Performance of Medium-Rise Buckling-Restrained Braced Frame Under Near Field Earthquakes

Abstract

Buckling-restrained braced frames (BRBFs) are generally used as lateral load-resisting systems in the seismically active regions. The better energy dissipation capacity and the absence of compressive buckling behaviour of braces in make the BRBFs a preferred alternative over the conventional concentrically braced frames. Most of the past studies focussed on the performance of BRBFs under the far-field earthquakes and concluded that BRBFs may suffer from the larger post-earthquake residual drift as compared to the other systems. This behaviour may be amplified in case of the near-fault earthquakes where long-period pulses and high-frequency contents. In this study, the seismic performance of a medium-rise building of 9-storey has been carried out analytically using SAP2000. The study frame has been designed as per the current seismic code AISC 341-2010 provisions. Forty near-fault ground motions are considered in the nonlinear dynamic (time-hi storey) analysis. The main parameters investigated are inter storey drift response, residual drift response, sequence of hinge formations, and behaviour of beams and columns. The effect of brace configurations, i.e., Chevron and Split-X , are also studied under the same near-fault ground motions.