Nonlinear Seismic Behavior of Elevated Circular Water Tanks

Elevated water tanks are vital infrastructure components in urban and rural water distribution systems, providing essential storage and pressure regulation. However, their elevated position, high center of mass, and susceptibility to lateral forces make them vulnerable to seismic events. This study investigates the nonlinear seismic behavior of reinforced concrete (RC) elevated circular water tanks supported on frame-type staging. The study focuses on evaluating the impact of different bracing configurations, staging heights, and tank geometries on the seismic performance of these structures. Nonlinear time-history analysis was conducted using real earthquake ground motion records to simulate the dynamic response of the tanks. The results demonstrate that the inclusion of bracing systems significantly improves the seismic performance, with single bracing providing the most effective reduction in displacement, velocity, and base shear. Tanks without bracing exhibited the highest lateral displacements and base shear values, indicating the importance of bracing in enhancing structural resilience. The study also highlights the role of staging height and tank geometry in influencing seismic response. The findings underscore the importance of considering nonlinear behavior and fluid-structure interaction for a comprehensive understanding of the dynamic performance of elevated water tanks under seismic loading. This research provides valuable insights for the design and seismic evaluation of elevated water tanks, particularly in seismic-prone regions, and contributes to the development of improved design practices that ensure continued functionality and safety during and after seismic events.