Foundation for Horizontal Aboveground Storage Tanks

[jim57]

I am designing the foundation for a horizontal aboveground storage tank. It is supported by 2 saddles. My question is do I need to put a perimeter curtain wall down to frost, do I need to place well graded gravel down to frost or can I go with 18 inches of stone. Mat foundation is 12 inches thick and the frost line is 42"
Thanks

 

[jhnblgr]

Place mat foundation below frost grade and use concrete walls to support the saddles.
Alternatively you could go high load insulation shallow foundation design method but really isn’t advisable. I always would recommend removing any soil in the frost line with clean crushed stone without fines, if the soil has moisture it’s going to heave frost wall or not.

 

[jim57]

Thank you. Do we need walls at the saddle or can we just add more rebar in the mat? Do you have a sketch?

 

[JStephen]

Most of the cases I've seen, they had separate supports (footing + rectangular pier) under each saddle.