Penetration Tests and Soil Sample Exploration – MCQ
1. The SPT-N value is the number of blows required to drive the sampler through the last
a) 15 cm
b) 30 cm ✅
c) 45 cm
d) 50 cm
2. The type of sampler used in standard penetration test is
a) Shelby tube sampler
b) Piston Sampler
c) Split Spoon Sampler ✅
d) Any of these
3. The first 15 cm of drive is considered
a) Blows for SPT
b) Blows for SPT-N
c) Blows for seating drive ✅
d) None of these
4. The hammer falling height is considered as
a) 75 cm ✅
b) 80 cm
c) 85 cm
d) 90 cm
5. The no.of blows for SPT will be
a) For the first 150 mm penetration
b) For the next 300 mm penetration ✅
c) Addition of (a) and (b)
d) None of these
6. After correction standard penetration value is equal to
a) 10 + 0.5(N-15)
b) 15 + 0.5(N-15) ✅
c) 20 + 0.5(N-15)
d) 30 + 0.5(N-15)
7. N value for loos sand is
a) 4
b) 8
c)10 ✅
d) 12
8. N value for very loos sand is
a) 2
b) 4 ✅
c) 8
d) 10
9. Chunk sampling is the process of
a) Disturbed sampling
b) Undisturbed sampling ✅
c) Both (a) and (b)
d) Water sampling
10. A good quality undisturbed soil sample is one which is obtained using a sampling tube having an area of
a) 24 %
b) 16 %
c) 12 %
d) 8 % ✅
11. Undisturbed soil samples are best collected by
a) Thin walled samplers ✅
b) Thick walled samplers
c) Direct excavation
d) Auger
12. The dilatancy correction in SPT is given by
a) N’ = 15 + (N-15)
b) N’ = 15 + 0.5(N-15) ✅
c) N’ = 15 + 0.5(N-10)
d) N’ = 15 + (N-10)
13. The degree of disturbance of soil sample is generally expressed by
a) Void ratio
b) Recovery ratio
c) Area ratio ✅
d) Consolidation ratio
14. The area ratio for a sampling tube with an inner diameter of 72 mm and outer diameter is
a) 0.85
b) 0.085
c) 8.5 ✅
d) 0.065
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