Slab-On-Fill question

[Stenbrook]

When designing a slab on grade with drilled piers on expansive soils I have always been taught that you add enough select fill (Per the Geotech engineer) to reduce the soils PVR to 1.0 inch for it to be acceptable. Does anyone know where this acceptance criteria came from? Is it accurate?

 

[Ron]

Check with Prof. Robert Lytton at Texas A&M and also the Texas DOT.

Based on method developed by Chester McDowell who was with the Texas DOT in the 1950's