Analysis of Structural Behavior in Elevated Tanks Through the Configuration of Viscous Fluid Dissipators

Storage tanks are critical structures that must remain operational following seismic events to supply water for human consumption and firefighting. However, past events such as the Loma Prieta earthquake in 1989, the Kocaeli earthquake in 1999, and the Northridge earthquake in 1994 have led to the collapse of these tanks due to the dynamic effects of liquids, especially the convective mass at the top of the tank. To address these challenges, various researchers have proposed adding components to dissipate energy and reduce lateral displacements of elevated tanks. This study focuses on analyzing the structural behavior of these tanks by incorporating viscous fluid dissipators. An analysis was conducted according to relevant regulations, including the Peruvian seismic-resistant design standard E.030 for the city of Huancavelica, Peru, which is located in a soft soil zone. Additionally, guidelines established in the ACI 350.3-20 standard for the design of concrete structures containing liquids were used to obtain parameters for a 100 m³ elevated water tank with a total height of 21.4 m from ground level to the roof. Five configurations of viscous fluid dissipators were considered: diagonal, enhanced chevron, horizontal chevron, horizontal chevron type 2, and toggle brace. These configurations underwent a nonlinear seismic history analysis, following the moderate performance methodology with a target drift of 0.0058, according to the Hazus 2010 standard. The study's results revealed that the horizontal chevron type 2 model exhibited better dynamic behavior, reducing floor drift by 52.72%. Additionally, the enhanced chevron model reduced floor acceleration by between 19% and 23%. Regarding tank walls, a 5% reduction in moment relative to the design envelope was observed. In the total system, an energy dissipation of 61.15% was achieved, with a maximum dissipator displacement of 16 mm along its local axis.