Geotechnical Engineering I Mcqs

Q:

The equation for the unconsolidated un drainage strength of clay is __________

A) τ = c + σ tan φ B) τf = ccu + σ tan φcu
C) τ = c + σ D) τ = σ tan φ
 
Answer & Explanation Answer: B) τf = ccu + σ tan φcu

Explanation: The equation for consolidated undrained strength of the preconsolidated clay in terms of total stress can be approximately expressed as τf = ccu + σ tan φcu where, σ is the normal pressure.

View Answer Discuss

11
Q:

If the pore pressure is measured during un-drained stage of the test, the result can be expressed in terms of __________

A) C’ and φ B) cu
C) None of the mentioned D) All of the mentioned
 
Answer & Explanation Answer: A) C’ and φ

Explanation: Both effective parameters C’ and φ’ can be expressed when pore pressure is measured during un-drained stage of the test.

View Answer Discuss

12
Q:

Negative pore pressure in clay or sand is developed due to __________

A) Expansion on loading B) Over loading
C) Loose structure D) Compaction
 
Answer & Explanation Answer: A) Expansion on loading

Explanation: A negative pore pressure is developed when we apply load on a sample of clay or sand because both sand and clay tends to expand on loading.

View Answer Discuss

12
Q:

The value of pore pressure parameter, at failure for saturated clay is __________

A) 1.2 to 2.5 B) 2 to 3
C) 0.3 to 0.7 D) 0.7 to 1.3
 
Answer & Explanation Answer: B) 2 to 3

Explanation: The approximate value of pore pressure parameter at failure for very loose, fine saturated sand, saturated clays is 2 to 3.

View Answer Discuss

13
Q:

Factor affecting pore pressure parameters is ___________

A) Type of shear B) Temperature
C) Nature of the fluid D) All of the mentioned
 
Answer & Explanation Answer: D) All of the mentioned

Explanation: Type of shear, sample disturbance, and environment during shear such as temperature and nature of the fluid are the factors that affect pore pressure parameter.

View Answer Discuss

7
Q:

The change in the pore pressure during an un-drained shear can be explained by ___________

A) Lateral pressure B) Effective stress
C) Pore pressure parameter D) Mohr’s circle
 
Answer & Explanation Answer: C) Pore pressure parameter

Explanation: The change in the pore pressure due to change in the applied stress, during an un-drained, any be explained in terms of empirical coefficients called pore pressure parameters.

View Answer Discuss

9
Q:

Which of the following cannot be obtained by using un-drained test?

A) Effective stress failure envelope B) Shear strength
C) sensitivity D) All of the mentioned
 
Answer & Explanation Answer: A) Effective stress failure envelope

Explanation: Since only one Mohr circle in terms of effective stresses, is obtained from all un-drained tests, effective stress failure envelope cannot be obtained from this test.

View Answer Discuss

11
Q:

The consolidated-un drained test can be performed in ___________ methods.

A) 3 B) 2
C) 4 D) 1
 
Answer & Explanation Answer: B) 2

Explanation: The consolidated-undrained tests are performed by two methods: i) the remoulded specimens are sheared under a cell pressure. ii) the moulded specimens are consolidated under the same cell pressure and sheared with different cell pressure.

View Answer Discuss

7