shear cone - rack leg

[dgkhan]

We have racks on slab on grade. The rack legs or posts has 3x3 inches steel base plates. We need to check if SOG will not shear out. Any idea. Can we use punching or two way shear method

 

[nutte]

Check out this article from Structure magazine, which proposes a method for exactly your case. You'll need to know, or at least be able to estimate, the modulus of soil reaction.

http://www.structuremag.org/article.aspx?articleID=613

http://www.structuremag.org/Archives/2008-4/C-StructuralDesign-Azzi-Apr08.pdf

 

[OHIOMatt]

I have been involved in testing 6" unreinforced slabs for axial compressive loads. A similiar sized baseplate resulted in measured deflections of less than 1/32" under a 40 kip load. There were no visible cracks.

As a side note, we did have a relatively stiff subgrade.