Step One:
Determine the design constants such as σcbc, σct, m, σst
Where,
σcbc = permissible compressive stress in concrete
σct = permissible tensile stress in concrete
m = modular ratio
σst = permissible compressive stress in steel
Step two:
Determine:-
- Dimensions of the tank
- Volume of the tank
- Area of the tank (by assuming its depth)
Step three:
Find:-
- Hoop tension, Ht=d x h x D/2
- Area of Steel, Ast= d x h x D/2 σst
Step four:
Thickness of the wall of water tank
Ht= [1000t + (m – 1) Ast] x σct
Step five:
Reduction in hoop steel. The steel calculated in step 3 is for 1m height from the bottom of the water tank. The pressure of water decreases at the top. Hence, steel can be reduced by keeping the same thickness of wall.
Step six:
Distribution steel (vertically placed)
Ast= 0.3% of Ag
Step seven:
Floor of the tank
Provide 0.3% of Ag both ways