Sloshing and Stress Analysis of an API 620 Tank under Seismic Excitation Based on SNI 03-1726-2019: Numerical Evaluation of Code Provisions

Several studies have investigated sloshing due to seismic excitation, mainly focusing on baffle effects and cyclic or recorded seismic loads. This study analyzes the seismic impact on an 80,000 m 3 fuel storage tank in Tuban, East Java. Seismic events can cause fluid sloshing, increasing pressure on the tank walls and roof. Utilizing general-purpose finite element software, the sloshing phenomena are simulated using input dynamic loading in spectral response acceleration representing typical seismic loading per the Indonesian standard (SNI). It compares the traditional API 620 method with numerical simulations, revealing a 38% difference in sloshing height and a 40% difference in dynamic hoop stress. The numerical simulations predict a lower sloshing height due to unaccounted warm gas pressure, while the traditional method estimates less dynamic hoop stress. Although the API 620 method is more straightforward for design, numerical simulations provide a deeper understanding of sloshing pressure effects, enhancing asset integrity assessment.