Dynamics of Vertically Excited Liquid Storage Tanks

Abstract

A simple practical procedure is presented for evaluating the dynamic response of an upright circular cylindrical liquid storage tank to a vertical component of ground shaking, considering the flexibility of the supporting medium. The tank is presumed to be supported through a rigid circular mat at the surface of a homogeneous elastic half‐space, and it is analyzed approximately by application of Galerkin's method considering the tank‐liquid system to respond as a single‐degree‐of‐freedom system in its fixed‐base condition. Comprehensive numerical data are included that elucidate the actions of both rigidly and flexibly supported tanks, and the effects of the numerous parameters that influence the response. It is shown that soil‐structure interaction reduces the hydrodynamic effects and that the consequences of such interaction may be approximated with good accuracy by a change in the natural frequency of the tank‐liquid system and by an increase in damping. The maximum hydrodynamic effects are related simply to the corresponding hydrostatic effects.