The tapered beam model for bottom plate uplift analysis of unanchored cylindrical steel storage tanks

During severe earthquakes, the most important parameter affecting the uplift response of unanchored tanks is the highly nonlinear behavior of their bottom plates. This study mainly focuses on the investigation of this phenomenon using a tapered beam which is resting on a rigid foundation. Analytical equations of the beam are derived and solved numerically; the results are compared with those of the constant width beam presented in other studies. Convergence difficulties at small uplift lengths are investigated. The solution of the model at zero uplift length is presented, and the effects of shell deformations, due to hydrostatic pressures, on uplift response are investigated.