ESTUDIO DEL COMPORTAMIENTO DE MARCOS DE CONCRETO DE PUENTES URBANOS SOMETIDOS A DISTINTAS INTENSIDADES SÍSMICAS, INCURSIONANDO EN DIFERENTES ESTADOS LIMITE

Abstract

In 1989, some bridges structures suffered major damage during the Loma Prieta earthquake at California. Cypress Street Viaduct was a two-level elevated freeway structure, and it collapsed catastrophically crushing cars and trucks as the second level pancaked onto the firs level. The performance of the viaduct is the particular interest to the bridge design, behavior and research community. The results of time-history analyses indicate that collapse was initiated by a shear failure of the pedestal regions. The significance of this observation is that the upper girder-to-column connections, while probably suffering flexual cracking to shear failure of de pedestals. Had the upper girder-to-column connections failed prior to pedestal failure, by either compressive crushing or bar pullout, the collapse would have likely been in lateral rather than a vertical direction. At the present, viaducts two-level elevated have been built in the Mexico City. San Antonio Viaduct is part of the transport system, and it is linking Miguel Aleman Viaduct with south Periferico. Seismic areas affect the performance of these structures, therefore they could be vulnerable to damage in future earthquakes, it provides an excellent opportunity to evaluate their seismic response and prevent collapsed. This research studies the seismic response and behavior of a RC frame that belongs to the San Antonio distributor freeway; it is obtained the seismic fragility and the statistics of the maximum inter-story drifts, considering different magnitude simulated seismic signals by the empirical Green function method. The Green functions used, corresponds to earthquake registered in 19 April 1989 at Esparza and Oteo. The structure studied is a double frame type with a non uniform mass distribution in height. The frame was analyzed using non-linear behavior