Learning Forum

[peteroznewman]

Hello Zoltan,

I found this YouTube video on an analysis of a buried water tank. The first few minutes show all the loads that need to be considered. The video shows a load called surcharge loads, which was unfamiliar to me, but I found this article that explains it.

You need loads from both the soil and the water in the tank. The analysis needs to consider at least three load cases.

1. Tank full before being buried (leak test).
2. Tank empty and buried.
3. Tank full and buried.

When the buried tank is empty, there is only pressure on the outer wall, but when the tank is full of water, the hydrostatic pressure of the water in the tank cancels out some of the pressure on the outside of the tank.

One way to apply soil pressure is to mesh a block of soil that has a tank-shaped cavity. Ansys includes soil models such as Mohr-Coulomb. This will complicate your model so it is easier to apply loads instead.

Here are 3 videos that cover the loads on a tank buried in soil.

1. Part 1
2. Part 2
3. Part 3