Assessing seismic performance of mid-rise reinforced concrete buildings using fragility curves

Abstract This paper focuses on the seismic fragility assessment of mid-rise reinforced concrete (RC) residential buildings in Cairo, Egypt. Structural safety is assessed by utilizing the damage that could occur to main components, such as columns and shear walls, and consequently, their failure that may lead to progressive (or partial) collapse of structures under extreme dynamic loads. Behaviors of mid-rise reinforced concrete (RC) buildings, which are designed in accordance with the Egyptian standards, are assessed analytically under the action of seismic loads. As such, non-linear time-history analyses (NLTHA), in addition to pushover analyses, were carried out on three (RC) frames with different number of stories varying from six to ten floors. In addition, fragility curves were developed in order to illustrate the probability of exceeding structural damage due to earthquakes as a function of ground motion indices. The lateral response of previously mentioned (RC) frames are evaluated by utilizing more than eighteen hundred NLTHA considering ten different earthquake records with fourteen peak ground acceleration in addition to the Egyptian response spectrum analysis. The output of this research includes roof drift and base shear histories, which are converted to damage in beams and columns in accordance with FEMA-356 guidelines. Based on statistics and probability distribution functions for the obtained results, fragility curves were then developed, which can be used as an effective tool for planning and implementing retrofit schemes, modifications to codified seismic provisions, seismic mitigation strategies, and for insurance-related applications.