Heuristic optimization of cylindrical thin-walled steel tanks under seismic loads

Cylindrical ground supported steel tanks are traditionally applied to store water and inflammable liquids due to their simple structural design, very good behavior under hydrostatic loads, low cost and easy construction. Despite these advantages, thin-walled steel tanks are sensitive to seismic loading. The aim of this work is the simplified, fast and direct optimum seismic design of these special structures, avoiding complicated computational methods such as the finite element or the boundary element methods. This objective is achieved using software developed in-house, where the optimum seismic design is achieved satisfying the stability of these structures under extreme seismic design loads according to the Eurocode 8 or the Greek seismic regulation provisions. The proposed method provides with the most economical dimensions for the tank and its foundation, for a predefined, design liquid volume. The proposed method can be considered as a basis for determining minimum cost seismic design of thin-walled steel tanks that satisfy the structural and stability requirements.