PCA circular concrete tanks

[3hills]

Hello, can someone give me a quick explanation.

I've got a tank that gives a h²/Dt = 30 range.

How are the supplementary coefficients used?
They don't explain in the book, and they don't seem to fit in very clearly.
They only cover either top or bottom portions of the tank as well.

Thanks

 

[JedClampett]

For a tall tank, you need more data points at the bottom of a tank. So instead of just .7, .8 and .9, they give you .75. .8, .85, .9 and .95. The affect of the base fixity diminishes for all tanks, but for tall ones, it pretty much disappears.
Above that, just use straight hoop stresses.