Aplicação da ferramenta de risco FMEA para análises dos modos de falha de uma barragem de terra: estudo de caso Projeto Formoso do Araguaia-TO

Abstract

The Formoso River Project, located in the state of Tocantins, is the largest irrigation project in Latin America and its structures, made up of three dams, have worried the supervisory body due to the compromised state of conservation of these structures, with evidence of pathologies and anomalies at various points. The state government, which is the developer of the dams, in 2012 even contracted revitalization projects for the enterprise, but to date the works have not been carried out, which makes the safety of the dams more vulnerable. The general objective of the research is to analyze the risk situation of the Calumbi II dam, which makes up the Rio Formoso irrigation project, through the application of the FMEA (Failure Mode and Effects Analysis) risk tool, identifying the most likely failure modes and with greater potential. Other objectives would be: the description of the interventions recommended by the consultancy hired by the entrepreneur and the critical analysis of the lack of dam safety management. The research methodology was based on four stages: a) characterization of the Rio Formoso Project and the case study dam; b) survey of anomalies and pathologies found in the dam; c) application of the FMEA risk tool and d) critical analysis of the dam's safety management case study. The results indicated that the Calumbi II dam presents several pathologies and anomalies (presence of large trees and shrub vegetation on the crest, retraction cracks, erosion and water surges on the slopes), and that despite the dam operating at minimum levels, failures may occur. The FMEA tool demonstrated that the highest priority failure mode would be upstream slope instability (NPR=336), secondly, failure due to piping (NPR=320) and thirdly, but more remote, failure due to dam overtopping ( NPR=144). From the aspect of the analysis of the safety management of the Calumbi II Dam, the vulnerability of the enterprise was concluded, since the dam does not have a PSB or PAE, it does not have installed instrumentation, there is no professional responsible for safety, it does not have studies of risk assessments, does not receive regular periodic inspections by the supervisory body.