Probabilistic fragility analysis:A tool for assessing design rules of RC buildings

In this work, fragility analysis is performed to assess two groups of reinforced concrete structures. The f irst group of structures is composed of buildings that implement three common design practices; namely, fully infi lled, weak ground story and short columns. The three design practices are applied during the design process of a reinforced concrete building. The structures of the second group vary according to the value of the behavioral factors used to defi ne the seismic forces as specifi ed in design procedures. Most seismic design codes belong to the class of prescriptive procedures where if certain constraints are fulfi lled, the structure is considered safe. Prescriptive design procedures express the ability of the structure to absorb energy through inelastic deformation using the behavior factor. The basic objective of this work is to assess both groups of structures with reference to the limit-state probability of exceedance. Thus, four limit state fragility curves are developed on the basis of nonlinear static analysis for both groups of structures. Moreover, the 95% confi dence intervals of the fragility curves are also calculated, taking into account two types of random variables that influence structural capacity and seismic demand.