What is the water density required for structural design by AWWA Standard?
What is the water density required for structural design by AWWA Standard?
(OP)
Good morning, Everybody:
Does anybody happen to Possess AWWA Standard or know the water density required for structural design by AWWA Standard? I know it varies with temperature but will not exceed 62.5 pcf and we usually base on 65pcf to design water tank structure. However this water container structure need to meet AWWA Standard. I looked at website and find AWWA Standard costs over 10,000$ which apparently beyond our budget.
Thank you very much in advance for your help.






RE: What is the water density required for structural design by AWWA Standard?
RE: What is the water density required for structural design by AWWA Standard?
Thank you very much for your input. The reason I asked this question is I have studied a competitor's design, and found their water tank design is nearly 40%---50% overkill in hoop tension capacity than necessary by using 65pcf density. According to customer, the water tanks were required to meet AWWA Standard, which makes me wonder if AWWA Standard requires a higher than 65pcf density in water tank structure design.
RE: What is the water density required for structural design by AWWA Standard?
BA
RE: What is the water density required for structural design by AWWA Standard?
I have done the civil (not structural) design for about a dozen ground-level, welded steel tanks for potable and reclaimed water. As I recall, all of the structural designs for these tanks used either 62.4 pcf or your slightly more conservative 65 pcf. Also, all of my tanks have been in California, so seismic was a big deal. Is seismic a factor for your tank?
However, if you are looking at a reinforced concrete tank for a waste water treatment plant, ACI 350 mandates higher load multipliers for moment calculations than we use for standard Ultimate Strength design (IIRC, these higher multipliers do not apply to shear and I don't know about hoop tension; unfortunately, I don't have a copy handy to verify). A higher density using standard load multipliers could have the same effect that you are seeing, at least for moments.
Finally, AWWA D100 (2005), which I have on this computer, says, under Sec. 3.1 Design Loads: "3.1.2 Water load. Water load shall be the weight of all of the water when the
tank is filled to the TCL. The unit weight used for water shall be 62.4 lb/ft3 (1,000 kg/m3). The weight of water in a wet riser, which is supported directly on
foundations, shall not be considered a vertical load on the riser." BTW, "TCL" = Top Capacity Level.
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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill
RE: What is the water density required for structural design by AWWA Standard?
If you think that your competitors tank was overdesigned, have you thought that they're designing to code?
Here's the thing. Do you want to go to court defending your leaky tank and testify that buying the AWWA standards was too expensive? How much money do you think that's going to cost your company?
I do this a lot. It worries me that people who need guidance on the weight of water are attempting this.
RE: What is the water density required for structural design by AWWA Standard?
It is the full set of AWWA standards that cost $6k for single user and 10K plus for 2 or more users. A single volume out of the set costs from $100 and up.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: What is the water density required for structural design by AWWA Standard?
RE: What is the water density required for structural design by AWWA Standard?
Yes, I assumed the $10K was for the full set but I didn't think the full set would be needed for the structural design. I don't have any experience with AWWA standards, so I don't really know but I did check on the internet and found that one of the documents was for structural design and it was available for $112.
BA
RE: What is the water density required for structural design by AWWA Standard?
RE: What is the water density required for structural design by AWWA Standard?
RE: What is the water density required for structural design by AWWA Standard?