Storage Tank - Foundation Recommendations
Storage Tank - Foundation Recommendations
(OP)
Hello All:
I am a structural engineer and have been recently assigned with the job of designing the foundation for a water storage tank (26' dia x 35' high).
From my online/literature research I see that the options for the tank foundation are either a crushed stone ringwall or a concrete ring wall or a reinforced concrete slab.
A question I have to my fellow engineers is: Who makes the call or recommends the type of foundation suitable for the tank? Is it the Geotechnical Engineer or the Structural Engineer?
My hunch is that that the Geotechnical Engineer must advise on the type of foundation (one of the above mentioned types)and shoud not just state in his/her report that a shallow footing is recommended for the structure at the site.
Thank you for your comments/advise/opinion.
I am a structural engineer and have been recently assigned with the job of designing the foundation for a water storage tank (26' dia x 35' high).
From my online/literature research I see that the options for the tank foundation are either a crushed stone ringwall or a concrete ring wall or a reinforced concrete slab.
A question I have to my fellow engineers is: Who makes the call or recommends the type of foundation suitable for the tank? Is it the Geotechnical Engineer or the Structural Engineer?
My hunch is that that the Geotechnical Engineer must advise on the type of foundation (one of the above mentioned types)and shoud not just state in his/her report that a shallow footing is recommended for the structure at the site.
Thank you for your comments/advise/opinion.





RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
Be aware that posting questions to multiple forums is frowned upon. It seems that you are new, so this is understandable.
RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
My apologies for posting it on two forums as I wasn't aware of the etiquette and this will not happen again ... all i was trying is to get the opinion of both structural and geotechnical engineers ...Thank you Weab for bringing it to my attention.
RE: Storage Tank - Foundation Recommendations
Since I am in a seismically active area, I consider your tank to be very tall for its diameter. We usually shoot for the diameter to be at least 2x the height (my tanks have ranged from 1.3x to over 4.0x). I know that in other areas tall cylinders are used, but around here its not common.
If you're in a seismically active area this tank will be subject to overturning and I'm pretty sure it will need to be anchored (in Zone 4 it definitely would need to be anchored). The only tank I have anchored is the 1.3x aspect ratio tank, and it was anchored to a ringwall, which in turn was anchored to the rock beneath.
Another thing to consider in seismic areas is sloshing of the water. That enters into determining the required freeboard (distance between maximum water level and underside of the roof structure).
==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill
RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
RE: Storage Tank - Foundation Recommendations
I agree that certain meter of extention of gravel beyond the tank edge can replace the ring wall. I believe the extension is not only for distributing the stress induced by the tank in such that it meets the original soil bearing pressure, but also to provide confinement to the stressed gravel.
Regardless of the above, ring wall has an advantage that it can be specifically designed to provide inward radial pressure for balancing certain tank load.