Estudo comparativo do colapso progressivo em estruturas de concreto armado

• Autor(a) principal: Matias, Bergson da Silva
• Data de Publicação: 2016
• 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/68732
• topic: Colapso progressivo; Modelos tridimensionais; Concreto armado; Segurança estrutural; Construção civil - Medidas de segurança

This paper main goal is to show the phenomenon of the progressive collapse and discuss the design approaches used to overcome this problem. Structural safety is one of the main points in Engineering, and it must be continuously studied specially in phenomena with a great catastrophic potential, such as the progressive collapse. Since the 70's, the progressive collapse has been discussed in governmental organs and in academia, which defines the phenomenon as the disproportionate spread of a local damage to a bigger part of a structure. Over the last decades, many studies have been done and some methodological approaches to its prevention have been consolidated. Among these approaches, the "Alternate Load Path" (ALP) consists in guarantying that, after the loss of an element, the structure has the capacity to redistribute the efforts without propagation of the local damage. This method is an object of a deeper analysis in this work. Two comparisons are done applying the ALP and embracing the Linear Static Procedure of the guidelines GSA 2013 in a structure of reinforced concrete, sized by NBR 6118:2014. Firstly, the differences between the original structure (without the consideration of the progressive collapse) and the resized structure to resist the phenomenon are compared. The results showed considerable differences in the robustness of the two structures, verifying that the structure sized by the NBR 6118:2014 would not resist the loss of a column and would collapse. Posteriorly, with the intention of identifying the influence in the redistribution of the internal efforts in the analysis of the progressive collapse, the space frame model was compared with a planar frame model. The results showed that the rigidities closer to the locals of the removal of the cornerstone quite diverged between the two models, which directly influenced in the redistribution of the internal efforts and, finally, in the resize of the structure. It can be concluded that the use of the planar frames in the analysis of the progressive collapse does not correctly represent the behavior of the structure. Therefore, to correct evaluate the progressive collapse, the use of spatial models are indispensable.