Seismic dem,evaluation of the reinforced concrete elevated water tanks

Elevated water tanks as one of the main lifeline elements are the structures of high importance. Since they are extremely vulnerable under lateral forces, their serviceability performance during and after strong earthquakes is a matter of concern. As such, in recent years, the seismic behavior of water tanks has been the focus of a significant amount of studies. According to the literature review, it has been realized that although many studies have been investigated the effects dynamic characteristics of structure, only a few studies have been conducted on the seismic behavior of the elevated water tanks. In The current study, three reinforced concrete elevated water tanks, with a capacity of 900 cubic meters and Height of 25, 32 and 39 meters have been utilized and subjected to an ensemble of earthquake records. The behavior of concrete material was assumed to be nonlinear. Seismic demand of the elevated water tanks for a wide range of structural characteristics has been assessed. The obtained result revealed that scattering of responses in the mean minus standard deviation and mean plus standard deviation are approximately 60 to 70 percents Moreover, simultaneous effects of mass increase and stiffness decrease of tank staging led to increase in the base shear, overturning moment, displacement and hydrodynamic pressure Equal to 10 to 20 %, 13 to 32 %, 10 to 15 % and 8 to 9 %, respectively.