- Polygon: defines the extent of the base of the foundation
- Load point (LP): defines the point of application of the vertical load
- Center of gravity (CG): defines the CG of a polygon
- Neutral axis (NA): defines the line of zero stress for the reduced polygon
Simple example of a rectangular footing showing reduced bearing area
- Reduced polygon: defines the effective portion of the base of the foundation
- Quadrant: mathematics term
The user enters:
- the coordinates of a polygon, in clockwise or counterclockwise order
- the load point
The method of analysis is iterative.
The iterative method requires that the polygon be located in the first quadrant of the plane. The program takes care of that internally; the user can locate the polygon on any XY coordinate system.
The CG of the input polygon is calculated.
Within the polygon, the iterative procedure will tend to converge if the LP is such that
that is, if the LP is lower left of the CG.
Internally, therefore, the program must rearrange the coordinate system to place the load point in the as-needed position. Turns out there are 8 possible transformations for an XY coordinate system (right click image to see in separate tab).
After the iteration is complete, the program returns:
- the load point
- the input polygon
- the input polygon CG
- the input polygon area
- the neutral axis of the reduced polygon
- the reduced polygon
- the reduced polygon CG
- the reduced polygon area
- the reduced area ratio
Hover over chart elements to see analysis results.
Click legend elements to toggle on an off.
Static Charts (right click chart to see in separate tab)