SEISMIC RESISTANT DESIGN OF CYLINDRICAL LIQUID STORAGE TANKS

Abstract

This is a paper that summarizes the state of the practice and state of the art in the prediction of seismic behavior of cylindrical liquid storage tanks. It can be divided into five parts. In the first part the seismic performance of these types of tanks during recent   earthquakes is brielfly reviewed. From this review it becomes evident that a large percentage of these tanks have failed or suffered severe damages. The different types of failure are classified into several categories. The second part of the paper discusses the desing of some of the thank that suffered damages andthe state of the practice is summarized by reviewing present seismic code desing provisions. Thirdly, the soundness of these code provisions is analyzed in view of the state of thank.  Results obtained in recent theoretical and experimental investigations of such behavior are summarized and implications regarding needed improvement in seismic desing are assessed. Results from analyses of an existing  thank using different methods are presented and compared. An improved procedure for the practical seismic resistant desing of these thanks is outlined in the fourth part of the paper. A series of practical desing rules which provide extra margins of safety are offered and the extra cost required is discussed. Finally, recommendations for future research to improve the desing and construction of this type of liquid storage thanks are formuated.