Avaliação do desempenho estrutural de barreiras de segurança de concreto armado para uso em rodovias
Data
2017-11-15
Autores
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Biblioteca Digital de Teses e Dissertações da USP
Universidade de São Paulo
Escola de Engenharia de São Carlos
Universidade de São Paulo
Escola de Engenharia de São Carlos
Resumo
Descrição
As barreiras de concreto são dispositivos utilizados como componentes de segurança em rodovias, que visam absorver o choque lateral de veículos desgovernados, propiciando sua recondução à faixa de tráfego e minimizando os danos aos ocupantes do veículo. Neste trabalho é analisado o desempenho de barreiras de concreto com o uso de modelos experimentais e numéricos baseados nas recomendações das normas brasileiras e internacionais. O estudo consiste em analisar a eficiência estática e dinâmica dessas barreiras. A análise estática engloba o estudo de distribuição de tensões na barreira considerando diferentes tipos de conectores, modo de ruptura, bem como a resistência desses conectores através de ensaios experimentais. Os ensaios são realizados de acordo com os critérios estabelecidos pela norma americana AASHTO LRFD 2012. A análise numérica, realizada com o uso de software de elementos finitos LS-DYNA©, contempla a atuação da geometria e da rigidez da barreira no processo de absorção de energia de impacto entre a barreira e o veículo, a eficiência do seu redirecionamento e adequação para os níveis de contenção estabelecidos em normas internacionais. Os resultados evidenciaram que a geometria da barreira é um fator importante para o desempenho da mesma, e, também que o uso de conectores em barreiras temporárias são primordiais para o bom funcionamento do sistema de contenção.
Concrete barriers are devices used as safety components in roads, which aim at absorbing side impact of unguided vehicles, redirecting them to the traffic lane and minimizing damage to the vehicle occupants. The present work analyzes the performance of concrete barriers through experimental and numerical models based on the recommendations of the Brazilian and international standards. The study consists in analyzing the static and dynamic efficiency of these barriers. The static analysis includes determining the stress distribution and yield lines in the barrier for different types of connectors, as well as studying the resistance of these connectors by performing experimental tests; these tests were conducted according to the criteria established by the American Standard AASHTO LRFD 2012. The numerical analysis, conducted with the commercial finite element software LS-DYNA©, evaluates the effect of geometry and stiffness of the barrier on the energy absorption performance., efficiency in redirecting the vehicles and suitability for providing restraint levels established in international standards. The results showed that the geometry of the barrier is an important factor for the barrier performance. In addition, the use of connectors in temporary barriers is essential for the smooth operation of the containment system.
Concrete barriers are devices used as safety components in roads, which aim at absorbing side impact of unguided vehicles, redirecting them to the traffic lane and minimizing damage to the vehicle occupants. The present work analyzes the performance of concrete barriers through experimental and numerical models based on the recommendations of the Brazilian and international standards. The study consists in analyzing the static and dynamic efficiency of these barriers. The static analysis includes determining the stress distribution and yield lines in the barrier for different types of connectors, as well as studying the resistance of these connectors by performing experimental tests; these tests were conducted according to the criteria established by the American Standard AASHTO LRFD 2012. The numerical analysis, conducted with the commercial finite element software LS-DYNA©, evaluates the effect of geometry and stiffness of the barrier on the energy absorption performance., efficiency in redirecting the vehicles and suitability for providing restraint levels established in international standards. The results showed that the geometry of the barrier is an important factor for the barrier performance. In addition, the use of connectors in temporary barriers is essential for the smooth operation of the containment system.
Palavras-chave
Barreiras de concreto, LS-DYNA, Segurança em rodovias, Testes de Impacto, Concrete barriers, Crash test, LS-DYNA, Safety road