The two types of soil samples collected for further study are;

• Disturbed sample
• Undisturbed sample

Disturbed Soil Sample

As the name implies; the sample is disturbed by the method used in collecting it. Soil samples collected using the auger, percussion or rotary drill, shell or by hand can result in samples in which their natural structure has been substantially interfered with. Such samples are therefore generally useful for determining moisture content and visual grading.

Undisturbed Soil Sample

These are samples removed by methods which preserve as far as possible the natural structure and properties of the soil material. Methods of collecting undisturbed samples include, by hand, core drilling.

Of the two types of soil samples discussed so far, the undisturbed soil sample gives the best test results.