Vertical stresses below a footing 1

[FixedEarth]

I sometimes encounter a shallow foundation that has a finite layer of suitable soil below it and then underlain by soft Clay. I am trying to use the Boussinesq equations to generate footing stress contours in color beneath the footing. This way, I can see the stress at the top of the soft clay below the center of the footing and at the edge of the footing. So it will need to to generate "onion like bulbs". Any ideas how this can be done in any low cost calculation tool? Thanks.

 

[IDS]

Assuming you know how to apply the Boussinesq equation:

[ul]
[li]Calculate stresses along vertical lines over the region of interest.[/li]
[li]Interpolate to find the depth of stress at each of the contour intervals of interest.[/li]
[li]Plot the results on an XY graph with the outline of the footing and the bottom of the layer.[/li]
[/ul]

The tricky bit would be doing the interplation and choosing the right points to connect. For a one off you could do it by hand, but if you want something automated it would probably need a bit of VBA.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[FixedEarth]

Thanks Doug. I will try it.

 

[IDS]

For Excel interpolation functions that can be used for this exercise see:

http://newtonexcelbach.wordpress.com/2012/06/26/interpolation-update-2/

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/