For a retaining wall,
- AThe shear resistance developed along the failure surface is a minimum when the active conditions develop
- BCoulomb’s theory always gives conservative values
- CThe active pressure increases if a dry soil becomes submerged
- DThe basement walls are generally designed for at-rest pressureCorrect
Solution
Concept
Earth pressure states
Step-by-step solution
1. Basement walls are restrained against movement, so they are designed for at-rest pressure. 2. A is the opposite (at active state the shear resistance is fully mobilised); B is not always true; C is true only when the unit weight/pressure changes, not stated generally.
Explanation
Rigid, braced basement walls cannot move enough for the active state.
Why the other options are wrong
The other statements are not generally correct.
Shortcut
Basement wall → at-rest pressure.
Correct answer: D) The basement walls are generally designed for at-rest pressure