Best combination of stiffness and strength ratios for seismic design of buildings with BRBs

Abstract

A probabilistic evaluation of seismic structural performance, considering economic losses related to repair cost and downtime (occupancy interruption) of steel moment-resisting frames (MRFs) equipped with buckling-restrained braces (BRBs) is conducted. The assessment considers expected total costs throughout the 50-year lifespan of the dual systems. The probabilistic assessment is carried out for groups of 6-, 9-, and 12-story office buildings, considering different combinations of design parameters resulting from the combination of the stiffness and strength ratios (α and γ, respectively) between the MRFs and the BRBs. Based on the findings, recommended best values of the design parameters α and γ are proposed, aiming to minimize the total expected costs of the buildings.