Civil Engineering Association

Comparison between Static and Dynamic Analysis of Elevated Water Tank”

Abstract— In earthquake resigns, the elevated water tanks are one of the most important lifeline structures. In major cities & also in rural area, elevated water tanks forms an integral part of water supply scheme. The elevated water tank must functional even after the earthquakes as water tanks are required to provide water for drinking and firefighting purpose. The main object of this paper is, to compare the Static and Dynamic analysis of elevated water tank, to study the dynamic response of elevated water tank by both the methods, to study the hydrodynamic effect on elevated water tank, to compare the effects of Impulsive and Convective pressure results. From detail study and analysis it was found that, for same capacity, same geometry, same height, with same staging system, with same Importance factor & Response reduction factor, in the same Zone; response by equivalent static method to dynamic method differ considerably. Even if we consider two cases for same capacity of tank, change in geometric features of a container can shows the considerable change in the response of tank. As the capacity increases difference between the response increases. Increase in the capacity shows that difference between static and dynamic response is in increasing order. It is also found that, for small capacity of tank the impulsive pressure is always greater than the convective pressure, but it is vice- versa for tanks with arge capacity. Magnitude of both the pressure is different. The effect of water sloshing must be included in the analysis. Free board to be provided in the tank based on maximum value of sloshing wave height. If sufficient free board is not provided, roof structure should be designed to resist
the uplift pressure due to sloshing of water.