Análisis a rotura de estribos de fábrica

Abstract

Este artículo estudia el colapso de estribos de fábrica sometidos a cargas laterales puntuales. Dada la falta de resistencia a tracción de la fábrica, en el momento de colapso se forma una fractura que disminuye significativamente la resistencia al vuelco. Considerando la fábrica como un continuo, infinitamente resistente a compresión, sin resistencia a tracción y suponiendo el deslizamiento imposible (hipótesis de Heyman para el análisis límite de las estructuras de fábrica), los autores demuestran la forma que tiene la fractura y determinan la carga crítica de colapso para algunas formas típicas de estribo. Se proponen procedimientos generales para el análisis a vuelco de estructuras de fábrica, incluyendo ejemplos de cálculo. Finalmente se tratan métodos posibles para evaluar la seguridad de estribos existentes. Abstract This paper investigates the collapse of masonry buttresses under concentrated lateral loads. A fracture forms at the collapse state, significantly decreasing the resistance to overturning. Conventional analysis assumes that a masonry buttress acts monolithically to resist lateral loads. The current paper demonstrates that this approach is clearly unsafe, and the possibility of a fracture at the collapse state must be considered in the design and assessment of masonry buttresses. By treating the masonry as a continuum, infinitely strong in compression, with no resistance to tension and no possibility for sliding, the authors demonstrate the form of the fracture and determine the critical failure load for typical buttress forms. This approach follows in the tradition of limit analysis of masonry structures as developed by Heyman. General methods are proposed for the overturning analysis of masonry buttresses, and calculation examples are provided. Finally, methods for evaluating the safety of existing buttresses are presented and discussed.