Settlement of circular tanks using ring beam foundation

[SuperSandman]

I am trying to calculate the settlement at the edge of a circular tank. The foundation comprises ground improvement with the inclusion of a ring beam beneath the tank wall. Normally I calculate the total settlement of the tank using the tank diameter(B). I need to determine the edge settlement of the tank but I am not sure as to how I should treat the load that the ring beam is transferring to the ground. Am I correct by saying that the edge settlement is a function of the width of the ring beam?

 

[Ron]

Very little of the tank load contributes to settlement of the ring wall. It is there to support the wall and roof dead loads (assuming no center column) and provide lateral confinement for the bearing soils that support the tank.

 

[JedClampett]

Agree with Ron. Plus it's meant to be sized so that its loads are similar to the tank loads. So it will settle about the same.
My old Gaylord and Gaylord "Structural Engineering Handbook", chapter 23 discusses this. I'll bet if you ask around, someone has a copy of it.