What Does Undisturbed Sample Mean?
An undisturbed sample is a soil sample taken intact from below the ground surface, using methods such as cable percussion boring. An undisturbed sample is retrieved with minimal disturbance to its structure, water content, stress state and density. This helps in study and analysis of the soil’s behavior as it exists below the surface.
An undisturbed sample is also known as an undisturbed soil sample.
Trenchlesspedia Explains Undisturbed Sample
Undisturbed soil samples are retrieved with the least possible disturbance to the natural structure. The water content, void ratio and soil structure are preserved to determine soil properties such as:
Drill rigs are used to collect undisturbed samples with tools such as split-spoon samplers and piston samplers. Since it is impossible to obtain completely undisturbed samples, great care is taken while removing, handling and transporting the sample, including protection against change in moisture content. Samples from cohesionless soil are kept in a container, avoiding impacts, jarring or vibration until ready for testing.