Objective Question & Answer

Statement I: Correct

According to Coulomb's Earth Pressure Theory:

· The retaining wall can have a vertical or inclined back face.

·  Wall friction is considered in the analysis.

· The wall surface may be rough, and the friction angle between the wall and soil

is represented by δ.

Therefore, Statement I is correct.

Statement II: Correct

According to Rankine's Earth Pressure Theory:

· The failure surface is assumed to be planar for the classical homogeneous,

cohesionless backfill case.

· The failure plane makes an angle with the horizontal.

For the active state

Statement III: Incorrect

 In Rankine's theory, soil reaches a state of plastic equilibrium in both active and

passive earth

pressure conditions, not only in the active condition.

· Active State: Soil reaches plastic equilibrium when the wall moves away from the

backfill.

· Passive State: Soil reaches plastic equilibrium when the wall moves towards the

backfill.