Earth Pressure and Retaining Wall MCQs

Question 16Easy

The angle of repose of a soil is the maximum angle which the outer face of the soil mass makes:

Answer: A. with the horizontal

Angle of repose = the steepest angle to the horizontal at which a loose, dry soil heap stands by itself.

Question 17Easy

Which of the following represents the expression for the passive earth pressure coefficient?

Answer: A. tan²(45° + φ/2)

K_p = tan²(45° + φ/2) = (1 + sin φ)/(1 − sin φ).

Question 18Easy

The internal angle of friction of a soil is 30°. What is the active earth pressure coefficient for the soil mass?

Answer: C. 0.333

\(K_a = (1 - \sin30^\circ)/(1 + \sin30^\circ) = 0.5/1.5 = 0.333\).

Question 19Easy

What is the assumption made about the back of the wall in Rankine's theory of earth pressure?

Answer: D. Vertical and smooth

Rankine assumes the back of the wall is vertical and smooth (no wall friction).

Question 20Easy

The coefficient of active earth pressure for a loose sand (cohesionless soil) having an angle of internal friction φ is:

Answer: B. (1 − sin φ)/(1 + sin φ)

K_a = (1 − sin φ)/(1 + sin φ).

Question 21Medium

The effect of cohesion on a soil is to:

Answer: C. reduce active earth pressure intensity but increase passive earth pressure intensity

Bell's equations: \(p_a = K_a\gamma z - 2c\sqrt{K_a}\) (reduced) and \(p_p = K_p\gamma z + 2c\sqrt{K_p}\) (increased).

Question 22Easy

The coefficient of earth pressure at rest is given by (μ = Poisson's ratio):

Answer: B. μ/(1 − μ)

With zero lateral strain, elastic theory gives K₀ = σ_h/σ_v = μ/(1 − μ).

Question 23Easy

The coefficient of passive earth pressure for a cohesionless granular soil is represented by:

Answer: A. (1 + sin θ)/(1 − sin θ)

K_p = (1 + sin θ)/(1 − sin θ), where θ is the angle of internal friction.

Question 24Easy

Rankine's theory for active earth pressure is based on the assumption that:

Answer: D. All options are correct

All three statements are assumptions of Rankine's theory.

Earth Pressure and Retaining Wall MCQs – Part 2