Advanced Steel Construction

Vol. 3, No. 4, pp. 723-736 (2007)



F. Turcic 1,*, I. Luketina, M. Plisic

1 Civil Engineering Institute of Croatia, Zagreb, Croatia

Department of Steel structures

* (Corresponding author: E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.)


Received: 10 November 2006; Revised: 3 May 2007; Accepted: 15 May 2007




Steel roof structures of two identical cylindrical heating oil tanks, located in Zagreb, Croatia, suffered great deformations and partly collapsed in 1993 and 1994, after two decades of continuous use. The tanks are each 20,000 cubic meters in volume, 45.7 m in diameter, 12.5 m in sheathing height, and each of them has a central column in the middle. The cause of damages has been analyzed. An account is given to poor original design, with respect to relevant influences: all types of loads, adequate static system and boundary conditions for individual load types. Necessary additional calculations have been performed and described. The mechanism of the activation and development of the damages are explained. Solutions implemented in the rehabilitation works are also presented. The results and analyses are presented in detail, as they are deemed highly instructive and of interest to a variety of professionals. The tank type analyzed in this paper can be considered as an internationally typical structure as it has been widely used in many locations worldwide. The authors believe that some of similar failures occurred also in the other locations, but, according to available literature, the corresponding reports have proven to be scarce.


Keywords:Steel tanks, roof structures, collapse, damage, rehabilitation


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