Underground Tanks 2

[PrecastDroopy]

I recently was asked to review a tank for a precaster that has been using this tank since 1947. They have installed countless of these under fast food joints and stores during this time. Not one has failed, or cracked for any reason what so ever. Yesterday a building inspector would not sign of on the tank unless sealed drawings were provided to the county proving that the tank will not fail. After looking at this tank, with a 3" wall, burried 3'-0" below the surface, the wire mesh provided was not even close to the required amount. I used a FEA model to get the moments with the soil loads and such. Any body out there have any idea how to prove this tanks works?
Keep in mind that when it is full the moments on this thing are near zero. This check is only for construction loads, and just prior to filling.

Thanks a bunch.

Chad Van Kampen P.E.

 

[Ron]

Chad...do some proof testing. Load test it in place. You can use a liquid level gauge to check deflection as it will change the volume.

 

[blake989]

the PCA publishes a manual for the design of circular tanks without prestressing and for rectangular tanks. These manuals are basically worked examples with tables for obtaining coefficients used in the design/analysis process.

 

[PrecastDroopy]

This manual you speak of by the (Portland Cement Association, or the Precast Concrete Association?) is hard to find. Does anyone have an expample they could PDF and email it to me?

 

[blake989]

Portland Cement Association, you can find them online by typing that into a search and go to their bookstore. You can buy them individually or as a group, it is much cheaper to buy them as a group ($35 per book or $48 for both). Try the link below and see if it works. In order for you to have all the tables required, and all of the addenda, you really need the manuals instead of an email.

http://www.cement.org/bookstore/profile.asp?store=&pagenum=1&pos=4&catID=&id=1959