The angle of inclination of the failure plane behind a vertical retaining wall in active state is inclined to the horizontal at an angle of
- A45 + φ′
- B45 + φ′/2Correct
- C45 − φ′/2
- D45 − φ′
Solution
Concept
Failure plane in Rankine active state
Formula
θ = 45° + φ/2 from horizontal
Step-by-step solution
1. In Rankine's active state the failure plane makes 45° + φ/2 with the horizontal. 2. In the passive state it is 45° − φ/2.
Explanation
In Rankine's active state the failure plane makes 45° + φ/2 with the horizontal.
Shortcut
Active: 45 + φ/2.
Correct answer: B) 45 + φ′/2