Avaliação das condições de manutenção e segurança de barragens no interior do estado do Rio Grande do Norte

Abstract

The main purpose of this research was to investigate the security circumstances of six dams in the interior of the state of Rio Grande do Norte: three dams (Calabouço, Gargalheiras e Passagem das Traíras) that were considered in critical situation according to the last Dam Safety Report 2017 by ANA; the most important dam of the state (Armando Ribeiro Gonçalves); and two other dams in the region of Seridó (Boqueirão de Parelhas and Itans). It was also a specific objective of this research doing a comparison between the nowadays situation of those dams and the inspections of Souza (2014) made five years ago. Inspection sheets were used in order to evaluate the conditions of these structures by visual inspections, and the main deficiencies were notified. By the results of the inspections, it can be concluded that there is a lack of maintenance in most of these structures. Among all the problems identified in the dams, excessive vegetation growth was the most common, especially in Calabouço with almost its entire embankment covered with vegetation. Some deficiencies notified by Souza (2014) still remain in Boqueirão de Parelhas, Itans and Passagem das Traíras. There are cases it got worse, for example the flow measurement structures in Boqueirão de Parelhas. Gargalheiras had a structural repair of its body concrete and revitalization of hydromechanics parts, however cracks opened again on the surface of the dam and there are still corrosion in some hydromechanics tubulations. Passagem das Traíras has some problems that can represent risks to its structure integrity, such as the loss of resistance on its downstream facing concrete, cracks on its body and misalignment of expansion joints. Armando Ribeiro Gonçalves had problems related to its maintenance, and indication of erosion at downstream lower region.