Cylindrical tanks are fundamental structures used for the storage of liquids. Sloshing caused by earthquakes in tanks without enough Freeboard leads to a liquid impact on the roof of tanks. This study aims to explore the base shear variation due to insufficient Freeboard using experimental and numerical methods. The experimental tests are performed using a cylindrical liquid tank excited by various harmonic loads. The impact of some parameters such as the water height to tank radius ratio and Freeboard on base shear force are investigated by conducting 90 tests. Impulsive and convective masses for simplified mass-spring are modified in numerical models so that experimental and numerical base shear results are consistent. Finally, a simple analytical solution to estimate the reduction of convective mass due to insufficient Freeboard is suggested and validated using experimental results.

This study, investigates the factors impacting on sloshing phenomenon of the tank structures including geometry, burial rate, and installation of T-shaped baffles under two different earthquake records. The results indicate that the tanks with larger dimensions will experience less sloshing height. Moreover, length, height, and the Freeboard, respectively, are effective in lowering the roof force. However, Freeboard plays a more important role comparing with the burial rate of the tank in reducing the roof force. Note that as the Freeboard and burial rate increase, the roof force decreases. The results represent that decreasing the height to length ratio of the tank reduces the maximum sloshing height. Finally, using the energy dissipation ratio concept, it is observed that the tank with baffles shows much better performance with the energy dissipation ratio of about 96%, comparing with the burial approach in which even the tank under 100% burial rate just dissipates less than 50% the energy induced by the sloshing waves.

Sloshing Wave Impact Force (SWIF) caused by liquid motion during seismic excitations is investigated in this paper. When the Freeboard is insufficient, the liquid waves collide to the tank roof on which uplift forces are produced. Due to the complication of sloshing impaction, there is no comprehensive investigation that can clarify the various aspect of this phenomenon. Therefore, most of standards don’t recommend any method to evaluate SWIF. Alternatively, the main approach of related codes and standards is to suggest a required Freeboard in order to prevent collision of sloshing wave to the tank roof instead of evaluating the SWIF. However, suggested Freeboard is too high to meet economic considerations in some cases.Therefore, the impact forces should be reasonably evaluated based on the experimental measurements and analytical solutions. An experimental investigation has been implemented to clarify the influence of various geometrical parameters on the impact roof pressure and force values of a rectangular tank. A series of shaking table tests are conducted for a partially filled rectangular tank under harmonic and different earthquake excitations. The experimental measurements for SWIF are compared with those recommended by code provisions and the effects of various parameters on SWIF are discussed.

In this study, a new type of tank roof form is suggested to reduce the high impact forces caused by sloshing. Using this roof allows the tank designers to consider less Freeboard, which is economically valuable. For this purpose, an experimental investigation has been implemented to evaluate the efficacy of the proposed roof to distribute the contained liquid impact forces in several time stages. In these experimental measurements, a series of shaking table tests are conducted for a partially filled tank under harmonic and various earthquake excitations for both typical and proposed tank roof forms. The liquid impact forces are reasonably evaluated and compared for both types of tank roof. The efficacy of the proposed roof design is validated by experimental results and it is shown that the sloshing loads can significantly be reduced up to an average of 50% for the dimensions considered in the experiments.

Liquid storage tanks are crucial in various applications, such as in industrial processes and water supply systems. It's important to understand how these tanks behave during seismic events to ensure their structural safety. This study examines the force applied to the roof of tanks when the Freeboard is insufficient. To conduct the analyses, the Box-Behnken design of the experiment method was used in the study's design. Tanks were modeled using the finite element method combined with smooth particle hydrodynamics. The interaction of the stored fluid with the roof of the tank was assessed using the penalty technique and the soft constraint algorithm. The analysis results showed that the combination of two parameters, the tank length and seismic stimulation, had the most significant impact. However, the fluid height was deemed a non-influential parameter when there was not enough Freeboard. Additionally, the results showed that the intensity acceleration spectrum accurately reflects the impact of frequency content on roofed tanks.