Vertical Subgrade Modulus - Aggregate Piers

[nbr1]

What is the methodology for determining the vertical subgrade modulus for a mat foundation supported on aggregate pier
reinforced soils in clay; assuming shallow piers...say 20 feet, and a relatively deep clay soil profile...say 50 feet.
Is there a way of assigning an elastic modulus to the soil layers and converting to an equivalent k-value?

 

[JedClampett]

Have you asked the aggregate pier supplier's engineering staff? They're very knowledgeable of their product and if it's of use to anyone, they probably have an answer.

 

[Mccoy]

Conversion can be done simply by the definition of K, that is K=load/settlement, whereas assigning reliable elastic moduli requires in situ or lab tests though, a more recent way to acquire this parameter is by geophysical surface and down the hole methods.
The staff may assign values by a priori statistical knowledge although a value of uncertanty should be assigned as well