Q4) for retaining wall shown in Figure No. 3. Find the following: 1 m+ SandSoil W1 Y=18 kN/m3 p=30° 5.5 m Concrete Yc=24 kN/m3 1 m W2 Clay Soil Ca=60 kN/m? p=0° B- 1-Width of base (B) if factor safety of sliding = factor safety of overturning 2-Find friction angle under base if factor safety of sliding = 1 and Ca=0

3. Compute the resultant lateral force for the soil-wall system shown in Figure 3. You may ignore tensile cracks. Use • A- Coloumb • B - Rankine 0=30°, y=20kN/m³ 4m Ground water table 7m c=50KN/m², p=10°, y=18KN/m³ 0=25°, y=20KN/m³ 8 m Gravity wall Figure 3

The following figure shows a section of an anchored retaining wall embedded into a saturated stiff clay layer. The sand has a unit weight of = 18 kN/m³, c' = 0 kPa and o' = 34º. The clay has a unit weight of = 20 kN/m³, c₁ = 80 kPa and = 0°. A uniform pressure of 40 kPa is applied on the soil surface. The short term stability of the wall is considered in an undrained analysis. Use the Rankin's theory of lateral earth pressure to determine the active and passive horizontal stresses. You should apply the requirements of AS 4678 and the partial factors of safety method in estimation of soil pressures. Assume the soil is in-situ and use a structural classification factor of ₁ = 1. 3m 1m Water table 1.5m 40 kPa Not to Scale Sand Clay Ta

You are reviewing the stability of the gravity wall when the backfill has properties with: Φ' = 35° and γt = 16.5 kN/m3. The soils in front of the wall is ignored in the stability analysis, and the drainage blanket has no influence. Assume the coefficient of the base friction is, μ = 0.3, and the unit weight of concrete is γc = 23.5 kN/m3. a) draw the lateral earth pressure diagram and determine the total active lateral force. b) determine the factor of safety against overturning. c) determine the factor of safety against sliding.