain. 

The thumb rule here to avoid such a situation is to ensure that proper Soil Tests are conducted on the desired plot before you start the construction work.

What is Soil Testing?

Ideally, Soil Testing must be performed for all types of construction as it helps understand the suitability of the soil for  proposed construction work.It is a process carried out to assess different physical and engineering properties of soil including 

  • Water Content 
  • Moisture Content
  • Presence of Mineral
  • Bearing capacity
  • Density
  • Permeability

This information is also the primary factor in deciding the type of foundation and  quality of material to be used for construction. For example, once you find high sulphur content in the soil, use sulphur resistant cement for construction.

Soil Testing and Load Bearing Capacity

Primarily, soil testing is performed to test the bearing capacity of the soil. So, what exactly is this bearing capacity of soil?

“The maximum load per unit area which the soil  can carry without yielding or displacement is termed as the bearing capacity of soils.”

Other properties of soil that affect the bearing capacity of soil include permeability,  shear strength, and density.

What is the Importance of Soil Bearing Capacity in Foundations?

As we all know the foundation is the most important component of any structure. As the entire load of the structure is transmitted to the foundation.Further, the foundation transmits the load to the soil beneath it.The intensity of load per unit area is determined by  the area of soil at the base of the foundation.

Planning to design your foundation? Care must be taken that the total load of the structure is less than the bearing capacity of the soil. This is important as the soil failing to withstand the weight of the structure can lead to loss of life and property.

Relevance of Soil Testing 

The soil analysis also helps determine:

  • Rate of settlement of the soil
  • Physical, mineral and chemical composition 
  • The appropriate construction technique
  • If any additional testing is required for building the infrastructure
  • The length and depth of the pillars needed to lay the foundation of the building in the soil
  • Potential problems that may occur in the foundation 

What are the Types of Soil Testing in Building Construction?

In general, the following tests help to determine the quality of soil:

Moisture Content Test 

This test provides all the relevant information about the moisture or water content in the soil. This helps in understanding the  impact of humidity on the foundation.

Specific Gravity Test on Soil 

By measuring the specific gravity of the soil (i.e. the unit weight of soil solids to that of the water), the test provides information about void ratio and degree of saturation in soil. 

Ideally, the specific gravity value should range from 2.65 to 2.85. Values above 3 indicate the presence of heavy substances in the soil whereas a value less than 2 indicates the presence of organic and porous matter. 

The soil used for construction should contain low amounts of porous matter, organic content and heavy materials.

Atterberg Limits Test

Helps measure the critical water content of the soil at different conditions like liquid limit, plastic limit and shrinkage limit.

Dry Density Test on Soil 

Dry Density of soil is the weight of soil particles in a given volume of sample. The soil is classified into dense, medium dense and loose based on the values of dry density soil.

Compaction Test

The test reveals the compaction characteristics of the soil. In case you are wondering what is Compaction ? It is a process of reducing air voids in the soil by densification. The outcome of the test determines the optimum water content and maximum dry density of the soil.


It is evident that soil testing in building construction is a time-consuming process. But not doing proper tests can result in building failure and safety of your structure is way more important than the time, money and effort you spend on soil testing.

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