Projeto de fundações de linhas de transmissão baseado em confiabilidade

Abstract

High competitiveness among several sustainable energy alternatives implies the need to minimize the costs of generation, transmission and distribution of electrical energy. Within this context, the increase of the distances between the generation and distribution, coupled with the fact that the cost of foundations for transmission lines (TL's) can reach 50% of the total cost of the same, it is shown that these components have a prominent role. Despite the necessity of reducing the cost of foundations, this is facing numerous challenges, namely: (i) the identification of the uncertainties associated with multiple variables that affect the behavior of the foundations of TL's; (ii) the consolidation of the methodology for determining the tensile load carrying capacity of these structuralelements; (iii) the appropriate treatment of uncertainties that affect the behavior of the foundations of TL's from concepts and methods of structural reliability; (iv) the development of project semi-probabilistic, i.e. Design based on reliability. The method developed by the University of Grenoble is the most used for verification of tensile load capacity in transmission lines in Brazil and abroad, although the method of Cone is still used. However, these methodologies do not take into account the presence of uncertainties that affect your variables. Consolidation in this technical means of a methodology that takes into account the treatment of uncertainties in probabilistic approach is a challenge. The variables that affect the behavior of the foundations of TL's are, among others, the mechanical properties of soils, methods of testing and analysis of results, models of behavior, interaction soil-structure, etc. For this work were executed 738 tensile load tests on the field in the foundations of 246towers (3 essays per tower). The monitoring and coordination of the author of this thesis in the execution of foundations and tests as well as the choice of sites allowed for a more thorough evaluation of results leading to conclusions more consistent. There were doubts about the quality of the implementation of the foundations and tests. The main objective of this work is to study the behavior of tensile strength of foundations based on tests of prototypes in true greatness run on Brazilian soil to probabilistic description for use in the development of technical standards. The portion of the request (S) and the factor of increase of the loading of the project equation of semi-probabilistic have not been the object of this study.