Unreinforced Plug Pile

[toluun]

I am working on a soil retaining system consisting of structural drilled shafts spaced 1 Dia apart and plug piles in between each structural pile. The plan is for the plug piles to be shorter (just below scour depth) and unreinforced. I have seen this done in several states and is typically acceptable as the plug piles carry no load due to soil arching, at least in my mind. However, I am having some trouble with our DOT due to concerns of Temp & Shrinkage cracking. My response was that cracking wasn't of major concern as 1. These are non-structural piles due to soil arching and 2. There is no reinforcement to corrode if cracks do form. Does anyone know of any aci/aashto publications that address unreinforced plug piles similar to this?

 

[Settingsun]

Sounds like a secant pile wall in this regard. Should be lots of references once you know the magic word to search for.