Information presented on this page is intended to demonstrate the section design convergence of CSA A23.3 provisions for isolated foundations that can be achieved with SkyCiv. All examples are referenced from the following books:
Book 1: Svetlana Brzev and John Pao. Reinforced Concrete Design: A Practical Approach, 2009.
Example # 1 Design of Axially Loaded Isolated Footing
reference: Book 1, p.605.
DESCRIPTION
A typical cross-section of a square-shaped spread footing supporting a 500 mm square concrete interior column is shown in the figure below. The column carries a specified dead load of 1000 kN and a specified live load of 1000 kN. The allowable soil bearing pressure is 250 kPa.
GEOMETRY AND MATERIAL PROPERTIES
Figure 2: Footing model and material properties of example #1
LOADING
Two static loads cases are considered:
\( \text{D} = 1000 \text{ kN} \)
\( \text{L} = 1000 \text{ kN} \)
The results of service and factor load combination are in computed in reference of NBCC 2010.
ANALYSIS
The analysis is done using the rigid conventional method. See the Isolated Footing User Manual for more explanation on using SkyCiv Foundation.
RESULT COMPARISON
The most significant results are compared in the table below:
| Results | ||
|---|---|---|
| Parameter | Book Reference | SkyCiv |
| Loads | ||
| SLS | 2000 | 2141.01 |
| ULS | 2750 | 2926.26 |
| Soil Pressure | ||
| qf | 305 | 325.14 |
| One way shear | ||
| Actual Shear | 640 | 725.47 |
| One Way Shear Capacity | 730 | 753.7 |
| Two way shear | ||
| bo | 4.1 | 4.2 |
| Punching shear force | 2750 | 2567.8 |
| Two Way Shear Capacity | 2734.29 | 2852.8 |
| Flexure | ||
| Actual Moment | 715 | 762.05 |
| Moment Capacity | 715 | 797.66 |
Notes: Discrepancies on some values are due to the following:
*Actual self weight of column and footing are considered in SkyCiv. In addition, SkyCiv requires a column height greater than zero.
*SkyCiv calculates actual measurement of the effective depth for both directions.
SkyCiv Foundation module offers an innovative and user-friendly interface for the design and analysis of an isolated footing in accordance with CSA A23.3-14.
Want to try SkyCiv’s Foundation Design software? Our free tool allows users to perform load-carrying calculations without any download or installation!
