Question

Consider the following statements related to the properties of a good quality soil sample:
1. Area ratio should be low
2. Cutting edge should be thick
3. Inside clearance should be low
4. Outside clearance should be low
Which of the above statements are correct?

• A. 1 and 2
• B. 2 and 3
• C. 3 and 4
• D. 1 and 4

Answer 1

The correct option is D 1 and 4

For a good quality soil sample (undisturbed sample), the sampler should have low value of area ratio (less than 10% or so). In order to keep $A_r$ less, thin cutting edge is therefore preferred in a soil sampler.
Inside clearance is meant to reduce the friction between the soil sample and the sampler when the soil enters the tube, by allowing for the elastic expansion of the soil. Thus if inside clearance is high, there will be too much of lateral expansion. IS recommends that the outside clearance should not be much greater than the inside clearance.