Review on Modification of Response Reduction Factor of elevated liquid storage tank

Abstract

The Response Reduction Factor (R) means for the capacity of any structure to dissipate energy through its inelastic Behaviour.  Elevated tank carries large mass at its top in the container. Due to this Elevated tank will have large overturning moments at its base under the action of lateral forces. Tanks of different capacities will dissipate different amount of energy through inelastic Behaviour. Similarly tanks of same capacity under different magnitude of lateral forces will dissipate different amount of energy. Our Indian code suggest a single value of Response Reduction Factor for all type of water tank of single supporting system, irrespective of height of staging or shaft, plan geometry, soil condition/Flexibility and locality cannot be justified. In the latest Indian standard codal provision of IS 1893 (Part 2): 2014 for a single type of framing system only one value of Response Reduction Factor is mentioned for all above parameters. Response Reduction Factor is an Important factor using it, the actual value of base shear of the structure should be reduced to obtained design horizontal or  lateral  force. The various Components of Response Reduction Factor are Ductility factor, over strength factor and Redundancy factor.