Geotechnical Engineering Questions and Answers – Active Earth Pressure: Rankine’s Theory

Geotechnical Engineering Objective Questions

Civil Engineering MCQs

This set of Geotechnical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Active Earth pressure: Rankine’s theory”.

1. Originally, Rankine’s theory of lateral earth pressure can be applied to only _______

A) Cohesion less soil
B) Cohesive soil
C) Fine grained soil
D) Coarse grained soil

Answer is A)
Explanation: As originally proposed, Rankine’ s theory of lateral pressure is applied to uniform cohesion less soils only. Later, it was extended to include cohesive soil.

2. Rankine’s theory of lateral pressure was extended to other soil by __________

A) Resal and Bell
B) Mohr
C) None of the mentioned
D) All of the mentioned

Answer is A)
Explanation: The theory of lateral pressure was extended to cohesive, stratified, partially immersed and submerged soil was by Resal in 1910 and by Bell in 1915.

3. Based on the assumptions of Rankine’s theory, the soil mass is __________

A) Stratified
B) Submerged
C) Homogeneous
D) All of the mentioned

Answer is C)
Explanation: According to the assumption of Rankine’s theory, the soil mass is semi-infinite, homogeneous, dry and cohesion less.

4. Which of the following cases for cohesion less backfill in Rankine’s theory is considered?

A) Submerged backfill
B) Moist backfill with no surcharge
C) Backfill with sloping surface
D) All of the mentioned

Answer is D)
Explanation: In Rankine’s theory the following cases of cohesionless backfill are considered i) Dry or moist backfill with no surcharge ii) Submerged backfill iii) Backfill with a sloping surface and inclined back and surcharge.

5. The factor that is responsible for inclination of resultant pressure to the retaining wall is __________

A) Frictional force
B) Surcharge
C) Earth pressure
D) Weight of the wall

Answer is A)
Explanation: The retaining walls are constructed of masonry or concrete, due to this the frictional force develops. The existence of the friction makes the resultant pressure inclined to the wall at an angle that approaches the frictional angle between the soil and the wall.

6. If the sand filled behind the retaining wall with saturated water with water, then the possible lateral pressure is __________

A) Lateral pressure due to submerged weight and Lateral pressure due to water
B) Lateral pressure due to retaining wall
C) None of the mentioned
D) All of the mentioned

Answer is A)
Explanation: The lateral pressure is made up of two components for wetted soil in back of the retaining wall: i) Lateral pressure due to submerged weight ‘γ’ of the soil, and ii) Lateral pressure due to water.

7. The earth pressure at rest exerted on a retaining structure can be calculated using __________

A) Theory of plasticity
B) Theory of elasticity
C) Mohr’s theory of rupture
D) None of the mentioned

Answer is B)
Explanation: The earth pressure at rest, exerted on the back of the rigid, unyielding retaining structure, can be calculated using theory of elasticity.

8. The value of K0(coefficient of earth pressure at rest) for loose sand is __________

A) 0.6
B) 0.5
C) 0.4
D) 0.8

Answer is C)
Explanation: The value of K0 for different soils is: i) Loose sand – 0.4 ii) Dense sand – 0.6 iii) Soft clay – 0.6 iv) Hard clay – 0.5.

9. The expression for K0 as given by Jacky is ___________

A) K0 = 1 – sin φ
B) K0 = sin φ
C) K0 = 1 – cos φ
D) K0 = 1 + sin φ

Answer is A)
Explanation: K0 can be calculated by using the following equation as computed by Jacky in 1944: K0 = 1 – sin φ.

10. What will be the coefficient of earth pressure at rest for a rigid retaining wall, If the backfill consists of cohesion less soil having φ = 26°?

A) 0.1295
B) 0.6552
C) 0.5616
D) 0.7383

... Answer is C)
Explanation: Coefficient of earth pressure, K0 can be calculated using Jacky’s formula: Given: φ = 26° Formula: K0=1 – sin φ K0 = 1 – sin 26° K0 = 1 – 0.4383 K0 = 0.561628.