COMPARISION OF DESIGN OF CIRCULAR WATER TANK BY WSM IS 3370 (1967) AND LSM IS 3370 (2009)

Abstract

Traditionally, the water tanks in India were designed by designed by working stress method, as prescribed in IS 3370-1967.This code was revised in the year 2009 and the code allowed the design of water tanks method by working stress as well as limit state method, as prescribed in IS 3370-2009. This revision was most awaited as the earlier version necessitated the thicker sections to allow the crack free structure. It would be really interesting to discover the changes incorporated in IS3370-2009. In this study, a circular water tank with top and bottom dome is designed with reference to the revised and pre-revised version of IS 3370. It was found in the results that the tank designed by limit state method was economical when designed by IS 3370-2009 when compared with that designed by working stress method based on IS 3370-1967. Also, the provision for calculation of crack width has been prescribed in the revised version of the code. The code allowed the crack width of 0.2 millimeters as limit state of serviceability. It was observed that the steel requirements as per new code was found to be lesser than that in the design by the earlier version.