An isolated footing is one of the most used types of foundation to support single-columns when they are arranged at a long distance. An isolated footing must be designed to avoid exceeding its bearing capacity and provide safety against overturning or sliding while preventing the ground from settling.
Density Of Concrete
Density Of Soil
Depth Of Foundation
Soil Bearing Capacity
Length Of Footing
Width Of Footing
Thickness of Fdtn.
Width Of Pedestal
Length Of Pedestal
Height Of Pedestal
Coefficient Of Friction
Ground Water Table Ht.
1.0 Load Calculation for Footing & Soil:
Self Wt. Of Footing
Weight of Soil
Self Wt. Of Pedestal
Weight of Footing + Soil
2.0 Check Maximum and Minimum Pressure at Footing Base:
Area of Footing
Section Modulus
Section Modulus
Total Vertical Load
3.0 Check for Overturning:
Overturning Moment
Due to External Load
Due to wt. of Pedestal
Due to Self Wt. of Fdn
Due to Wt. of Soil
Total Stabilizing Moment
F.O.S. against Overturning
4.0 Check for Sliding:
Resultant Shear Force
Total Vertical Load
F.O.S. against Sliding
5.0 Load Case Check:
Check Max. & Mini. Pressure at Footing Base:
6.0 Check for Overturning & Sliding:
7.0 Check For Shear
a) Two Way Shear
b) One Way Shear
8.0 Design Of Foundation/Footing:
a) Calculation of Reinforcement at Bottom
b) Calculation of Reinforcement at Top
This presents the design of isolated spread footing using the results from Staad Support Reactions.
Calculation Reference
Reinforced Concrete Footings
The footings were proportioned so that the bearing pressure does not exceed the safe bearing capacity of the soil. The bending moments and shears are determined at critical sections. The calculation follows methods set out in ACI 318-08.
Calculation Reference
Reinforced Concrete Design
