Concrete Tank Corner Reinforcement

[mastruc]

Hello all:

I had a question about how to properly reinforce the corner of a thin-walled rectangular open-topped tank. The tank walls are pretty short (<4'), so a 6" wall looks to be sufficient for strength. At the corners, where the horizontal moments are largest, though, I'm not sure how to properly ensure that the force transfers diagonally across. Attached is a link to a preliminary sketch showing what I have in mind -- ending the horizontal reinforcement with standard hooks, and lapping reinforcement diagonally across a corner chamfer. Then, checking for moment capacity at each end of the chamfer, and at a section cut at 45-degrees, at the center of the corner. Does it look like I'm on the right path with this?

Thanks for any input you might have!

http://i.imgur.com/MyZ193b.png

 

[JedClampett]

Sorry, I'm not opening up any direct links like that as my IT department really frowns on passing viruses that way.
Even though your tank is very small, I'd thicken the walls. I'd use 12 inches. It allows for waterstop to be installed at the base to wall joint. Plus with a six inch wall, if the bars are off a little, you've really derated your wall.
But if you insist on a 6 inch wall, from your description it sounds like you've developed the horizontal steel. We like a lap instead of a hook, but I think they're technically the same capacity.
Be sure to check shear at the base and corners. You only have a "d" of 3 inches and that's not a lot of shear cppacity.

 

[ztengguy]

Im with Jed, no way I am opening that. Could be porn for all we know.

 

[mastruc]

Hi, Jed:

Sorry about the external URL. I've pasted it into the "attachment" box -- I hope that works, I'm new to this forum's design. The narrow wall is desirable from a cost point of view because this is a tank to hold potential spills from an interior fiberglass tank. Any events that result in any stored liquid at all, let alone it being filled to capacity, will be rare if not nonexistent. Thus the drive to make the design as minimal as code allows.

 

[mastruc]

All right, so I'm a damn fool. Here's the image file, hosted on engineering.com.

 

[JedClampett]

I opened your link and it wasn't porn. Darn!
Your detail looks good considering your wall thickness. Since it's a secondary containment, it should be fine.