Seismic evaluation of low-rise steel building frames with self-centering energy-absorbing rigid cores designed using a force-based approach

摘要

This paper focuses on a new lateral-force-resisting system - the Self-Centering Energy-Absorbing Rigid Core system (denoted as the SCENARIO system)-for achieving enhanced seismic performance and improved post-earthquake reparability in low-rise steel building frames. Friction-Spring Dampers (FSDs) are included in the SCENARIO system to achieve the self-centering feature and dissipate hysteretic energy. Moreover, Buckling Restrained Braces (BRBs) are included in the SCENARIO system to absorb earthquake energy if needed. A design procedure was proposed for the SCENARIO system. Results from Nonlinear Static Analyses (NSA) show that the design procedure can enable the SCENARIO system to exhibit the intended nonlinear behavior. A representative three-story demonstration building was considered in this research to investigate the seismic response of the low-rise steel buildings with the SCENARIO systems to resist the lateral seismic forces. Three designs adopting different response modification factors to determine the design base shears were performed for the demonstration building. Results from Nonlinear Response History Analyses (NRHA) of the considered systems show that the SCENARIO systems can exhibit satisfactory seismic responses when designed with the response modifications factors of 6 and 8 which are assigned to conventional steel braced frames. Moreover, it was found that the residual inter-story drift ratios of the SCENARIO system can be lower than 0.005 rad even under the MCE excitations, creating a satisfactory condition for the post-earthquake repair work if necessary.