Geotechnical Engineering Questions and Answers – Collapsible Soils

Geotechnical Engineering Objective Questions

This set of Geotechnical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Collapsible soils”.

1. Which of the following is exhibited by collapsible soil?

A) Silts where cementing agent is soluble
B) Loose bulky grains hold together by capillary stresses
C) All of the mentioned
D) None of the mentioned

Answer is B)
Explanation: A common feature of collapsible soil is the loose bulky grain held together by capillary stresses.

2. The researchers who have provided guidance for identifying the potential, foot clayey sand and sand clay found in western US is __________

A) Macveren
B) Holtz and Gibbs
C) All of the mentioned
D) None of the mentioned

Answer is B)
Explanation: In 1967, Holtz and Gibbs provide guidance for identifying the potential collapsible soil in arid and semi-arid regions.

3. If the collapsible potential values of the soil are 0-1 %.what will be the severity of the problem?

A) Severe problem
B) Moderate problem
C) No problem
D) None of the mentioned

Answer is C)
Explanation: The severity of the problem will be zero, if the CP value lies between 0-1 percent.

4. Collapsible soils undergoes large decrease in volume due to __________

A) Decrease in moisture content
B) Increase in moisture content
C) Increase in solubility
D) None of the mentioned

Answer is B)
Explanation: Collapsible soils undergo large increase in volume due to an increase in moisture content, even without increasing in external loads.

5. collapsible soils are usually present in areas of __________

A) Semi-arid regions and Arid regions
B) Dry regions
C) All of the mentioned
D) None of the mentioned

Answer is A)
Explanation: Since collapsible soil exhibit loose, weakly cemented sands they are usually present in arid and semi- arid regions.

6. The loose bulky grains in collapsible soil are held together by__________

A) Inter-molecular force between the soil
B) Compressive stress
C) Capillary stress
D) All of the mentioned

Answer is C)
Explanation: As the common Feature exhibited by collapsible soil is capillary stress, the loose bulky grains in the soil are held together by it.

7. The capillary potential (CP) of the collapsible soil varies with _________

A) Degree of saturation and Pressure
B) Water content present
C) All of the mentioned
D) None of the mentioned

Answer is A)
Explanation: The bulk of structural collapse occurs upon the first saturation, at a given over-burden pressure. Hence collapsible potential varies with degree of saturation and pressure.

8. At a given overburden pressure (Po) for a collapsible soil, its collapsible potential depends on _________

A) Degree of saturation
B) Temperature coefficient
C) Moisture content
D) Pressure

Answer is B)
Explanation: In this cement the heat of hydration is reduced by tri calcium aluminate content. It contains less percentage of lime than ordinary port land cement. It is used for mass concrete works such as dams etc.

9. A clay specimen has an unconfined compressive strength of 240 Kn/m2 in a distributed state. On remolding, the unconfined compressive strength is 54 Kn/m2. What will be the sensitivity of clay?

A) 3.85
B) 7.24
C) 2.04
D) 4.44

Answer is D)
Explanation: Sensitivity, St = QU(undistributed)/QU(distributed) =240/54 =4.44.

10. The structural collapse for a clay soil usually occurs at __________

A) First saturation
B) Last
C) Does not occur
D) At an intermediate

... Answer is A)
Explanation: As there is a sudden compression of the soil under pressure, the structural collapse occurs upon first saturation.