Fuel Tank Ringwall Frost Considerations

[H57]

I am in the process of designing a foundation for a large fuel tank. Because of it's location the frost depth is given as 6 feet. I was conisdering using a ring wall footing with the interior of the ring wall being replaced with non frost susceptible fill. Both the ring wall and the fill will be taken to a depth of 6 feet. The ring wall is 18" thick. Should additional provisions be made to protect the tank from heaving or is the replacement of the interior soil adequate?

 

[ishvaaag]

You may take the same precaution outside the ring, and a cantilever from the foundation bridge the infill. Make a study on if any potential heave or settlement (or steady state worse case temperature effect?) needs be treated mechanically or otherwise. Drainage can also be useful for the control of the variation of water presence in the environment of the tank.

 

[JStephen]

I'm not aware that anything special is normally done even for the fill inside the ringwall. There's not normally a way for large amounts of water to get into that area, and the tank and contents would provide a certain amount of thermal protection as well. Some of the heavier fuel oils have to be heated, for that matter. You might also check App. B to API-650 for recommendations.

 

[hokie66]

I suggest you google this site for discussions of tank foundations. There have been a lot of threads. Ring walls are not the only solution, and may not be the best solution for your application. I suggest that if you have 6' of fill, you may not need the ring wall.

 

[msquared48]

Do you have permafrost to deal with too?

Mike McCann
MMC Engineering