RELIABILITY ASSESSMENT OF OVERHEAD TRANSMISSION LINE TOWERS IN THE REPUBLIC OF CROATIA

It is a fact that in some areas of Croatia overhead transmission lines had suffered extensive damage. Transmission line towers in Croatia are still designed by deterministic regulations, and modern European semi-probabilistic standards, though accepted, cannot be used because the Croatian normative aspect has not been adopted yet. An originally made map of damages of the overhead transmission lines in the Republic of Croatia for the period from 1979 till 2010 was used as a basis for the analysis of the current Regulation and modern European standards for calculation of the transmission line towers. The map was made by a systematic study of the Dalekovod Project Ltd.'s archives and includes damages which were caused by wind load, ice load, or a combination of ice and wind loads. The research presented in this paper includes analysis of six lattice steel towers, of which three were damaged, according to the current Regulation, EN 50341-1, and the same with the application of the German normative aspect EN 50341-3-4. Based on the results of the research guidelines for the development of the Croatian normative aspect are suggested.