12.13 through 12.15 A retaining wall is shown in Figure 12.44. For each problem, determine the Rankine active force, Pa, per unit length of the wall and the location of the resultant. Surcharge = q ↓ H H₁ Frictionless wall Sand 71 Problem H 12.13 10 ft 12.14 20 ft 12.15 6 m cí Sand 72 (saturated unit weight) c₂=0 Groundwater table H₁ 5 ft 6 ft 3 m Y₁ 105 lb/ft³ 110 lb/ft³ 15.5 kN/m³ Y2 122 lb/ft³ 126 lb/ft³ Figure 12.44 19.0 kN/m³ (deg) (deg) 30 30 34 34 30 36 q 0 300 lb/ft³ 15 kN/m³