5 Soil Testing Types Before Any Construction Project

Before a construction project begins, the ground is tested to ensure it can bear the weight of the buildings.

There are several different soil testing techniques available. The one you use depends on the project requirement and soil characteristics. 

We’ll look at various soil testing procedures used for construction projects.

Moisture Content Test

This test determines the ratio of water in the soil. It calculates whether the soil type is appropriate for construction. The results can also help detect contamination and suggest remedial measures to eliminate it.

The soil’s moisture content is evaluated using several methods, including oven drying, boiling, wet combing, filtration, and others. The test results include a percentage of water present in the soil. 

Oven drying is a procedure in which soil samples are dried in an oven at 100°C for 24 hours, the amount of water released during the process is then calculated. Soar specializes in such geological consulting services. 

Specific Gravity Test

The particular gravity of any material is determined through the ratio of the density of water to the density of a material. This is calculated using a variety of different methods. Some examples can be the gas method of jars, the measurement flask method, and the density bottle method.

Atterberg Limits Test

This test estimates the required water content of fine-grained soil. Three limits can calculate the characteristics of a fine-grained soil:

  1. Limit of Shrinkage: A mathematical formula specifies the water content that fills the soil void. 
  2. Limit of Plastic: A soil sample is mixed into water to make it plastic. It is then molded into a ball shape and formed into 3mm threads. If the threads don’t break, the process repeats with smaller amounts of water and a fresh soil sample. The process continues until the thread breaks.
  3. Limiting Liquids: A Casagrande’s liquid limit device determines the moisture content at which clay soils pass from plastic to a liquid state. 

Dry Density Test

The soil density is determined using the weight of soil particles present in a given sample. The dry density is determined by the specific gravity of the soil and the void ratio. 

It is used to classify the soil into various densities: loose, medium dense, or highly dense. This test may use three other methods – core cutter, water removal from the core, or replacing sand.

Proctor’s Compaction Test

The test determines the compaction characteristics of the soil. This soil specimen dries by air and is split into four or six smaller pieces. 

The water content of the samples is modified by adding three to five percent water. The samples are placed into the Proctor compaction molds in three layers. Each layer receives 25 blows with the standard 5.5-pound hammer. 

The samples are removed and dried, then their dry density and water content are measured. The curve is constructed based on a set of results – including the density of the water content. This curve will represent the ideal water content required to achieve the highest dry density.

Final Word

Selecting a reputable environmental firm specializing in soil testing, groundwater investigation, assessment, and remediation is essential.

Any questions? Ask us in the comments!