basic seismic design on any given tank

[biofueler]

I am investigating using used aboveground storage tanks for biofuel. The catch is that the building department requires horizontal force calculations on any aboveground fuel tanks installed (we are in california, seismic zone 3). Manufacturers will typically provide seismic calcs for holddown brackets with new tank purchase. However, manufacturer info is usually hard to come by in teh used tank market. I was wondering if theres anywhere I could get someone to do the calculations for me. I have a background in civil engineering, and understand the concepts and can provide the required dimensions, thicknesses and other details on it to aid in calculations. I dont however have the background in seismic design or a wet stamp. Anybody out there that can help or offer some advice?

 

[damstructural]

I happen to be in California Zone 3 and could probably help you with this, but I'd be leary of using my stamp on used tanks for what may be a hazardous material. I suggest working with the manufacturer to find the correct lateral force resisting system designed for that tank. Good luck.

 

[biofueler]

any advice or assistance would be appreciated, with or without the stamp. for the record, biodiesel is a non-toxic, non-flammable material classified as non-hazardous by the EPA and DOT. The difficult part is the lack of manufacturer info or assistance with used tanks.

 

[Lucifer67]

I am unsure which code will have jurisdiction on your tanks but would hazard a guess at API 650?

This contains a resonably section on seismic design but to be honest would be somewhat lacking in terms of California's performance based seismic design. You may need to consider the effects of vertical earthquakes etc.

First of all you must establish which code has jurisdiation; the starting point would be finding out which codes the original tanks were designed to.

Then you need to establish the current design code, carry out a gap analysis and presumably carry out an inspection etc to re-certify the same.

There are a number of outfits in the US that can assist in this exercise.

What sort of size are we talking about?

 

[biofueler]

10000-30000 gallon

 

[damstructural]

Biofueler, sorry if I discouraged you in any way. Is this a vegatable oil based diesel? If its non-flammable and non-hazardous I wonder what code you would be covered by. Whatever it is, I would imagine they will want to see an engineer's stamp on this. If not, I'll keep advising for whatever its worth to you.

Would have to see plans or sketches of the tank geometry to design proper holdowns and foundation. Would be concerned about stress concentrations on any thin-walled areas of vessel. There should be some parts that are designed to accept the lateral and vertical connections.