Sloshing Assessment of Oil Tanks in Keiyo Petrochemical Industrial Complex under Long-Period Seismic Ground Motion

Abstract

Large tanks for storing petroleum are placed in various locations in Japan. The natural periods of liquid sloshing of these tanks are calculated from their diameters and contained liquid heights. The natural periods are approximately between 5 to 10 seconds and hence, petroleum tanks are affected by long-period seismic ground motion. Thus the sloshing phenomenon, oscillation of the contained liquid, may occur and sometimes fire will be associated. Considering this background, this study focuses on the sloshing phenomenon and the sloshing heights in the 2011 Tohoku-Oki earthquake were calculated to assess the fire risk in the Keiyo petrochemical industrial complex. The long-period ground motion due to the scenario Nankai-Trough earthquake was also employed for sloshing analysis at this site. From the calculation of sloshing heights and overflow amount of oil under various conditions, the method to prevent oil overflow was suggested for future earthquakes.