Seismic behavior of code-designed steel moment resisting concentrically braced frames (MRCBFs) in so

Results related to the assessment of force modification factors obtained with pushover analyses of 13 regular steel buildings structured with ductile moment – resisting concentrically braced frames are summarized in this paper. Four-story to 16-story models were designed for the soft soil condition according with Mexico’s Federal District Code (MFDC-04). Different balances between the story shear resisted by the columns with respect to the one resisted by the bracing system were considered. Improved equations are proposed for a more realistic assessment of ductilityand overstrengthforce modification factors.