Answered Identify main rod and distributed rod

In case of slabs the main bars are those which are placed along shorter span or direction and distribution bars are those which are placed along longer span.As the base of water tank is also designed as slab memeber so it will be the same case for water tanksand also regarding the footing the same case is followed.
 
In case of slabs the main bars are those which are placed along shorter span or direction and distribution bars are those which are placed along longer span.As the base of water tank is also designed as slab memeber so it will be the same case for water tanksand also regarding the footing the same case is followed.
Thank you sir...
but in most area the footing shape is square..and use same dia rods for both ways...then how to find it sir..??