Evaluación de desempeño sísmico de un edificio aporticado de hormigón armado usando el método actualizado del espectro de capacidad FEMA 440

Abstract

Cuenca is a medium city located on an area susceptible of moderate to severeseismic movement. The historical seismicity of the region reveals at least one earthquake that caused serious damage in the city (February 1913; estimated magnitude: 7). This dangerous context and the fact that the built heritage of the city (in particular the historical center) is not provided with the appropriateearthquake-resistancesupplies, creates a scenery of seismic vulnerability. In relation with the built heritage of the city, during the seventies and eighties, porticoedbuildings of reinforced concrete of low-rise were very popular. In this context, this projectfocuses on the seismic evaluation of a four-storyporticoedbuilding of representative features (global geometry, dimensions of members and amounts of reinforcement) of the existing buildings in the city. The proposed building was conceived with fully symmetrical floor. The seismic evaluation was conducted taking into account the guidelines of the capacity spectrum method proposed by the FEMA 440 manual, based on a pushover analysis. The model proposed is in line with the inelasticity concentrated models, considering only the inelastic behavior to the bending of beams and columns. The Ruaumoko program was the tool used for modeling and the pushover analysis, as well as the multispring item, the basis of the conformation of such members. Beginning with the prototype building, there were considered four cases of study according to the resistance of the materials and the hysteretic global model. The main results obtained from the application of the capacity spectrum method FEMA 440 were the maximum displacement demands of the cases studied, these are compared and analyzed. Special emphasis was placed on the collection of bends force-displacement of beams and columns, and the implementation of the capacity spectrum method FEMA 440.