Foundation Design Examples

Bearing Pressure in Shallow Foundations

Example 2 - Calculating the bearing pressure on a continuous footing subjected to a vertical wall load

A continuous footing that is 0.75 m wide supports a vertical wall loading of 120 kN/m.  The distance from the ground surface to the bottom of the footing is 0.6 m.   If the groundwater table is 15 m below the ground surface, calculate the bearing pressure.

Example 4 - Calculating the bearing pressure on a continuous footing subjected to vertical load and overturning moment

The mat foundation shown in the figure below has a width of 50 m, length of 75 m, and thickness of 1.5 m. The combined column and wall loads is 1000 MN. Calculate the average bearing pressure.

Retaining Walls

Example 1 - Calculating the Factor of Safety for Overturning and Sliding, Semigravity Retaining Wall

For the semigravity plain concrete retaining wall shown below, calculate the factor of safety against overturning and sliding given the following parameters:

 

Cohesionless soil

Weight of Backfill: 110 lbs/ft^3

Angle of Internal Friction for Soil: 35 degrees

Coefficient of Friction Between Concrete and Soil: 0.45

Weight of Plain Concrete: 145 lb/ft^3

Example 2 - Calculating the Factor of Safety for Overturning and Sliding, Cantilever Retaining Wall

For the reinforced concrete cantilever retaining wall shown below, calculate the factor of safety against overturning and sliding given the following parameters:

 

Cohesionless soil, c = 0

Weight of Backfill: 110 lbs/ft^3

Angle of Internal Friction: 30 degrees

Coefficient of Friction Between Concrete and Soil: 0.5

Weight of Reinforced Concrete: 150 lb/ft^3

Example 3 - Calculating the Factor of Safety for Overturning and Sliding, Cantilever Retaining Wall with Surcharge Loading

For the reinforced concrete cantilever retaining wall shown below, calculate the factor of safety against overturning and sliding given the following parameters:

 

Cohesionless soil, c = 0

Uniform Surcharge Load: 150 lb/ft^2, extends along entire length of the wall

Width of Surcharge Load: 10 ft

Unit Weight of Backfill: 110 lbs/ft^3

Angle of Internal Friction: 30 degrees

Coefficient of Friction Between Concrete and Soil: 0.5

Weight of Reinforced Concrete: 150 lb/ft^3