Seismic Performance Upgrade of Elevated Water Tanks Utilizing Friction Dampers

Abstract

Water storage tanks are essential structures in water distribution supply systems. During an earthquake, the damages incurred to water tanks may lead to disastrous loss of life and property. This is due to the low ductility, redundancy, and low energy dissipation characteristics of these structures in comparison to conventional building structures. In this study, the analytical effectiveness of pall friction dampers is investigated to enhance the seismic resistance capacity of existing and newly constructed elevated water tanks. This study evaluates the performance of three water tanks based on their capacities, namely small (90 m3), medium (600 m3), and large (1,700 m3). The selected elevated reinforced concrete (RC) water tank models are examined for staging heights equal to 16, 20, and 24 m. The main objective of the study is to develop a finite element model of elevated water tanks installed with pall friction dampers considering container weight and water mass using finite element software. Nonlinear time-history analyses of elevated water tanks subjected to an array of different ground motion records are performed. The study evaluates the optimal slip load of the friction dampers required to obtain optimal seismic responses of elevated water tanks. The results exhibit the efficiency of pall friction dampers in mitigating the structural responses of elevated water tanks exposed to seismic loads. The study ultimately concludes that the effectiveness of the pall friction damper is independent of tank capacities, and the efficiency of the damper reduces as the staging height increases.