A performance based seismic design method for eccentrically braced frames (EBFs) and
buckling restrained braced frames (BRBFs) is developed herein. The method is a force-
based seismic design one where the design base shear is obtained by using different modal
strength reduction factors for each one of the first four modes of the frame, instead of using a
constant behavior factor for all modes as in all current design codes. These modal strength
reduction factors incorporate the dynamic characteristics of the structure, different soil types …

A new method for the seismic design of plane steel moment resisting frames is developed.
This method determines the design base shear of a plane steel frame through modal
synthesis and spectrum analysis utilizing different values of the strength reduction (behavior)
factor for the modes considered instead of a single common value of that factor for all these
modes as it is the case with current seismic codes. The values of these modal strength
reduction factors are derived with the aid of a) design equations that provide equivalent …