Summary and conclusions
This paper examined the seismic behavior of two steel eccentrically braced frames (EBF) assumed to be located at a soft soil site in Mexico City. The EBFs were designed to satisfy the lateral strength and stiffness requirements of the 2004 Edition of the Technical Requirements for Seismic Design prescribed in the Mexico City Building Construction Code. The analytical models of the EBFs, beams, columns, and braces were modeled using a distributed plasticity approach, while the links were modeled using a modeling strategy that simulate shear plastic hinges. In addition, the hysteretic response of the links considered a failure criterion (i.e. the links exhaust their shear capacity when an inelastic plastic rotation equal to 0.06 rad is reached during cyclic loading), which is consistent with its experimental response. Due to the scarcity of enough recorded mainshock-aftershock sequences at soft soil sites, three sets of artificial sequences with different intensity ratio, VA/ VM (i.e. ratio of the intensity of the aftershock with respect to the mainshock, considering that the mainshocks are scaled to reach the highest PGV recorded during the September 19, 1985 earthquake in Mexico City) were generated as part of this study.
