Slab on Grade - Interior vs. Exterior/Corner Loaded Condition

[Strengi]

For slabs on grade, most of the design methodologies (those in ACI 360) assume an interior loaded condition for concentrated wheel/post loads. Even with looking at the document "Load Testing of Instrumented Pavement Sections - Improved Techniques for Applying the Finite Element Method to Strain Prediction in PCC Pavement Structures" (available for free download), it defines interior loading as being "considerable distance from the edge or corner". There doesn't seem to be a definitive distance that an interior loaded condition needs to be set away from an exterior/corner loaded condition.

My question is this - how far from an edge/corner does a slab need to be thickened before it can be reduced to the interior loaded condition? Any help would be appreciated. As always, thanks in advance.

 

[dik]

If you can get a copy of "Concrete Industrial Ground Floors" by the Concrete Society, Tech Report 34, it has a pretty good discussion about point loads located near edges of slab and corners at intersection.

Dik