Keywords: Spherical Liquid Storage Tanks, Industrial Structures, Behaviour Factor, Sloshing Effect, Seismic Design, Earthquake Engineering. Abstract: Spherical storage tanks are widely used for various types of liquids, including hazardous contents; consequently these storage tanks must be adequately designed for seismic actions. While very detailed and specific seismic design rules for cylindrical tanks are provided by several codes, such rules are missing for spherical tanks. This paper describes the results of a survey on existing European and American Codes with regard to their applicability to spherical liquid storage tanks and provides comparison of design outcomes according to these codes. The investigations were performed on an example of an existing spherical tank which was selected to be representative for the current practice. The studies comprised numerical FE modelling and calculation as well as simplified models for the estimation of the dynamic properties of the tank structure. The applicability of behaviour factors was discussed based on proposals made by Eurocode 8. Particular attention was paid to the influence of sloshing effects for which no guidance is given in the codes. The sloshing effects were investigated according to the current state of the art based on available publications. Finally the resistance of the tank was compared to the action effect determined from the European and American codes. The comparison of action effects obtained with and without consideration of sloshing effects showed a rather important influence of these effects on the final results.
