2209 Strength evaluation for double deck floating roof of oil storage tank against sloshing due to earthquake

Abstract

Structural integrity assessment method for floating roof of oil tank against semi-long period (2-15 sec.) ground motion is presented. To obtain the roof motion and maximum dynamic pressure profile loaded on lower roof deck from oscillating oil during earthquake, structure-fluid coupled analysis between roof and oil was conducted with actual waveform of the Tokachi-Oki earthquake in 2003. Detailed stress analysis with non-liner FEM for floating roof was performed to evaluate buckling and welded joint strength of floating roof component. It is concluded that strength assessment results of welded joint is good agreement with observed actual damage of oil tank.