Cantilever retaining wall analysis.xls

 Purpose of calculation: The details of a cantilever retaining wall are shown below, is the design of the wall satisfactory?    
    
Calculation Reference: Craig Soil Mechanics. R.F. Craig    
    
Calculation Validation: Check against a worked example in the reference above.    
    
Calculation Parameters    
    Surcharge Pressure
    Thickness of the Stem
    Thickness of the Base
    Length of Backfill
    Height of Wall from the Base
    Width of the Base
    Characteristics of Backfill
    Drained (effective stress) Shear Strength Parameter
    Unit Weight of the backfill
    Drained (effective stress) Shear Strength Parameter
    Characteristics of Concrete
    Unit Weight of Concrete
    Angle of friction between the base and the foundation soil is
    Active earth pressure coefficient
    Horizontal Forces
    Sum of Horizontal Forces
    Vertical Forces
    Sum of Vertical Forces
    Lever
    Moments
    Lever arm of base resultant
    FoS against overturning
    Eccentricity of base reaction
    Maximum and minimum base pressures
    FoS against sliding

Calculation Reference
Geotechnics

Soil Mechanics

Craig's Soil Mechanics

The analysis of a cantilever retaining wall following Craig's Soil Mechanics involves the following steps:

1. Determine the soil properties, such as the soil type, unit weight, angle of internal friction, and cohesion.
2. Determine the dimensions of the retaining wall, including the height, base width, and toe length.
3. Determine the design loads, which include the soil pressure, water pressure, surcharge loads, and any other loads that may act on the wall.
4. Determine the depth and width of the foundation required to support the wall.
5. Calculate the active earth pressure using one of the following methods: a. Coulomb's wedge theory, which assumes that the soil above the wall moves as a wedge. b. Rankine's theory, which assumes that the soil above the wall moves as a block. c. The pressure distribution method, which assumes that the soil pressure varies linearly with depth.
6. Calculate the passive earth pressure using one of the following methods: a. Coulomb's theory, which assumes that the soil below the wall is stationary. b. Rankine's theory, which assumes that the soil below the wall is mobilized.
7. Determine the required reinforcing steel for the retaining wall based on the design loads and the wall dimensions.
8. Prepare construction specifications and drawings for the retaining wall.

The analysis of a cantilever retaining wall can be further refined by considering other factors, such as the presence of groundwater, the effect of soil stratification, and the effect of soil consolidation. The analysis can also be performed using computer software or spreadsheet programs, which can provide more accurate and efficient results.

Overall, the analysis of a cantilever retaining wall following Craig's Soil Mechanics provides a rigorous and systematic approach to design and construct retaining walls that can support the required loads and ensure the stability and safety of the structures.