Design of Strap (Cantilever) Footings
This is a special type of footing used for two columns. The two columns are provided by two separate footings connected by a rigid beam called “strap beam”. The footing areas are proportioned in such away to keep the pressure under the two footings uniform and equal and for the centroid of the combined footing areas to coincide with the resultant of the two column loads. It is assumed that the strap beam is rigid and does not transfer any load by bearing on the soil at
its bottom contact surface.
Summary of strap footing design is shown in the following steps.
The below attached sheet for design of strap footings consist of various examples and calculation's.
This is a special type of footing used for two columns. The two columns are provided by two separate footings connected by a rigid beam called “strap beam”. The footing areas are proportioned in such away to keep the pressure under the two footings uniform and equal and for the centroid of the combined footing areas to coincide with the resultant of the two column loads. It is assumed that the strap beam is rigid and does not transfer any load by bearing on the soil at
its bottom contact surface.
Summary of strap footing design is shown in the following steps.
- Select trial footing depths.
- Proportion footing dimensions.
- Evaluate factored net soil pressure under the footings.
- Design column footings for beam shear and moment.
- Design the strap beam for moment and shear.
- Check bearing strength of column and footing concrete.
- Check chosen reinforcement bars for anchorage.
- Prepare detailed design drawings.
The below attached sheet for design of strap footings consist of various examples and calculation's.
