base size and soil requirements
The latest ACI 318 code
has now referred all concrete water containing structures to the ACI 350 code
This has really played havoc with our base sizes. The elimination of zones and
the addition of different earthquake values for each base has made it
difficult to use turnkey plans like we used to. Base sizes now vary so
much based on soils and location that they can no longer be listed. The soils pressures
listed is a guideline and can not be nailed down until a soils report is
obtained and an exact location is pin pointed. These numbers can be used as a
general reference when hiring a soils engineer to evaluate your site.
Please note that the dynamic (earthquake) loads on water reservoirs when
compared to their static loading will be at a much higher ratio than would be
expected in a normal non liquid containing structure. This is due to the
'slosh' affect of water moving within the tank during an earthquake. Have a
soils engineer keep the numbers as high as the soils will allow.
| Tank Size: | Static Pressure | Dynamic Pressure | Tank Size: | Static Pressure | Dynamic Pressure | |
| 14 x 10 | 1000 | 1500 | 20 x 10 | 1000 | 1500 | |
| 14 x 15 | 1500 | 2500 | 20 x 15 | 1500 | 2500 | |
| 14 x 20 | 1800 | 4000 | 20 x 20 | 1800 | 3500 | |
| 14 x 25 | 1800 | 4000 | 20 x 25 | 2000 | 4500 | |
| 14 x 30 | 1900 | 4500 | 20 x 30 | 2000 | 4500 | |
| 14 x 35 | 1900 | 4500 | 20 x 35 | 2100 | 4500 | |
| 14 x 40 | 2000 | 4500 | 20 x 40 | 2100 | 4500 | |
| 14 x 45 | 2100 | 4500 | 20 x 45 | 2200 | 4500 | |
| 14 x 50 | 2200 | 4500 | 20 x 50 | 2400 | 4500 | |
| 14 x 55 | 20 x 55 | |||||
| 14 x 60 | 20 x 60 | |||||
| 26 x 10 | 1000 | 1300 | 30 x 10 | 1000 | 1300 | |
| 26 x 15 | 1300 | 2000 | 30 x 15 | 1400 | 2000 | |
| 26 x 20 | 1700 | 2800 | 30 x 20 | 1800 | 3000 | |
| 26 x 25 | 2000 | 4000 | 30 x 25 | 2200 | 4000 | |
| 26 x 30 | 2200 | 4500 | 30 x 30 | 2400 | 4500 | |
| 26 x 35 | 2300 | 4500 | 30 x 35 | 2400 | 4500 | |
| 26 x 40 | 2300 | 4500 | 30 x 40 | 2400 | 4500 | |
| 26 x 45 | 2300 | 4500 | 30 x 45 | 2400 | 4500 | |
| 26 x 50 | 2300 | 4500 | 30 x 50 | 2400 | 4500 | |
| 26 x 55 | 30 x 55 | |||||
| 26 x 60 | 30 x 60 |
(Tank bases are listed as
Inside shell diameter x inside shell height)
(Pressures are listed as pounds per square foot)
Tank Heights for the 14', 20' and 26' can go up to 75' tall.