Question

1) A Standard Penetration Test (SPT was performed at a depth of 10 ft in sand of unit weight 125 lb/ft³. The N-value was found to be 30. Determine the corrected N-value.

C_N = 0.77 x log₁₀ (20/p_o)

• A. 32
• B. 34
• C. 37
• D. 40

2) A standard penetration test was conducted in the field. The boring logger recorded following three readings for 6 inch interval of penetration: 1/2/3. What is N-value?

• A. 3
• B. 5
• C. 2
• D. 6

3) Which of the following tests cannot be performed on disturbed clay samples retrieved from a site?

• A. Water content
• B. Soil classification
• C. Falling head permeability
• D. Standard Proctor compaction

4) Which of the following test requires undisturbed soil sample?

• A. Sieve analysis
• B. Atterberg limit test
• C. Consolidation test
• D. Moisture content

5) Following is not commonly used type of boring for soil exploration?

• A. Auger boring
• B. Wash boring
• C. Rock coring
• D. Rotary drilling

6) What is the benefit of using hollow-stem auger?

• A. Disturbance of soil below borehole is slight
• B. Sampler can be inserted
• C. Can be used in most type of soils and even in rocks
• D. None of the above

Answer 1

1(c) using basic formula of SPTN you can get the answer

2(a) because during test, the number of blows required for starting two 6 inch penetration is neglected because these are provided for seating drive of split spoon sampler

3(a) if the sample get disturbed then water content of sample will get changed.

4(d) as due disturbance water content will change

5(c) rock coring is not soil exploration technique. It's related to rock mechanics or rock exploration

6(a) due to less friction, the disturbance would be very less