Moving away from the soil, the force:

Falls rapidly to Pa after a small movement (0.001-0.005 H in sand)

Falls only after a large movement

Compared to active, the movement to mobilise full Pp is:

Much larger (0.01-0.05 H in sand)

2078 Bhadra · 2 marks

Wall movement versus earth pressure plot

Short answer

At zero movement, lateral force is the at-rest value P0. Moving the wall away from soil by 0.001–0.005 H (sand) reduces force to active minimum Pa; moving it toward soil by 0.01–0.05 H raises it to passive maximum Pp. Pa < P0 < Pp.

Draw the plot showing the relationship between lateral earth pressure force per unit length of the wall vs. movement of the retaining wall.

The plot shows lateral force $P$ on the wall against wall movement $\Delta$ (away from or toward the soil).

  P (force on wall)
  ^
  |                           _______ Pp (passive, maximum)
  |                        .-'
  |                      .'
  |                   .-'
  |              *-'   P0 at rest (zero movement)
  |           .-'
  |  ______.-'
  |  Pa (active, minimum)
  +--------------+------------------------> wall movement
   away from soil 0      toward soil
   (0.001-0.005H)        (0.01-0.05H)

At zero movement the force is $P_0$ (at rest, $K_0$ ).
Moving away from the soil, the force falls rapidly and reaches the minimum active value $P_a$ after a small movement (0.001-0.005 H in sand).
Moving toward the soil, the force rises and reaches the maximum passive value $P_p$ only after a large movement (0.01-0.05 H in sand; more for clay).
Order: $P_a < P_0 < P_p$ .

✓ Answer checked by Claude Sonnet 5.5

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Wall movement versus earth pressure plot

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