Implementação do método de análise de risco para avaliação da estabilidade de uma barragem de terra instrumentada. Estudo de caso: barragem pesqueiro

• Autor(a) principal: Mesquita, Karlomano Facundo de
• Data de Publicação: 2018
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/40938
• topic: Segurança de barragens; Segurança de barragens; Instrumentação

Dams offer many benefits to our society, but floods resulting from the ruptures of these landfills have also produced some of the most devastating disasters of the last two centuries. In this aspect, the evaluation of the safety of the work through instrumentation occupies a prominent place, allowing to analyze the mechanical behavior during the operational period and allowing the identification of possible anomalies. The instrumentation also allows to evaluate the stability of the mass during the useful life according to the variation of the level of water in the reservoir and by the occurrence of pore-pressure variations inside the mass, however, uncertainties as to the real condition of the stability through evaluations by methods deterministic is plausible due to the variability of the parameters arising from the executive process itself or even related to the heterogeneity of the construction soil. Considering the importance of monitoring dams from instruments, this work proposes the implementation of the method of risk analysis to evaluate the safety of a dam under the probabilistic focus, determining the probability of the instability condition (FS <1.50 ) for various piezometric levels that the busbar may be subjected under anomalous conditions, such as, for example, the sealing of the internal drainage system. For this purpose, the studies were carried out in the fishing dam, present in the metropolitan basin of Fortaleza - CE. The modeling was performed using the Geostudio 2007 software, in which the Morgenstern-Price method was used for the deterministic analyzes of slope stability and the Monte Carlo method for calculating the probability of failure as a function of the piezometric load variation of two piezometers in the maximum section of the dam. The present study also allows the project manager to estimate in real time the probability of instability of the massif from the reading of field data without the need to generate more complex calculation models, thus allowing the adoption of emergency measures with speed if the work have any anomalies. It is verified that the sealing process, induced in a numerical model by reducing the permeability of the filter, directly affects the stability of the earth dam due to the increase of the water table and consequently the increase of the requests in the work. By means of probabilistic analyzes through Monte Carlo simulations carried out by the software Geostudio 2007 itself, it was observed that the probability of failure increases considerably as the piezometric voltages increase in the bus.