Abstract
Fragility curves as a powerful tool assess the possible damage to existing structures and estimate the probability of structural damage exceeding a given level of seismic damage for several levels of seismic ground motions. This paper tries to evaluate the seismic vulnerability of steel structures containing relatively new Linked Column Frame using the fragility curves under the critical multiple earthquakes, which are not considered by most of the seismic design codes. Therefore, 10 LCF steel frames with shear/flexural behavior and length of 2 meters have been designed and implemented in OpenSees software. After selecting consecutive critical earthquakes, the fragility curves for single and consecutive scenarios have been calculated. For more comprehensively evaluation of the mentioned structures, the effect of various parameters including the number of stories and behavior of the linked beams has been investigated. The results indicate an increase in the probability of collapse under a seismic sequence compared to a single earthquake. This increase is more obvious in the performance level corresponding to the collapse threshold. So that the collapse prevention of 7-story frame with flexural linked beam exposed to consecutive earthquakes is 17% higher than the single case.