1976 Volume 2 Issue 4 Pages 387-393
Uneven settlement of oil storage tanks has been a big social problem since heavy oil flooded into the Setonaikai Sea by an accidental oil tank rupture. Therefore, we tried to analyse the stress induced in an oil storage tank which has a record of uneven sinking into the foundation. The settlement of an oil storage tank which was constructed on December '61, and had shown uneven sinking when full of water is reexamined minutely and the data are used as input for the displacement constraint at the element node of the bottom plate in computer analysis. The verification of the program is carried out by solving for a circular plate on elastic foundation and under concentrated load.
A detailed stress and deformation analysis is carried out by the finite element method. Numerical results elucidate the feature of deformation and stress distribution, and it is found that the maximum shearing stress exceeds the yield point in the annular region of the bottom plate. Thus welded specimen models of the most heavily stressed part are built and bending as well as fracture tests are conducted to assess the allowance for safety of the storage tank.