Abstract
Powerful tsunami attacked to the northeast coast of Japan due to the Great East Japan Earthquake occurred on March 11, 2011. Some aboveground oil storage tanks (ASTs) were subjected to external pressure due to the tsunami. Wind girders are installed to the shell plates in AST for the prevention of buckling by wind pressure. Although many researches on the buckling of ASTs or cylindrical shells concerning tsunami were made, the effect as reinforced rings of the wind guarders was not taken into consideration in them. This paper presents the bifurcation buckling of shell plates in90, 000m3 AST under both internal and external liquid pressure using the axisymmetric shell finite element method. The buckling external liquid height of AST with wind girder is compared with that without wind girder. As a result, the effect of the wind girder on buckling under external liquid pressure is negligibly small. Furthermore, in order to increase the buckling strength in case the internal liquid is empty, one more ring stiffener is added to the shell plate below the lowest wind girder. The result shows that it is effective to attach a ring stiffener to the low position of the shell plate.
