Abstract
In the 2011 Tohoku tsunami, the number of oil tanks in petrochemical complexes along the coast were damaged by its huge hydrodynamic forces. The detailed mechanism how the tsunami force acts on a specific point or specific member of the grouped tanks has not been sufficiently clarified. The aim of this study is to investigate hydrodynamic tsunami forces acting on oil tanks arranged in a grid system. The possibilities that the hydrodynamic pressure inside the grouped tanks become greater than that acting on a single tank are revealed, and the characteristics of the pressures are found to be depending on the position and arrangement of the grouped tanks. It is also noted that the starting time of water level rise is much affected by the spacing conditions of the tank arrangement.
