For Undisturbed Sample Area Ratio Should Be?

For obtaining good quality undisturbed samples, the area ratio should be 10 per cent or less.

When the area ratio is 10% or less the soil sample generally is considered to be undisturbed?

Degree of disturbance:

A soil sample generally can be considered undisturbed if the area ratio is less than or equal to 10%. The area ratio for the standard spoon sampler is nearly 110% and for Shelby, tubes are 13.5 %.

What is area ratio for good quality of undisturbed sample what should be its value?

The area ratio should be preferably be less than 10 %, but it is possible that the greater area ratio can be tolerated when the sampler is provided with a stationary piston and / or the cutting edge having very small angle of taper . For good sampling process, the ratio should be within 0-2 %.