For water and wastewater treatment tank design, I have been determining the amount of hook development length available for horizontal or vertical wall reinforcing by calculating the distance from the face of the wall/slab to the back of the hook (i.e. available hook development length equals...
I'm trying to figure out how to calculate the factor of safety of a tank floating. Stupid question, right? Ignoring soil friction it is just empty tank weight plus soil weight over slab extension divided by the buoyant volume x 62.4 pcf. However, I'm double checking some calculations of a...
How have all of you concrete tank designers out there been modifying the tables in PCA's Rectangular Concrete Tank publication when the operating water surface is well above the top of the tank wall (i.e. significant freeboard)? Do you just assume that the top of the concrete tank is down at...
On our below-grade tanks, we generally try to use the self weight of tank walls and slabs to prevent tank uplift. However, for the project I am working on now, self weight isn't going to economically work. I was looking into ground water pressure relief valves, and it appears there are two...
Hi everyone,
I have a small clarifier (20ft ID, 12" walls, 66ft wall circumference) I am designing for a WWTP and I am looking at the wall/slab construction joint layout (with waterstops of course). Usually in the water tanks we design, we limit the maximum wall length between vertical...
This is for all of you WWTP designers out there. What mix design have you been using for Headworks structures, or other structures with relatively high exposure to sulfates? We have generally been using the same mix design we use for all watertight structures (f'c = 4,500 psi, w/c = 0.42, Type...
I have been researching the need for a vapor barrier / retarder below slabs-on-grade for environmental tanks (WWTP, WTP, etc.) I have found example drawings from firms that show the use of a vapor barrier below the tanks, while I have found example drawings from other firms that omit the...
