Nonlinear Rocking Analysis of Unanchored Cylindrical Tanks (1st Report, Uplift Deformation of Bottom Plate Subjected by Overturning Moment)

Abstract

When an earthquake hitting, the part of the bottom plate of the unanchored cylindrical tank will be lifted up from the foundation so that no resistance mechanism is existed against the uplift force caused by the overturning moment. The high stresses will be yielded in the bottom plate and the shell plate. This report concerns those problems. The calculation model was made in order to obtain the uplift resistance force, the uplift height, the reaction force from the foundation and the uplift region. In this model, the uplift region was considered as crescent shape, and the elasto - plastic, large deformation effect and the contact problem of the bottom plate was considered. From the comparison between this calculation model and the static tilt test of a thin bottom plate model tank, the calculation result was good agreement with the test. © 1984, The Japan Society of Mechanical Engineers. All rights reserved.