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[Ramesh Babu G]

In an Elevated Circular Water Tank supported on "n" number of columns...with the columns below the side wall...Is it required to provide a Separate Beam to transfer the load from Floor Slab to the Column ?

Because the Side Wall itself acts as a Beam (deep) to transfer the load from Floor Slab to Column...

If Side Wall alone is sufficient, is there Design to be modified in Side Wall to consider it as Beam ?

Or, is there any reason that the Floor Beam has to be provided ?

[es_jayakumar]

In fact, the vertical walls of an Aqueduct are designed in this fashion (ref : RC Structures by Punmia). The vertical walls are designed for the hydrostatic pressure, as a slab, in the vertical direction, while the same is designed as a beam  in the longitudinal direction, for the span in between the piers / supports. I hope, this principle can be extended to the water tank walls also, provided minimum 200mm thickness is used (Cl.6.1.2 of IS 13920 : 2016) for the wall, that will be considered as a beam curved in plan. Cl.23.3 of IS 456 : 2000 (Slenderness Limit for Beams to Ensure
Lateral Stability) may not be applicable due to the continuous bottom support and the load transfer occurring at bottom. However, may have to check for deep beam action. Other SEFIans please comment on this.

E S Jayakumar

[shivani soman]

yes side walls can be designed as a beam but for that separate beam reinforcement has to be provided, which is sometimes difficult to accommodate in the wall after wall reinforcement(for hydro static force) is provided so it is convenient to provide separate beams.

[es_jayakumar]

The longitudinal reinforcement needed for the beam action will not be much, thanks to the large depth (height of the side wall) available.

E S Jayakumar