Recent content by NoName1

profplan, Related to your question about the tension hoop stress, for walls with "significant" tension forces. Check out ACI 350-06 11.3.1.3 & 11.3.2

To answer the "Most Nearly" question, I would say 4 since the steel required is for a beam with capacity to carry the moment. Three (3) does not carry the moment, so it does not matter if that is closest to the calculted number. It just doesn't work. But that most nearly part always throws me...

Thank you for the response.

Splitrings and VTEIT, Sorry to post a question in another post, but i have been wondering about what you brought up. When you reduce the spacing at the corners, is that total amount of steel provided at the corner the amount required by analysis for the moment at the corner and the reinforcing...

Thank you for the responses. So if I have a 6" bar spacing without the opening and (just assuming O.D. is actually 48 inches for discussion)I cut 8 vertical bars. Would I add 4 bars on either side of the pipe between the verticals at 6" so the spacing would be 3"?

Pipe is ductile iron and will be decant line from sequential batch reactor. Flow will be pressurized by hydraulic head in tank. Tank will contain wastewater. Penetration is lower portion of wall - not sure of elevation yet.

This is the first time I have had to detail something like this and I want to make sure I have taken everything into consideration. I have a 48 inch diameter pipe to be cast into the wall of a concrete tank with a 25 foot high wall. There is also an existing tank where this 48" diameter pipe...

JedClampett, What is the title of the PCA book? Do the additional circumferential bars need added to the bottom of the membrane slab? Thanks.

I will have to adjust my mesh to match the 3:1 ratio. I was using a 33" wall with the 3" mesh Thanks for the help.

Thanks for the response. When you say "reasonable results" do you mean the results are close to published plate results?

I have modelled a 10 ft by 10 ft concrete plate with a hydrostatic load to verify the output against plate formulas in "Roark's Formulas for Stess and Strain" So I can apply to a concrete tank model. Using the quadmesh tool, I need about a 3" mesh before results seem to converge. Is this...

Thanks again for all of the responses. I am going to try kslee1000's suggestion. The wall is 212 ft long by 25 ft tall, so the plate formulas do not apply. That is why I want to design as a vertical cantilever, but did not know how to calculate the induced moment and shear at the corners due...

I also have the PCA book, but the coefficients don't apply due to the size of the tank. I read an older thread that said design as vertical cantilever and use max horizontal coefficients. I was just looking for a method to calculate the reqd. horizontal steel.

Thanks. I was thinking about doing that, but the frame analysis did not seem to apply because the wall is bending vertically and horizontally where a 2-D frame is one directional

Can anyone recommed a book or design guide to calculate by hand the horizontal moment and shear induced at the corners or a rectangular concrete tank with walls designed as vertical cantilevers? I have "Reinforced Concrete Reservoirs and Tanks" by G.P Manning with a graph of the shear and...