Seismic Fragility Analysis of Frame Structures

A seismic fragility analysis of structures is essential to prediction of the building behavior that is likely to occur during earthquakes. Normally, the probability of failure of a structure over a specified period of time is obtained through a convolution of the fragility curve with the seismic hazard curve for the structure site. The fragility models and damage states probabilities serve as a basis for improving the structural codes and performance-based design. Thus, there is a need for relatively simple procedures for evaluating fragility data for decision-making. In this study, the peak story drifts of a building structure during earthquakes are used as an indicator of structural demands. An analytical solution for evaluating the statistical characteristics of peak story drifts of frame structures during earthquakes is proposed. Based on it, an approximate approach to constructing the seismic fragility curves for various states of damage for frame structures is developed.