Calculate the lateral force created by soil pressures acting against a retaining wall having a vertical frictionless backface for the following conditions (ref. Figure 4): • Wall height is 6 m,...

Calculate the lateral force created by soil pressures acting against a retaining wall having a vertical frictionless backface for the following conditions (ref. Figure 4):

• Wall height is 6 m, backface is vertical.

• Cohesionless soil backfill is level, soil unit weight is 17 kN/m³, angle of internal friction is 35°.

(a) Assume the at-rest soil pressure condition.

(b) Assume the active soil pressure condition.

(c) Express the difference between (a) and (b) as a percentage related to the active pressure condition.