Classificação de risco de barragens por índices de risco: um estudo de caso

Abstract

In Brazil, the Federal Law No. 12 334/2010, established the National Policy on Safety of Dams (NPSD), whose goal is to establish a baseline for evaluation and monitoring of the implementation of this policy, serving as an analysis tool of its effectiveness in reducing accidents and improving safety management of the Brazilian dams. The law clarified and strengthened the legal responsibility of the entrepreneur to maintain the dam safety conditions, as well as set the supervisory body, depending on the use that is given to the structure. Also it has defined a set of tools for security management, making them mandatory from now on, and among the instruments established by the resolution CNRH No. 143/2012 is the classification system by risk category and associated potential harm. In this classification system, certain technical characteristics of the dam and of the downstream valley, called descriptors, should be rated resulting in values that assist in the classification of the dam according to risk, this approach being known as a risk index. In this work, two of these indices, the overall risk index and the index of resolution CNRH No. 143/2012, are applied to an earth dam. The results obtained show that these methods are directly related to the type of dam in question and with the local and environmental conditions in which the works are located.