More Retaining Wall Calculations

A detailed structural analysis of a reinforced concrete retaining wall using Eurocode design principles.

1. Input Parameters:

• Soil Properties:
  • Friction angle (?) = 30 degrees
  • Cohesion (c) = 0
  • Soil unit weight (?b) = 18 kN/m³
  • Concrete unit weight (?c) = 25 kN/m³

2. Wall Dimensions:

• Wall height (H) = 6m
• Wall thickness (w) = 1m
• Footing width (B) = 7m
• Footing thickness (v) = 1m
• Toe width (t) = 2m
• Heel width (h) = 4m

3. Key Calculations: a) Forces Considered:

• Variable loads (surcharge)
• Self-weight of wall components
• Active earth pressure
• Soil weight over heel

b) Stability Checks:

1. Sliding Check:

2. Overturning Check:

3. Bearing Capacity Check:

• Uses Meyerhof's method
• Considers shape factors, depth factors, and inclination factors
• Results: 20% utilization for A1 and 52% for A2

The pile design calculation for the retaining wall foundation:

1. Pile Configuration:

• Diameter = 0.3m
• Reinforcement = 6 × Y12 bars (0.96% of concrete area)
• Edge clearance = 0.1m
• Lever arm (La) = 3.25m
• Spacing: 1.2m along toe, 1.45m along heel

2. Load Distribution:

3. Individual Pile Loads:

4. Ultimate Bending Moment Resistance:

• Uses CP110 design interaction charts
• Calculated using normalized parameters (N/h²)
• Front Pile Mr,T: A1 = 41 kN-m/pile, A2 = 38 kN-m/pile
• Rear Pile Mr,H: A1 = 41 kN-m/pile, A2 = 36 kN-m/pile

5. Horizontal Resistance:

• Uses Broms' method for lateral pile capacity
• Considers soil parameters:
  • Sand density = 18 kN/m³
  • No cohesion
  • Friction angle: A1 = 30°, A2 = 24.8°
  • Passive coefficient (Kp): A1 = 3.00, A2 = 2.44

6. Design Check:

The high utilization ratios (>100%) suggest that the pile design may need revision - either by increasing pile diameter, spacing, or reinforcement, as the horizontal loads exceed the calculated resistance.