Seismic design and analysis of reinforced concrete buckling-restrained braced frame buildings with multi-performance criteria

Buckling-restrained braces play a critical role as the first-defendant line in dissipating seismic energy and are often used in concrete frame structures to ensure that the main beam–column members are “undamaged” or significantly elastic during medium earthquakes. The design of the reinforced concrete frame structures with buckling-restrained brace is generally based on the assumption of shear deformation of the structure. The conventional seismic design considers the “second-defendant line design” based on the geometric relationship between the axial deformation and strength of buckling-restrained braces and stratified deformation. This article proposes iterative optimization of the buckling-restrained brace design method and layout scheme based on the nonlinear structural response of the calibrated numerical model, and then approximates the nonlinear structure scheme using a linear method. Time history analyses are performed to prove that the linear design method is highly conservative for estimating seismic intensity, and the proposed design method provides more efficient damage distributions in frame components. The results of the nonlinear performance evaluation and energy analysis indicate that the method proposed in this article can meet the performance design requirements achieving multi-performance criteria.