Clarifier foundation anchor channel

[tben]

Does anyone have a design guide or information on design of an anchor channel for a steel walled clarifier with a concrete base. How is corrosion controlled on the channel and how is the reinforcing in the concrete base designed in the vicinity of the channel.

 

[JedClampett]

Try this

 

[tben]

Thanks for the prompt response!
I was proceeding on an amazingly similar path.
I am assuming the channel will resist any hoop stresses from the tank wall
and the concrete reinforcing will resist the hoop stress developed by the horizontal forces from the sloped bottom?

 

[JStephen]

Unfortunately, there's no standard way to make this connection. What is shown there is fairly typical.
Usually, the weld between channel and shell would be double fillets rather than a groove weld.
You can bump the channel thickness up a size or two if concerned about corrosion.
Normally, this would be used on fairly small diameter and/or low tanks. In that case, the shell is adequate for the hoop stress in it, and the channel is adequate for the hoop stress in it. Theoretically, you'd get some rolling moment at the base and at the connection between channel and shell, but that is not usually considered.
I've seen details with and without a waterstop placed next to the channel. I've seen details where the channel and shell was to be all welded out, then grouted into a groove left in the concrete.

 

[tben]

I appreciate the advice. I am planning to install a waterstop on the channel to reduce product intrusion. Are these channels normally coated prior to being cast in place. I am looking at an epoxy primer to be applied to all but the top flange. This is the same primer for the coating on the tank.

 

[JedClampett]

I'll check what we do. I know I got this from a tank guy who I used to work with, tweaked it slightly and put it out. And my tank buddy won that portion of the project.

 

[JedClampett]

In my final design, I only asked that the channel was to be field coated to match the tank coating. I thought that any shop coating would get beat up anyway. Not to mention that there is a field weld.
I'd worry about the immediate interface between the channel and the concrete, but we do these every once in a while and I've never heard of an issue.

 

[tben]

Thanks for the info.