Seismic Performance of RC Elevated Water Tanks with Frame Staging and Exhibition Damage Pattern

Abstract

The current designs of supporting structures of elevated water tanks are tremendously vulnerable under lateral forces due to an earthquake and the Bhuj (India) earthquake provided another illustration when a great number of water tanks with frame staging suffered damage and a few collapsed. Liquid storage tanks and particularly elevated reservoirs including structures with very high significance and elements of the main arteries are considered. In the past earthquakes, it has been identified that the reinforced concrete water tanks under lateral earthquake loads have been extremely susceptible, so that in some cases, these tanks had suffered collapse. According to the studies it was found that current detriment in frame staging, creating plastic hinges in beams and columns and created deep cracks in the columns which are in place to connect container. In this paper, at first by studying the losses occurred in reservoirs during past earthquakes, the reasons for these occurred damages studied and then so provide patterns for these damages in structures. In comparison with reinforced concrete elevated water tanks with shaft staging, the reinforced concrete elevated water tanks with frame staging have shown better seismic behavior to resistant against lateral loads. Considering the fact that damage pattern recognition is necessary to the appropriate analyze in reservoirs in the methods of nonlinear and dynamic, so the main objective of this paper is to obtain the damage pattern in reservoirs for using in analytical methods. In this paper, a sample of a reinforced concrete elevated water tank, with 900 cubic meters under one earthquake record have been studied and analyzed using dynamic time history analysis. It was determined which failure modes of shear forces in beams and also, failure modes of axial force are dominant in this reservoir.