Removing a section of wall from storage tank 2

[rpierce100]

A client needs to remove a section of vertical wall from an above ground storage tank. The tank is 60 feet diameter x 30 feet high. The section to be removed is at grade 8 feet high x 12 feet of circumference. Is there a reference I could use to calculate the stress on the remaining wall and how to design a temporary stiffening frame. The removed wall sect will be replaced by a new section.

 

[JedClampett]

Is this tank steel or concrete?

 

[rpierce100]

The tank is carbon steel plate. At this point I do not know the thickness.

 

[JedClampett]

You need to weld a frame made of structural sections to the shell to carry wind and the plate dead and any roof live load load. If you don't know how to do the calculation yourself, call a local steel tank manufacturer and ask them who they use to do their calculations and punt it to them.
After the work is complete, a new plate of the same original thickness (or greater) needs to be full penetration butt welded into the opening.

 

[Ron]

Agree with JedClampett...in addition, check the relevant code for the tank, such as AWWA for water, API for petroleum, etc.

This is done routinely by tank builders. In fact, there was probably a similar opening in the tank during construction. One caution about circular openings in a circular tank....make sure the reinforcing frame gets carried far enough away from the opening that "oil canning" doesn't happen (plate will buckle around the opening, making replacement of the shell piece very difficult).