Pond Boss Forums INTRO Questions & Observations What pier diameter for dock

I'm hoping to use some Sonotubes to pour some concrete piers for my dock and was wondering what diameter they ought to be? I'd like to pour this myself without having a concrete truck come in, I have a pretty good mixer, so I'm hoping to not go overboard on the diameter. The dock would be a simple rectangle, about 15' X 6', nothing fancy. The deepest piers would be about 10' to the mud line.

A relative of mine was telling me that the ice on the lake development he lives on sheared his concrete piers off at the water line a couple of winters ago. He said it was because of the diameter but I'm not sure what he said they were. I also don't know if he used any reinforcement or if it would have made any difference even if he had, if the diameter was too small anyway.

We don't get a lot of long term freezes in the winter here but we occasionally get an arctic blast that might last a couple of weeks.

Also, for reinforcement should I use wire or rebar?

Thanks!