Seismic Behaviour of Elevated Water Tanks – A Review

Elevated water tanks are the most important lifeline structures which provides access to water for daily utilities to communities and its elevated position ensures smooth and efficient water supply through gravity. The after-earthquake functionality of such water tanks is the major concern as these tanks must ensure its intended purpose of water supply post-earthquake. Previous earthquakes have shown the various failure patterns of elevated water tanks wherein the water tank geometry, shape, height of staging, and the depth of freeboard provided, effect of sloshing waves, underestimation of forces due to Soil-Structure interaction and improper idealization of water tanks have been the major reasons. Compared to conventional buildings elevated water tanks have a huge mass of water supported on a tall staging due to which its seismic behaviour is contradictory when compared with conventional buildings. Hence there is a need to understand the seismic behaviour and assess its vulnerabilities from which Aseismic design of such tanks can be considered. The present study summarizes the past works carried out on assessing seismic behaviour of elevated water tanks considering various parameters that influences its behaviour.